Page 4 - Fourth Report on Human Biomonitoring of Environmental Chemicals in Canada

10 Summaries and results for metals and trace elements

10.1 Arsenic

Arsenic (CASRN 7440-38-2) is a naturally occurring element making up a small fraction (0.00015%) of the Earth's crust (ATSDR, 2007a; Emsley, 2001). It is classified as a metalloid, exhibiting properties of both a metal and a non-metal. Arsenic is commonly found as an inorganic sulphide complexed with other metals (CCME, 1997). Arsenic also forms stable organic compounds in its trivalent (+3) and pentavalent (+5) states. Common organic arsenic compounds include monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine, and arsenocholine (WHO, 2001).

Arsenic may enter lakes, rivers, or groundwater naturally through erosion and weathering of soils, minerals, and ores (Health Canada, 2006a). The primary anthropogenic sources of arsenic are the smelting of metal ores, the use of arsenical pesticides, and the burning of fossil fuels (WHO, 2001).

Arsenic is used in the manufacture of transistors, lasers, and semi-conductors, and in the processing of glass, pigments, textiles, paper, metal adhesives, ceramics, wood preservatives, ammunition, and explosives. Historical uses of arsenic include application of lead arsenate as a pesticide in apple orchards and vineyards and arsenic trioxide as a herbicide (ATSDR, 2007a; Health Canada, 2006a). Chromated copper arsenate was formerly used as a wood preservative in residential construction projects, such as playground structures and decks; however, it is now used only for industrial purposes and for domestic wood foundations (Health Canada, 2005a). Organic arsenical herbicides, such as MMA and DMA, are no longer registered for use in Canada (Environment Canada, 2008; Health Canada, 2016d).

The public can be exposed to arsenic through food, drinking water, soil, and ambient air (Environment Canada and Health Canada, 1993a). Food is the major source of exposure with total arsenic concentrations being highest in seafood (IARC, 2012a). Organic forms of arsenic, including arsenobetaine and arsenocholine, make up the majority of arsenic in seafood (Ackley et al., 1999; Leufroy et al., 2011; Ruttens et al., 2012). In other foods, there is growing evidence to suggest that inorganic arsenic may represent the predominant form of arsenic (Batista et al., 2011; CFIA, 2013; Conklin and Chen, 2012; FDA, 2016; Health Canada, 2014c; Huang et al., 2012). Exposure to arsenic may also arise from indoor house dust; levels in dust can exceed levels in soil (Rasmussen et al., 2001). Further, exposure to arsenic may be elevated in populations residing in areas where industrial or natural sources occur.

Inorganic arsenic and organic arsenic are readily absorbed via the oral and inhalation routes of exposure; arsenic in all its forms is not readily absorbed via the dermal route. Absorption of arsenic is much lower for highly insoluble forms of arsenic such as arsenic sulfide, arsenic triselenide, and lead arsenate (ATSDR, 2007a). Following absorption, arsenic appears rapidly in blood circulation where it binds primarily to haemoglobin. Within 24 hours, it is found in the liver, kidney, lung, spleen, and skin. Skin, bone, and muscle represent the major storage organs. In cases of chronic exposure, arsenic will preferentially accumulate in tissues rich in keratin or sulfhydryl functional groups, such as hair, nails, skin, and other protein-containing tissues (HBM Commission, 2003). Metabolism of inorganic arsenic involves an initial reduction of pentavalent to trivalent arsenic followed by oxidative methylation to monomethylated, dimethylated, and trimethylated products, including MMA and DMA (WHO, 2011b). Methylation facilitates the excretion of inorganic arsenic from the body because the end-products MMA and DMA are water soluble and readily excreted in urine (WHO, 2001). Absorbed organic arsenic species do not undergo significant metabolism and are predominantly and rapidly eliminated in urine (WHO, 2001).

Biomarkers of arsenic exposure include the levels of arsenic or its metabolites in blood, hair, nails, and urine (WHO, 2001). Measurements of speciated metabolites in urine expressed either as inorganic arsenic or as the sum of metabolites (inorganic arsenic + MMA + DMA) are generally accepted as the most reliable indicator of recent arsenic exposure (ATSDR, 2007a; WHO, 2001). Measurements of arsenic in urine have been used to identify recent arsenic ingestion or above-average exposures in populations living near industrial point sources of arsenic (ATSDR, 2007a).

Acute oral arsenic exposure may cause gastrointestinal effects in humans as well as pain to the extremities and muscles (Health Canada, 2006a). These symptoms are often followed by numbness and tingling of the extremities and muscular cramping and may progress into burning paraesthesias of the extremities, palmoplantar hyperkeratosis, and deterioration in motor and sensory responses (Health Canada, 2006a).

Chronic exposure to inorganic arsenic has been associated with decreased lung function, non-cancer skin effects, and cardiovascular effects including increased incidence of high blood pressure and circulatory problems (ATSDR, 2007a; Environment Canada and Health Canada, 1993a). In addition, increased incidences of skin cancer and various cancers of the internal organs have been associated with chronic ingestion of inorganic arsenic-contaminated drinking water (Health Canada, 2006a). Much of the evidence on the carcinogenicity of arsenic in humans comes from epidemiological studies conducted in populations consuming high levels of inorganic arsenic through drinking water including those from Taiwan, Chile, and Bangladesh (Health Canada 2006, 2016b). Arsenic and inorganic arsenic compounds are classified as carcinogenic to humans by Health Canada and other international agencies (EPA, 1998; Health Canada, 2006a; IARC, 2012a). More recently, a growing body of evidence suggests that in-utero and childhood exposure to high levels of inorganic arsenic may affect fetal and childhood health and development (EFSA CONTAM Panel, 2009; FAO/WHO, 2011b; FDA, 2016; NRC, 2013). Although the current amount of information regarding developmental effects in humans is relatively limited and presents some conflicting results, the available data do raise concerns surrounding exposure to inorganic arsenic during critical windows of early development (Health Canada, 2016e). Although the majority of assessments on the toxicity of arsenic have concentrated on the inorganic forms, recent studies have highlighted the potential for organic arsenic compounds, in particular the pentavalent DMA, to exert carcinogenic effects (Cohen et al., 2006; IARC, 2012a; Schwerdtle et al., 2003). The International Agency for Research on Cancer (IARC) has classified the methylated arsenic metabolites MMA and DMA as Group 2B, possibly carcinogenic to humans, based on evidence from experimental animals (IARC, 2012a). IARC has also evaluated arsenobetaine and other organic arsenic compounds and found them to be not classifiable as to their carcinogenicity to humans (Group 3) (IARC, 2012a).

Health Canada and Environment Canada concluded that arsenic and its inorganic compounds in Canada may be harmful to the environment and may constitute a danger to human life or health (Environment Canada and Health Canada, 1993a). Inorganic arsenic compounds are listed on Schedule 1, List of Toxic Substances, under the Canadian Environmental Protection Act, 1999 (CEPA 1999). The Act allows the federal government to control the importation, manufacture, distribution, and use of inorganic arsenic compounds in Canada (Canada, 1999; Canada, 2000). Risk management actions under CEPA 1999 have been developed to control releases of arsenic from thermal electric power generation, base-metal smelting, wood preservation, and steel manufacturing processes (Environment Canada, 2010a). Arsenic and its compounds are included as prohibited ingredients on the List of Prohibited and Restricted Cosmetic Ingredients (more commonly referred to as the Cosmetic Ingredient Hotlist or simply the Hotlist). The Hotlist is an administrative tool that Health Canada uses to communicate to manufacturers and others that certain substances, when present in a cosmetic, may contravene the general prohibition found in section 16 of the Food and Drugs Act or a provision of the Cosmetic Regulations (Canada, 1985a; Health Canada, 2015b). The Food and Drug Regulations prohibit the sale in Canada of drugs for human use containing arsenic or any of its salts or derivatives (Canada, 2012c). Further, the leachable arsenic content in a variety of consumer products is regulated under the Canada Consumer Product Safety Act (Canada, 2010a). These regulated consumer products include paints and other surface coatings on cribs, toys, and other products for use by a child in learning or play situations (Canada, 2010b; Canada, 2011b).

Health Canada, in collaboration with the Federal-Provincial-Territorial Committee on Drinking Water, has developed a guideline for Canadian drinking water quality that establishes a maximum acceptable concentration for arsenic in drinking water (Health Canada, 2006a). The guideline was developed based on the incidence of internal (lung, bladder, and liver) cancers in humans and the ability of currently available treatment technologies to remove arsenic from drinking water at or below the guideline level (Health Canada, 2006a). Arsenic is also included in the list of various chemicals analyzed as part of Health Canada's ongoing Total Diet Study surveys (Health Canada, 2013d). The food items analyzed represent those that are most typical of the Canadian diet, and the surveys are used to provide dietary exposure estimates for chemicals that Canadians in different age-sex groups are exposed to through the food supply. The concentration of arsenic in some foods is regulated by Health Canada under the Food and Drug Regulations; the existing maximum levels for arsenic in a variety of beverages including apple juice and bottled water are in the process of being updated (Canada, 2012c; Health Canada, 2014c). The existing maximum levels for arsenic in other foods and beverages are also scheduled for review and update.

In a study carried out in British Columbia to assess the levels of trace elements in 61 non-smoking adults aged 30-65 years, the geometric mean concentration and 95th percentile of total arsenic in urine were 27.8 µg/g creatinine and 175.5 µg/g creatinine, respectively (Clark et al., 2007). In a biomonitoring study carried out in the region of the city of Québec with 500 participants aged 18-65 years, the geometric mean of total arsenic in urine was 12.73 µg/L and in whole blood was 0.95 µg/L (INSPQ, 2004).

Arsenite (+3), arsenate (+5), and methylated metabolites of arsenic (MMA and DMA) were analyzed individually in the urine of Canadian Health Measures Survey (CHMS) cycle 2 (2009-2011), cycle 3 (2012-2013), and cycle 4 (2014-2015) participants aged 3-79 years. The data from these cycles are presented as both µg As/L and µg As/g creatinine. The organoarsenic compounds, arsenobetaine and arsenocholine, were analyzed together in the urine of CHMS cycle 2 (2009-2011), cycle 3 (2012-2013), and cycle 4 (2014-2015) participants aged 3-79 years and arsenocholine was also analyzed alone in cycles 3 and 4. The data are presented as both µg As/L and µg As/g creatinine. Finding a measurable amount of arsenic in urine is an indicator of exposure to arsenic and does not necessarily mean that an adverse health effect will occur.

Table 10.1.1 - Inorganic arsenic species, sum of arsenate, arsenite, dimethylarsinic acid and monomethylarsonic acidFootnote c - Geometric means and selected percentiles of urine concentrations (μg As/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2537 5.3 (4.7-6.0) 2.1 (2.0-2.3) 4.8 (4.2-5.4) 14 (11-18) 22Footnote E (12-33)
3 (2012-2013) 2535 5.4 (4.9-6.0) 2.2 (2.0-2.5) 4.6 (4.2-5.0) 14 (10-18) 21Footnote E (12-31)
4 (2014-2015) 2567 5.3 (4.9-5.9) 2.2 (2.1-2.4) 4.7 (4.2-5.3) 14 (12-16) 20 (15-25)
Males, 3-79 years
2 (2009-2011) 1271 5.5 (4.8-6.4) 2.2 (1.8-2.5) 5.0 (3.9-6.1) 15 (11-19) 22Footnote E (12-32)
3 (2012-2013) 1250 5.6 (5.0-6.3) 2.4 (1.9-3.0) 5.1 (4.4-5.8) 13 (10-15) 19Footnote E (7.9-29)
4 (2014-2015) 1275 5.6 (4.9-6.4) 2.2 (2.0-2.4) 4.9 (4.1-5.7) 15 (12-19) 25Footnote E (15-35)
Females, 3-79 years
2 (2009-2011) 1266 5.1 (4.5-5.8) 2.1 (1.8-2.4) 4.7 (4.2-5.2) 14 (10-18) 22Footnote E (8.9-36)
3 (2012-2013) 1285 5.2 (4.5-6.1) 2.2 (2.0-2.3) 4.3 (3.9-4.7) 16Footnote E (8.2-23) Footnote F
4 (2014-2015) 1292 5.1 (4.6-5.7) 2.3 (2.1-2.5) 4.5 (3.9-5.1) 13 (10-16) 17 (12-23)
3-5 years
2 (2009-2011) 516 5.2 (4.6-5.9) 2.5 (2.3-2.7) 4.6 (4.1-5.1) 11 (7.4-15) 16Footnote E (10-22)
3 (2012-2013) 500 5.0 (4.6-5.4) 2.2 (1.9-2.5) 4.5 (4.0-5.1) 13 (10-16) 19Footnote E (11-26)
4 (2014-2015) 512 5.0 (4.5-5.6) 2.3 (2.0-2.6) 4.6 (4.0-5.1) 12 (9.5-14) 15Footnote E (9.6-21)
6-11 years
2 (2009-2011) 511 5.5 (5.1-6.0) 2.6 (2.3-2.9) 5.4 (4.8-6.1) 12 (9.7-14) 17 (11-23)
3 (2012-2013) 506 5.2 (4.5-6.0) 2.2 (1.7-2.7) 4.9 (4.2-5.6) 11 (7.8-14) 17Footnote E (9.1-25)
4 (2014-2015) 514 5.5 (4.9-6.3) 2.5 (2.0-2.9) 5.0 (4.3-5.7) 13 (8.9-18) 20Footnote E (8.1-32)
12-19 years
2 (2009-2011) 510 5.5 (4.6-6.6) 2.3 (1.9-2.7) 4.8 (3.6-6.0) 15 (11-19) 22Footnote E (12-32)
3 (2012-2013) 510 5.4 (4.7-6.3) 2.4 (2.0-2.9) 4.7 (3.5-5.9) 13 (8.4-17) 20Footnote E (7.7-31)
4 (2014-2015) 506 5.5 (4.7-6.4) 2.4 (1.9-2.8) 4.6 (3.8-5.5) 14 (9.3-18) 19 (14-24)
20-39 years
2 (2009-2011) 355 5.6 (4.6-6.8) 2.1 (1.8-2.4) 5.1 (3.8-6.3) Footnote F 28Footnote E (16-41)
3 (2012-2013) 355 5.8 (5.0-6.6) 2.4 (1.7-3.1) 4.8 (4.1-5.5) 15Footnote E (5.6-25) 31Footnote E (9.7-52)
4 (2014-2015) 362 5.5 (4.9-6.1) 2.2 (1.8-2.6) 4.9 (4.2-5.7) 14 (12-16) 16 (13-20)
40-59 years
2 (2009-2011) 356 4.9 (4.2-5.7) 2.0 (1.6-2.5) 4.2 (3.6-4.9) 12 (9.2-15) 15 (12-19)
3 (2012-2013) 312 5.3 (4.3-6.4) 2.2 (1.8-2.6) 4.5 (3.7-5.3) 15Footnote E (5.6-23) Footnote F
4 (2014-2015) 312 5.1 (4.4-6.0) 2.2 (2.0-2.4) 4.3 (3.4-5.1) 14Footnote E (4.8-23) 23Footnote E (13-32)
60-79 years
2 (2009-2011) 289 5.4 (4.4-6.6) 2.2 (1.9-2.4) 4.7 (4.1-5.4) 16Footnote E (8.9-24) Footnote F
3 (2012-2013) 352 5.3 (4.6-6.2) 2.2 (2.0-2.3) 4.7 (3.8-5.5) 14 (11-17) 22Footnote E (14-31)
4 (2014-2015) 361 5.4 (4.5-6.5) 2.3 (1.9-2.6) 4.8 (3.7-6.0) 15 (10-19) 18Footnote E (6.2-29)

c For each individual within a cycle, the sum of arsenate, arsenite, dimethylarsinic acid, and monomethylarsonic acid is calculated. If the value of a species is less than the limit of detection (LOD), then the imputed value calculated as LOD divided by 2 is used. If all four arsenic species are reported as less than the LOD, then the sum will be the sum of the four imputed values.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.2 - Inorganic arsenic species, sum of arsenate, arsenite, dimethylarsinic acid and monomethylarsonic acidFootnote c (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg As/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2527 5.3 (4.6-6.0) 2.3 (2.1-2.5) 4.7 (4.0-5.4) 13 (9.1-17) 20 (13-27)
3 (2012-2013) 2534 5.5 (4.8-6.3) 2.2 (2.0-2.5) 4.9 (4.4-5.5) 14Footnote E (7.8-21) 26Footnote E (12-39)
4 (2014-2015) 2566 4.8 (4.3-5.4) 2.1 (1.9-2.3) 4.3 (3.8-4.7) 12 (8.7-16) 18 (14-22)
Males, 3-79 years
2 (2009-2011) 1267 4.7 (4.1-5.5) 2.2 (2.0-2.5) 4.2 (3.4-4.9) 10 (8.0-13) 15Footnote E (5.8-24)
3 (2012-2013) 1250 4.6 (4.2-5.1) 2.0 (1.7-2.3) 4.4 (3.7-5.1) 9.6 (7.7-12) 17Footnote E (9.2-24)
4 (2014-2015) 1274 4.4 (3.9-5.0) 2.0 (1.8-2.3) 3.9 (3.5-4.4) 10 (7.3-13) 15 (11-19)
Females, 3-79 years
2 (2009-2011) 1260 5.8 (5.1-6.8) 2.4 (2.1-2.8) 5.3 (4.5-6.1) 15 (10-21) 22Footnote E (14-30)
3 (2012-2013) 1284 6.6 (5.5-8.0) 2.5 (2.2-2.9) 5.8 (4.8-6.7) 19Footnote E (5.6-33) 33Footnote E (18-49)
4 (2014-2015) 1292 5.3 (4.5-6.1) 2.4 (2.0-2.7) 4.7 (4.1-5.4) 14 (9.0-18) 20 (15-25)
3-5 years
2 (2009-2011) 515 9.1 (8.1-10) 4.6 (4.0-5.2) 8.0 (7.0-8.9) 19 (15-24) 29Footnote E (13-45)
3 (2012-2013) 499 9.6 (8.8-10) 4.7 (4.2-5.2) 8.7 (7.9-9.5) 20 (15-25) 29Footnote E (13-45)
4 (2014-2015) 512 8.7 (8.0-9.5) 4.2 (3.6-4.8) 7.9 (7.2-8.6) 19 (15-23) 26 (18-34)
6-11 years
2 (2009-2011) 509 6.4 (5.8-7.1) 3.2 (2.9-3.5) 5.9 (5.2-6.5) 14 (10-17) 23Footnote E (14-31)
3 (2012-2013) 506 6.6 (5.8-7.5) 3.4 (3.1-3.7) 5.9 (5.3-6.5) 13 (9.2-17) 17Footnote E (9.8-25)
4 (2014-2015) 513 6.1 (5.5-6.7) 3.0 (2.8-3.3) 5.5 (4.9-6.0) 14 (9.9-18) 18Footnote E (11-25)
12-19 years
2 (2009-2011) 508 4.2 (3.6-5.0) 1.9 (1.6-2.2) 3.6 (3.0-4.2) 12Footnote E (6.7-16) 17Footnote E (9.4-26)
3 (2012-2013) 510 4.1 (3.3-5.0) 1.9 (1.7-2.1) 3.5 (2.8-4.1) 10Footnote E (5.5-15) 17Footnote E (9.4-24)
4 (2014-2015) 506 4.0 (3.5-4.5) 1.7 (1.4-2.0) 3.6 (3.0-4.2) 9.1 (6.3-12) 13Footnote E (8.0-18)
20-39 years
2 (2009-2011) 353 4.8 (3.8-5.9) 2.3 (1.9-2.6) 3.9 (2.7-5.1) 12Footnote E (4.2-21) 21Footnote E (12-31)
3 (2012-2013) 355 4.4 (3.8-5.1) 1.8 (1.3-2.3) 3.8 (3.0-4.5) Footnote F Footnote F
4 (2014-2015) 362 4.4 (3.8-5.1) 2.0 (1.8-2.3) 3.9 (3.3-4.5) 10 (6.6-14) 15Footnote E (7.5-22)
40-59 years
2 (2009-2011) 354 5.0 (4.5-5.6) 2.3 (2.0-2.5) 4.6 (3.8-5.5) 10 (7.6-13) 14Footnote E (9.2-20)
3 (2012-2013) 312 6.2 (5.1-7.6) 2.5 (2.2-2.9) 5.7 (4.7-6.8) Footnote F Footnote F
4 (2014-2015) 312 4.7 (3.9-5.5) 2.1 (1.7-2.4) 4.2 (3.8-4.6) 11Footnote E (5.1-17) 19Footnote E (9.6-29)
60-79 years
2 (2009-2011) 288 6.4 (5.2-7.8) 2.5 (2.1-3.0) 6.0 (4.7-7.3) 16Footnote E (6.2-25) 26Footnote E (8.6-43)
3 (2012-2013) 352 6.0 (4.9-7.2) 2.6 (2.1-3.2) 5.1 (4.0-6.2) Footnote F 27Footnote E (15-40)
4 (2014-2015) 361 5.2 (4.5-6.1) 2.3 (2.1-2.5) 4.5 (3.5-5.5) 13 (9.2-16) 19Footnote E (10-28)

c For each individual within a cycle, the sum of arsenate, arsenite, dimethylarsinic acid, and monomethylarsonic acid is calculated. If the value of a species is less than the limit of detection (LOD), then the imputed value calculated as LOD divided by 2 is used. If all four arsenic species are reported as less than the LOD, then the sum will be the sum of the four imputed values.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.3 - Arsenate - Geometric means and selected percentiles of urine concentrations (μg As/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2538 99.49 - <LOD <LOD <LOD <LOD
3 (2012-2013) 2536 99.25 - <LOD <LOD <LOD <LOD
4 (2014-2015) 2567 98.95 - <LOD <LOD <LOD <LOD
Males, 3-79 years
2 (2009-2011) 1271 99.37 - <LOD <LOD <LOD <LOD
3 (2012-2013) 1251 99.04 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1275 98.82 - <LOD <LOD <LOD <LOD
Females, 3-79 years
2 (2009-2011) 1267 99.61 - <LOD <LOD <LOD <LOD
3 (2012-2013) 1285 99.46 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1292 99.07 - <LOD <LOD <LOD <LOD
3-5 years
2 (2009-2011) 516 98.84 - <LOD <LOD <LOD <LOD
3 (2012-2013) 500 98.60 - <LOD <LOD <LOD <LOD
4 (2014-2015) 512 98.44 - <LOD <LOD <LOD <LOD
6-11 years
2 (2009-2011) 511 99.61 - <LOD <LOD <LOD <LOD
3 (2012-2013) 507 99.61 - <LOD <LOD <LOD <LOD
4 (2014-2015) 514 98.64 - <LOD <LOD <LOD <LOD
12-19 years
2 (2009-2011) 510 99.41 - <LOD <LOD <LOD <LOD
3 (2012-2013) 510 98.82 - <LOD <LOD <LOD <LOD
4 (2014-2015) 506 98.42 - <LOD <LOD <LOD <LOD
20-39 years
2 (2009-2011) 355 99.44 - <LOD <LOD <LOD <LOD
3 (2012-2013) 355 99.72 - <LOD <LOD <LOD <LOD
4 (2014-2015) 362 99.45 - <LOD <LOD <LOD <LOD
40-59 years
2 (2009-2011) 357 100 - <LOD <LOD <LOD <LOD
3 (2012-2013) 312 99.04 - <LOD <LOD <LOD <LOD
4 (2014-2015) 312 99.68 - <LOD <LOD <LOD <LOD
60-79 years
2 (2009-2011) 289 100 - <LOD <LOD <LOD <LOD
3 (2012-2013) 352 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 361 99.72 - <LOD <LOD <LOD <LOD

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

Table 10.1.4 - Arsenate (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg As/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2528 99.49 - <LOD <LOD <LOD <LOD
3 (2012-2013) 2535 99.25 - <LOD <LOD <LOD <LOD
4 (2014-2015) 2566 98.95 - <LOD <LOD <LOD <LOD
Males, 3-79 years
2 (2009-2011) 1267 99.37 - <LOD <LOD <LOD <LOD
3 (2012-2013) 1251 99.04 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1274 98.82 - <LOD <LOD <LOD <LOD
Females, 3-79 years
2 (2009-2011) 1261 99.61 - <LOD <LOD <LOD <LOD
3 (2012-2013) 1284 99.46 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1292 99.07 - <LOD <LOD <LOD <LOD
3-5 years
2 (2009-2011) 515 98.84 - <LOD <LOD <LOD <LOD
3 (2012-2013) 499 98.60 - <LOD <LOD <LOD <LOD
4 (2014-2015) 512 98.44 - <LOD <LOD <LOD <LOD
6-11 years
2 (2009-2011) 509 99.61 - <LOD <LOD <LOD <LOD
3 (2012-2013) 507 99.61 - <LOD <LOD <LOD <LOD
4 (2014-2015) 513 98.64 - <LOD <LOD <LOD <LOD
12-19 years
2 (2009-2011) 508 99.41 - <LOD <LOD <LOD <LOD
3 (2012-2013) 510 98.82 - <LOD <LOD <LOD <LOD
4 (2014-2015) 506 98.42 - <LOD <LOD <LOD <LOD
20-39 years
2 (2009-2011) 353 99.44 - <LOD <LOD <LOD <LOD
3 (2012-2013) 355 99.72 - <LOD <LOD <LOD <LOD
4 (2014-2015) 362 99.45 - <LOD <LOD <LOD <LOD
40-59 years
2 (2009-2011) 355 100 - <LOD <LOD <LOD <LOD
3 (2012-2013) 312 99.04 - <LOD <LOD <LOD <LOD
4 (2014-2015) 312 99.68 - <LOD <LOD <LOD <LOD
60-79 years
2 (2009-2011) 288 100 - <LOD <LOD <LOD <LOD
3 (2012-2013) 352 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 361 99.72 - <LOD <LOD <LOD <LOD

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

Table 10.1.5 - Arsenite - Geometric means and selected percentiles of urine concentrations (μg As/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2537 75.60 - <LOD <LOD 1.7 (1.1-2.3) 2.7Footnote E (1.3-4.0)
3 (2012-2013) 2535 73.96 - <LOD <LOD 1.7Footnote E (0.92-2.5) Footnote F
4 (2014-2015) 2567 70.63 - <LOD <LOD 1.9 (1.5-2.3) 2.7 (2.1-3.4)
Males, 3-79 years
2 (2009-2011) 1271 72.54 - <LOD <LOD 1.7 (1.1-2.3) 2.8Footnote E (0.88-4.7)
3 (2012-2013) 1250 71.20 - <LOD <LOD 1.4 (1.0-1.8) Footnote F
4 (2014-2015) 1275 69.02 - <LOD <LOD 2.2 (1.7-2.6) 3.0 (2.3-3.8)
Females, 3-79 years
2 (2009-2011) 1266 78.67 - <LOD <LOD 1.5Footnote E (0.72-2.3) 2.4Footnote E (1.1-3.7)
3 (2012-2013) 1285 76.65 - <LOD <LOD Footnote F Footnote F
4 (2014-2015) 1292 72.21 - <LOD <LOD 1.5 (1.1-2.0) 2.4Footnote E (1.3-3.5)
3-5 years
2 (2009-2011) 516 84.50 - <LOD <LOD 0.79Footnote E (<LOD-1.2) 1.3Footnote E (0.74-1.9)
3 (2012-2013) 500 81.80 - <LOD <LOD 0.94 (<LOD-1.2) 1.9Footnote E (0.75-3.0)
4 (2014-2015) 512 80.47 - <LOD <LOD 1.1 (0.84-1.3) 1.8Footnote E (1.0-2.5)
6-11 years
2 (2009-2011) 511 78.86 - <LOD <LOD 1.0Footnote E (<LOD-1.4) 1.8Footnote E (1.1-2.4)
3 (2012-2013) 506 76.09 - <LOD <LOD 1.1 (0.81-1.4) 1.6Footnote E (0.82-2.5)
4 (2014-2015) 514 75.88 - <LOD <LOD 1.5Footnote E (0.92-2.0) 2.6Footnote E (1.2-4.0)
12-19 years
2 (2009-2011) 510 72.35 - <LOD <LOD 1.9Footnote E (1.2-2.7) Footnote F
3 (2012-2013) 510 68.43 - <LOD <LOD 1.5Footnote E (<LOD-2.3) 2.6Footnote E (1.1-4.0)
4 (2014-2015) 506 62.25 - <LOD <LOD 2.1Footnote E (1.2-3.0) 3.2 (2.1-4.4)
20-39 years
2 (2009-2011) 355 69.86 - <LOD <LOD 1.9Footnote E (<LOD-3.1) Footnote F
3 (2012-2013) 355 70.70 - <LOD <LOD Footnote F Footnote F
4 (2014-2015) 362 62.71 - <LOD <LOD 2.3 (1.7-2.8) 3.0 (2.3-3.8)
40-59 years
2 (2009-2011) 356 70.51 - <LOD <LOD 1.3Footnote E (0.75-1.8) 2.0Footnote E (1.0-2.9)
3 (2012-2013) 312 70.19 - <LOD <LOD Footnote F Footnote F
4 (2014-2015) 312 70.83 - <LOD <LOD 1.6Footnote E (1.0-2.3) 2.3Footnote E (1.5-3.2)
60-79 years
2 (2009-2011) 289 73.01 - <LOD <LOD 1.9Footnote E (1.1-2.7) Footnote F
3 (2012-2013) 352 74.43 - <LOD <LOD 1.8 (1.1-2.4) 3.2Footnote E (1.3-5.2)
4 (2014-2015) 361 68.70 - <LOD <LOD 1.8 (1.2-2.3) Footnote F

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.6 - Arsenite (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg As/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2527 75.60 - <LOD <LOD 2.0 (1.6-2.3) 2.9 (1.9-3.9)
3 (2012-2013) 2534 73.96 - <LOD <LOD 1.9Footnote E (1.2-2.7) Footnote F
4 (2014-2015) 2566 70.63 - <LOD <LOD 1.6 (1.3-1.9) 2.2 (1.5-2.9)
Males, 3-79 years
2 (2009-2011) 1267 72.54 - <LOD <LOD 1.4Footnote E (0.85-1.9) Footnote F
3 (2012-2013) 1250 71.20 - <LOD <LOD 1.2 (0.94-1.5) Footnote F
4 (2014-2015) 1274 69.02 - <LOD <LOD 1.5 (1.0-1.9) 2.0 (1.4-2.6)
Females, 3-79 years
2 (2009-2011) 1260 78.67 - <LOD <LOD 2.2 (1.6-2.8) 3.0 (2.1-3.9)
3 (2012-2013) 1284 76.65 - <LOD <LOD 2.4Footnote E (<LOD-3.9) Footnote F
4 (2014-2015) 1292 72.21 - <LOD <LOD 1.7 (1.2-2.1) 2.6Footnote E (1.4-3.9)
3-5 years
2 (2009-2011) 515 84.50 - <LOD <LOD 1.9 (<LOD-2.2) 2.9 (1.9-3.9)
3 (2012-2013) 499 81.80 - <LOD <LOD 2.5Footnote E (<LOD-3.7) 4.3Footnote E (2.6-6.1)
4 (2014-2015) 512 80.47 - <LOD <LOD 2.1 (1.8-2.5) 3.0Footnote E (1.8-4.2)
6-11 years
2 (2009-2011) 509 78.86 - <LOD <LOD 1.6Footnote E (<LOD-2.2) 2.2Footnote E (1.2-3.1)
3 (2012-2013) 506 76.09 - <LOD <LOD 1.7 (1.1-2.2) 2.5Footnote E (1.3-3.6)
4 (2014-2015) 513 75.88 - <LOD <LOD 1.6 (1.2-2.0) 2.2Footnote E (0.77-3.7)
12-19 years
2 (2009-2011) 508 72.35 - <LOD <LOD 1.4Footnote E (0.85-2.0) 2.9Footnote E (1.4-4.5)
3 (2012-2013) 510 68.43 - <LOD <LOD 1.4Footnote E (<LOD-2.0) 1.9Footnote E (1.0-2.8)
4 (2014-2015) 506 62.25 - <LOD <LOD 1.4 (1.0-1.8) 2.0Footnote E (1.2-2.8)
20-39 years
2 (2009-2011) 353 69.86 - <LOD <LOD 1.9Footnote E (<LOD-3.0) 2.6Footnote E (<LOD-4.3)
3 (2012-2013) 355 70.70 - <LOD <LOD Footnote F Footnote F
4 (2014-2015) 362 62.71 - <LOD <LOD 1.6 (1.0-2.1) 2.1Footnote E (1.2-3.0)
40-59 years
2 (2009-2011) 354 70.51 - <LOD <LOD 1.9 (1.3-2.6) 2.0Footnote E (1.2-2.8)
3 (2012-2013) 312 70.19 - <LOD <LOD Footnote F Footnote F
4 (2014-2015) 312 70.83 - <LOD <LOD 1.4 (0.93-1.9) Footnote F
60-79 years
2 (2009-2011) 288 73.01 - <LOD <LOD 2.3Footnote E (1.2-3.3) Footnote F
3 (2012-2013) 352 74.43 - <LOD <LOD 2.3Footnote E (0.79-3.8) 3.7Footnote E (1.7-5.6)
4 (2014-2015) 361 68.70 - <LOD <LOD 1.7 (1.3-2.0) 2.6Footnote E (<LOD-4.0)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.7 - Arsenocholine - Geometric means and selected percentiles of urine concentrations (μg As/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
3 (2012-2013) 2536 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 2566 100 - <LOD <LOD <LOD <LOD
Males, 3-79 years
3 (2012-2013) 1251 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1275 100 - <LOD <LOD <LOD <LOD
Females, 3-79 years
3 (2012-2013) 1285 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1291 100 - <LOD <LOD <LOD <LOD
3-5 years
3 (2012-2013) 500 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 512 100 - <LOD <LOD <LOD <LOD
6-11 years
3 (2012-2013) 507 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 514 100 - <LOD <LOD <LOD <LOD
12-19 years
3 (2012-2013) 510 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 506 100 - <LOD <LOD <LOD <LOD
20-39 years
3 (2012-2013) 355 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 362 100 - <LOD <LOD <LOD <LOD
40-59 years
3 (2012-2013) 312 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 311 100 - <LOD <LOD <LOD <LOD
60-79 years
3 (2012-2013) 352 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 361 100 - <LOD <LOD <LOD <LOD

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

Table 10.1.8 - Arsenocholine (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg As/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
3 (2012-2013) 2535 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 2565 100 - <LOD <LOD <LOD <LOD
Males, 3-79 years
3 (2012-2013) 1251 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1274 100 - <LOD <LOD <LOD <LOD
Females, 3-79 years
3 (2012-2013) 1284 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 1291 100 - <LOD <LOD <LOD <LOD
3-5 years
3 (2012-2013) 499 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 512 100 - <LOD <LOD <LOD <LOD
6-11 years
3 (2012-2013) 507 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 513 100 - <LOD <LOD <LOD <LOD
12-19 years
3 (2012-2013) 510 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 506 100 - <LOD <LOD <LOD <LOD
20-39 years
3 (2012-2013) 355 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 362 100 - <LOD <LOD <LOD <LOD
40-59 years
3 (2012-2013) 312 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 311 100 - <LOD <LOD <LOD <LOD
60-79 years
3 (2012-2013) 352 100 - <LOD <LOD <LOD <LOD
4 (2014-2015) 361 100 - <LOD <LOD <LOD <LOD

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

Table 10.1.9 - Arsenocholine and arsenobetaine - Geometric means and selected percentiles of urine concentrations (μg As/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2538 48.50 - <LOD 1.4Footnote E (<LOD-2.2) 28Footnote E (18-39) 48Footnote E (30-67)
3 (2012-2013) 2536 48.15 - <LOD 1.4Footnote E (<LOD-2.1) 24Footnote E (11-36) 56 (37-75)
4 (2014-2015) 2564 47.85 - <LOD 1.2Footnote E (<LOD-1.7) 28Footnote E (13-44) 49 (33-65)
Males, 3-79 years
2 (2009-2011) 1271 46.34 - <LOD 1.5Footnote E (<LOD-2.5) 29Footnote E (14-43) Footnote F
3 (2012-2013) 1251 47.40 - <LOD 1.4Footnote E (<LOD-2.0) 21Footnote E (13-29) 38 (25-51)
4 (2014-2015) 1273 47.68 - <LOD 1.6Footnote E (<LOD-2.6) 33Footnote E (12-54) 44 (30-59)
Females, 3-79 years
2 (2009-2011) 1267 50.67 - <LOD <LOD 28Footnote E (15-41) 49Footnote E (29-69)
3 (2012-2013) 1285 48.87 - <LOD 1.5Footnote E (<LOD-2.6) Footnote F 58Footnote E (33-83)
4 (2014-2015) 1291 48.02 - <LOD Footnote F Footnote F 52Footnote E (18-86)
3-5 years
2 (2009-2011) 516 59.69 - <LOD <LOD Footnote F 34Footnote E (19-49)
3 (2012-2013) 500 57.40 - <LOD <LOD 12Footnote E (6.3-17) Footnote F
4 (2014-2015) 512 59.96 - <LOD <LOD 16Footnote E (5.4-26) Footnote F
6-11 years
2 (2009-2011) 511 58.12 - <LOD <LOD Footnote F Footnote F
3 (2012-2013) 507 59.57 - <LOD <LOD Footnote F 27Footnote E (14-39)
4 (2014-2015) 512 59.77 - <LOD <LOD 15Footnote E (5.2-25) 39Footnote E (13-64)
12-19 years
2 (2009-2011) 510 57.65 - <LOD <LOD 12Footnote E (4.5-19) 38Footnote E (16-59)
3 (2012-2013) 510 51.18 - <LOD <LOD 16Footnote E (7.2-24) 37Footnote E (17-56)
4 (2014-2015) 506 49.80 - <LOD 0.75Footnote E (<LOD-1.2) 16Footnote E (9.4-22) 26Footnote E (13-39)
20-39 years
2 (2009-2011) 355 38.59 2.3Footnote E (1.5-3.6) <LOD Footnote F 33Footnote E (15-52) 68Footnote E (20-110)
3 (2012-2013) 355 44.51 - <LOD Footnote F 19Footnote E (11-28) 35Footnote E (12-58)
4 (2014-2015) 361 37.12 1.9 (1.5-2.5) <LOD 1.5Footnote E (<LOD-2.4) 32Footnote E (17-47) 46Footnote E (24-67)
40-59 years
2 (2009-2011) 357 30.81 1.8 (1.4-2.4) <LOD 1.4Footnote E (<LOD-2.5) Footnote F 35Footnote E (19-52)
3 (2012-2013) 312 34.29 2.2Footnote E (1.3-3.8) <LOD Footnote F Footnote F 57Footnote E (30-84)
4 (2014-2015) 312 38.14 1.8 (1.3-2.6) <LOD 1.3Footnote E (<LOD-1.9) Footnote F 37Footnote E (18-56)
60-79 years
2 (2009-2011) 289 29.41 3.6Footnote E (2.2-5.9) <LOD 3.6Footnote E (1.4-5.8) 40Footnote E (21-59) 74Footnote E (33-120)
3 (2012-2013) 352 30.11 2.6Footnote E (1.8-3.8) <LOD 2.1Footnote E (0.86-3.4) Footnote F 67Footnote E (29-100)
4 (2014-2015) 361 30.19 2.8Footnote E (1.7-4.7) <LOD 2.5Footnote E (0.91-4.0) Footnote F 88Footnote E (49-130)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.10 - Arsenocholine and arsenobetaine (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg As/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2528 48.50 - <LOD 1.5Footnote E (<LOD-2.5) 22 (16-28) 44Footnote E (18-71)
3 (2012-2013) 2535 48.15 - <LOD 1.6 (<LOD-2.1) 25Footnote E (12-39) 44Footnote E (24-63)
4 (2014-2015) 2563 47.85 - <LOD 1.2 (<LOD-1.5) 23Footnote E (12-34) 46Footnote E (27-65)
Males, 3-79 years
2 (2009-2011) 1267 46.34 - <LOD Footnote F 18Footnote E (9.4-27) Footnote F
3 (2012-2013) 1251 47.40 - <LOD 1.2 (<LOD-1.6) 16Footnote E (7.3-24) 34 (25-43)
4 (2014-2015) 1272 47.68 - <LOD 1.3Footnote E (<LOD-1.8) 20Footnote E (9.8-30) 37Footnote E (19-55)
Females, 3-79 years
2 (2009-2011) 1261 50.67 - <LOD <LOD 25 (19-32) 61Footnote E (20-100)
3 (2012-2013) 1284 48.87 - <LOD 2.1Footnote E (<LOD-3.3) 33Footnote E (9.5-56) Footnote F
4 (2014-2015) 1291 48.02 - <LOD 1.1 (<LOD-1.4) Footnote F 62Footnote E (36-89)
3-5 years
2 (2009-2011) 515 59.69 - <LOD <LOD Footnote F Footnote F
3 (2012-2013) 499 57.40 - <LOD <LOD 21Footnote E (11-31) Footnote F
4 (2014-2015) 512 59.96 - <LOD <LOD 26Footnote E (14-38) 57Footnote E (15-98)
6-11 years
2 (2009-2011) 509 58.12 - <LOD <LOD Footnote F Footnote F
3 (2012-2013) 507 59.57 - <LOD <LOD Footnote F 40Footnote E (12-69)
4 (2014-2015) 511 59.77 - <LOD <LOD 17Footnote E (8.4-27) Footnote F
12-19 years
2 (2009-2011) 508 57.65 - <LOD <LOD 9.3Footnote E (4.0-15) 24Footnote E (10-38)
3 (2012-2013) 510 51.18 - <LOD <LOD 10Footnote E (3.8-17) Footnote F
4 (2014-2015) 506 49.80 - <LOD 0.72Footnote E (<LOD-1.0) 9.9Footnote E (5.4-14) Footnote F
20-39 years
2 (2009-2011) 353 38.59 1.9Footnote E (1.2-2.8) <LOD Footnote F 22Footnote E (7.8-37) Footnote F
3 (2012-2013) 355 44.51 - <LOD 1.4Footnote E (<LOD-1.9) 12Footnote E (5.5-19) 21Footnote E (9.8-32)
4 (2014-2015) 361 37.12 1.6 (1.2-2.1) <LOD 1.1Footnote E (<LOD-1.6) 20 (13-27) 29Footnote E (7.7-50)
40-59 years
2 (2009-2011) 355 30.81 1.8 (1.3-2.5) <LOD 1.9Footnote E (<LOD-3.1) 17Footnote E (10-24) 24Footnote E (9.8-39)
3 (2012-2013) 312 34.29 2.6Footnote E (1.6-4.4) <LOD Footnote F 33Footnote E (14-52) Footnote F
4 (2014-2015) 312 38.14 1.7 (1.2-2.4) <LOD 1.1Footnote E (<LOD-1.5) Footnote F Footnote F
60-79 years
2 (2009-2011) 288 29.41 4.2Footnote E (2.6-6.8) <LOD 4.6Footnote E (1.7-7.5) 47Footnote E (13-80) 84Footnote E (43-120)
3 (2012-2013) 352 30.11 2.9Footnote E (1.9-4.4) <LOD Footnote F 35Footnote E (<LOD-57) Footnote F
4 (2014-2015) 361 30.19 2.8Footnote E (1.7-4.4) <LOD 2.2Footnote E (0.93-3.5) Footnote F Footnote F

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.11 - Dimethylarsinic acid (DMA) - Geometric means and selected percentiles of urine concentrations (μg As/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2538 3.78 3.5 (3.0-4.0) 0.93 (0.89-0.97) 3.6 (3.1-4.1) 11 (8.3-13) 16Footnote E (6.6-25)
3 (2012-2013) 2536 3.86 3.6 (3.2-4.0) 1.1 (0.89-1.4) 3.4 (3.0-3.8) 11 (7.8-13) 16Footnote E (7.4-25)
4 (2014-2015) 2567 2.65 3.5 (3.1-3.9) 1.1 (1.0-1.3) 3.4 (3.0-3.8) 10 (8.2-12) 15 (11-20)
Males, 3-79 years
2 (2009-2011) 1271 3.15 3.6 (3.1-4.3) 0.95 (<LOD-1.3) 3.7 (2.8-4.5) 11 (7.9-14) 16Footnote E (7.7-24)
3 (2012-2013) 1251 2.96 3.8 (3.3-4.4) 1.3Footnote E (0.75-1.8) 3.8 (3.3-4.3) 9.8 (7.8-12) 14Footnote E (4.8-23)
4 (2014-2015) 1275 2.27 3.6 (3.1-4.3) 1.1 (0.81-1.3) 3.6 (3.0-4.3) 11 (8.2-14) 19Footnote E (9.8-28)
Females, 3-79 years
2 (2009-2011) 1267 4.42 3.3 (2.8-3.9) 0.92 (0.75-1.1) 3.5 (3.0-3.9) 11 (7.5-14) 18Footnote E (7.3-29)
3 (2012-2013) 1285 4.75 3.4 (2.9-4.1) 1.0 (0.85-1.2) 3.1 (2.7-3.5) 12 (8.4-16) Footnote F
4 (2014-2015) 1292 3.02 3.4 (3.0-3.9) 1.2 (1.1-1.4) 3.3 (2.9-3.7) 9.8 (7.7-12) 13 (9.0-17)
3-5 years
2 (2009-2011) 516 3.68 3.6 (3.1-4.3) 1.4Footnote E (0.89-1.9) 3.5 (3.0-4.0) 9.4 (6.9-12) 13Footnote E (8.5-18)
3 (2012-2013) 500 3.00 3.3 (3.0-3.8) 1.1 (0.83-1.4) 3.4 (2.8-3.9) 10 (7.9-12) 16Footnote E (9.9-21)
4 (2014-2015) 512 2.34 3.4 (3.0-4.0) 1.2 (0.94-1.4) 3.4 (3.0-3.9) 9.2 (7.3-11) 13 (9.1-16)
6-11 years
2 (2009-2011) 511 2.74 3.9 (3.5-4.4) 1.5 (1.0-1.9) 4.1 (3.5-4.7) 9.8 (8.4-11) 14Footnote E (7.7-20)
3 (2012-2013) 507 2.76 3.6 (3.1-4.1) 1.1Footnote E (<LOD-1.6) 3.7 (3.0-4.4) 9.1 (6.6-12) 14Footnote E (6.9-22)
4 (2014-2015) 514 2.14 3.8 (3.2-4.5) 1.3 (0.89-1.7) 3.9 (3.3-4.5) 10 (6.4-14) 16Footnote E (5.7-26)
12-19 years
2 (2009-2011) 510 2.75 3.6 (2.9-4.6) 0.94Footnote E (<LOD-1.5) 3.5 (2.5-4.4) 11 (7.5-14) 17Footnote E (9.3-25)
3 (2012-2013) 510 3.53 3.6 (3.0-4.3) 1.3 (0.88-1.7) 3.4 (2.6-4.2) 9.9 (6.6-13) Footnote F
4 (2014-2015) 506 1.38 3.6 (3.0-4.3) 1.2Footnote E (0.77-1.7) 3.3 (2.8-3.9) 10 (7.9-13) 13 (8.6-18)
20-39 years
2 (2009-2011) 355 5.63 3.6 (2.9-4.5) 0.92 (0.72-1.1) 3.9 (3.0-4.8) Footnote F 22Footnote E (11-33)
3 (2012-2013) 355 4.79 3.8 (3.3-4.5) 1.2Footnote E (<LOD-1.9) 3.5 (2.9-4.1) 12Footnote E (4.4-20) 24Footnote E (8.5-40)
4 (2014-2015) 362 3.31 3.6 (3.1-4.1) 1.1 (<LOD-1.4) 3.4 (2.7-4.0) 9.9 (8.4-11) 12 (9.3-15)
40-59 years
2 (2009-2011) 357 5.32 3.2 (2.6-3.8) 0.91Footnote E (<LOD-1.2) 3.1 (2.5-3.8) 9.0 (7.4-11) 12 (8.8-15)
3 (2012-2013) 312 6.09 3.5 (2.8-4.4) 1.1 (0.77-1.5) 3.4 (2.7-4.1) 12Footnote E (6.0-17) Footnote F
4 (2014-2015) 312 4.17 3.3 (2.8-4.0) 1.1 (0.89-1.3) 3.1 (2.4-3.8) 10Footnote E (4.7-16) 18Footnote E (8.6-27)
60-79 years
2 (2009-2011) 289 3.46 3.6 (2.8-4.5) 0.92 (0.82-1.0) 3.6 (2.9-4.3) 13Footnote E (5.8-20) 21Footnote E (6.5-35)
3 (2012-2013) 352 4.26 3.5 (3.0-4.2) 1.0 (0.86-1.2) 3.4 (2.6-4.2) 10 (7.4-13) 18Footnote E (10-26)
4 (2014-2015) 361 3.60 3.6 (2.9-4.5) 1.2 (0.87-1.5) 3.6 (2.7-4.6) 11 (7.5-14) 14Footnote E (5.3-23)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.12 - Dimethylarsinic acid (DMA) (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg As/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2528 3.78 3.5 (3.0-4.0) 1.4 (1.2-1.6) 3.0 (2.6-3.4) 9.5 (7.1-12) 15Footnote E (9.1-21)
3 (2012-2013) 2535 3.86 3.7 (3.2-4.3) 1.4 (1.3-1.5) 3.4 (3.0-3.8) 11Footnote E (5.6-16) 20Footnote E (11-30)
4 (2014-2015) 2566 2.65 3.2 (2.8-3.6) 1.3 (1.1-1.4) 2.8 (2.5-3.2) 9.1 (6.7-12) 13 (10-16)
Males, 3-79 years
2 (2009-2011) 1267 3.15 3.1 (2.7-3.6) 1.3 (<LOD-1.5) 2.9 (2.5-3.3) 7.7 (5.3-10) 10Footnote E (4.4-16)
3 (2012-2013) 1251 2.96 3.1 (2.8-3.6) 1.3 (1.1-1.4) 3.0 (2.4-3.5) 7.2 (5.4-9.1) 13Footnote E (7.1-19)
4 (2014-2015) 1274 2.27 2.9 (2.5-3.4) 1.1 (0.93-1.3) 2.5 (2.1-2.9) 8.4 (6.3-11) 12 (8.4-15)
Females, 3-79 years
2 (2009-2011) 1261 4.42 3.9 (3.3-4.5) 1.6 (1.3-1.8) 3.3 (2.8-3.9) 11Footnote E (5.9-16) 18Footnote E (11-24)
3 (2012-2013) 1284 4.75 4.3 (3.6-5.3) 1.5 (1.3-1.7) 3.8 (3.1-4.4) 15Footnote E (5.2-25) 24Footnote E (15-33)
4 (2014-2015) 1292 3.02 3.5 (3.0-4.1) 1.4 (1.1-1.7) 3.0 (2.4-3.5) 10 (7.4-13) 15 (11-19)
3-5 years
2 (2009-2011) 515 3.68 6.4 (5.6-7.3) 3.0 (2.7-3.3) 5.6 (4.7-6.5) 16 (11-20) 23Footnote E (10-36)
3 (2012-2013) 499 3.00 6.5 (5.9-7.1) 2.8 (2.1-3.4) 6.1 (5.5-6.8) 14 (11-17) 24Footnote E (13-36)
4 (2014-2015) 512 2.34 6.0 (5.4-6.6) 2.7 (2.3-3.1) 5.3 (4.8-5.8) 15 (11-18) 21Footnote E (12-30)
6-11 years
2 (2009-2011) 509 2.74 4.5 (4.1-5.0) 2.1 (1.9-2.3) 4.2 (3.8-4.7) 11 (7.9-13) 17Footnote E (10-24)
3 (2012-2013) 507 2.76 4.5 (3.9-5.2) 2.2 (<LOD-2.4) 4.1 (3.7-4.4) 9.9 (6.7-13) 14Footnote E (7.2-21)
4 (2014-2015) 513 2.14 4.2 (3.7-4.8) 1.9 (1.6-2.2) 3.7 (3.3-4.2) 11 (7.6-14) 14Footnote E (7.7-21)
12-19 years
2 (2009-2011) 508 2.75 2.8 (2.3-3.5) 1.1 (<LOD-1.4) 2.4 (1.9-3.0) 8.5Footnote E (4.5-13) 13Footnote E (7.6-19)
3 (2012-2013) 510 3.53 2.7 (2.2-3.4) 1.2 (1.1-1.4) 2.3 (1.7-2.9) 7.4Footnote E (2.9-12) 12Footnote E (5.9-17)
4 (2014-2015) 506 1.38 2.6 (2.3-3.1) 1.1 (0.92-1.3) 2.4 (2.0-2.8) 7.3 (4.7-9.9) 10 (6.8-13)
20-39 years
2 (2009-2011) 353 5.63 3.1 (2.5-3.9) 1.3 (0.97-1.6) 2.6 (1.9-3.3) 9.1Footnote E (5.8-12) 14Footnote E (7.2-21)
3 (2012-2013) 355 4.79 2.9 (2.6-3.3) 1.1Footnote E (<LOD-1.6) 2.7 (2.3-3.0) Footnote F 17Footnote E (4.7-29)
4 (2014-2015) 362 3.31 2.9 (2.5-3.4) 1.2 (<LOD-1.4) 2.5 (2.0-3.0) 8.4 (6.4-10) 11Footnote E (6.4-15)
40-59 years
2 (2009-2011) 355 5.32 3.3 (2.9-3.7) 1.6 (<LOD-1.8) 3.0 (2.7-3.2) 7.7 (5.5-9.9) 11Footnote E (6.1-15)
3 (2012-2013) 312 6.09 4.1 (3.3-5.2) 1.5 (1.2-1.7) 3.8 (3.1-4.5) Footnote F 24Footnote E (<LOD-40)
4 (2014-2015) 312 4.17 3.1 (2.5-3.7) 1.2 (1.0-1.4) 2.9 (2.3-3.5) 8.5Footnote E (3.3-14) 15Footnote E (7.1-22)
60-79 years
2 (2009-2011) 288 3.46 4.2 (3.4-5.3) 1.5Footnote E (0.88-2.1) 4.1 (3.1-5.0) Footnote F Footnote F
3 (2012-2013) 352 4.26 4.0 (3.2-4.9) 1.5 (1.2-1.9) 3.6 (2.9-4.3) 11Footnote E (4.6-18) 20Footnote E (10-30)
4 (2014-2015) 361 3.60 3.5 (2.9-4.2) 1.4 (1.1-1.7) 2.9 (2.0-3.8) 11 (7.2-14) 14Footnote E (7.3-20)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

Table 10.1.13 - Monomethylarsonic acid (MMA) - Geometric means and selected percentiles of urine concentrations (μg As/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2538 73.01 - <LOD <LOD 1.2 (1.0-1.4) 1.6 (1.1-2.0)
3 (2012-2013) 2536 71.53 - <LOD <LOD 1.2 (1.1-1.4) 1.5 (1.3-1.7)
4 (2014-2015) 2567 71.25 - <LOD <LOD 1.2 (1.0-1.4) 1.6 (1.3-1.9)
Males, 3-79 years
2 (2009-2011) 1271 69.63 - <LOD <LOD 1.3 (0.92-1.6) 1.8 (1.3-2.4)
3 (2012-2013) 1251 68.35 - <LOD <LOD 1.2 (1.0-1.4) 1.5 (1.3-1.7)
4 (2014-2015) 1275 69.65 - <LOD <LOD 1.3 (1.1-1.6) 1.7 (1.3-2.1)
Females, 3-79 years
2 (2009-2011) 1267 76.40 - <LOD <LOD 1.1 (0.84-1.3) 1.3 (1.0-1.5)
3 (2012-2013) 1285 74.63 - <LOD <LOD 1.2 (0.88-1.5) 1.5 (1.3-1.8)
4 (2014-2015) 1292 72.83 - <LOD <LOD 1.1 (0.89-1.3) 1.5 (1.1-1.9)
3-5 years
2 (2009-2011) 516 77.91 - <LOD <LOD 0.98 (0.79-1.2) 1.3 (1.1-1.5)
3 (2012-2013) 500 79.20 - <LOD <LOD 0.91 (<LOD-1.2) 1.5 (1.1-1.9)
4 (2014-2015) 512 79.10 - <LOD <LOD 0.89 (0.81-0.98) 1.1 (0.94-1.3)
6-11 years
2 (2009-2011) 511 76.52 - <LOD <LOD 0.97Footnote E (<LOD-1.3) 1.6 (1.1-2.1)
3 (2012-2013) 507 72.58 - <LOD <LOD 1.0 (0.84-1.2) 1.3 (1.1-1.4)
4 (2014-2015) 514 72.57 - <LOD <LOD 1.2 (0.89-1.4) 1.5 (1.2-1.8)
12-19 years
2 (2009-2011) 510 62.94 - <LOD <LOD 1.3 (0.97-1.6) 1.7 (1.2-2.2)
3 (2012-2013) 510 62.16 - <LOD <LOD 1.3 (1.1-1.6) 1.6 (1.3-1.8)
4 (2014-2015) 506 57.71 - <LOD <LOD 1.3 (0.88-1.8) 1.8 (1.3-2.4)
20-39 years
2 (2009-2011) 355 70.14 - <LOD <LOD 1.2 (0.89-1.6) 1.7Footnote E (0.94-2.5)
3 (2012-2013) 355 66.48 - <LOD <LOD 1.3 (1.0-1.5) 1.5 (1.3-1.7)
4 (2014-2015) 362 63.54 - <LOD <LOD 1.3 (1.1-1.6) 1.6 (1.3-1.9)
40-59 years
2 (2009-2011) 357 71.43 - <LOD <LOD 1.2 (0.92-1.5) 1.4Footnote E (0.87-1.9)
3 (2012-2013) 312 72.76 - <LOD <LOD 1.1 (0.84-1.4) 1.6 (1.1-2.2)
4 (2014-2015) 312 74.36 - <LOD <LOD 1.2Footnote E (<LOD-1.7) 1.9Footnote E (<LOD-3.0)
60-79 years
2 (2009-2011) 289 81.31 - <LOD <LOD 1.0 (0.70-1.3) 1.4Footnote E (0.73-2.0)
3 (2012-2013) 352 76.70 - <LOD <LOD 1.1 (0.79-1.5) 1.4 (1.2-1.6)
4 (2014-2015) 361 82.27 - <LOD <LOD 1.1 (0.84-1.3) 1.3 (0.99-1.6)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

Table 10.1.14 - Monomethylarsonic acid (MMA) (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg As/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2528 73.01 - <LOD <LOD 1.3Footnote E (0.75-1.8) 2.0 (1.8-2.1)
3 (2012-2013) 2535 71.53 - <LOD <LOD 1.2 (1.1-1.4) 1.7 (1.5-1.9)
4 (2014-2015) 2566 71.25 - <LOD <LOD 1.2 (0.97-1.3) 1.4 (1.2-1.7)
Males, 3-79 years
2 (2009-2011) 1267 69.63 - <LOD <LOD 1.0 (0.87-1.1) 1.6Footnote E (1.0-2.2)
3 (2012-2013) 1251 68.35 - <LOD <LOD 1.0 (0.87-1.1) 1.3 (1.0-1.6)
4 (2014-2015) 1274 69.65 - <LOD <LOD 1.0 (0.91-1.2) 1.3 (1.0-1.6)
Females, 3-79 years
2 (2009-2011) 1261 76.40 - <LOD <LOD 1.9 (1.4-2.4) 2.0 (1.4-2.5)
3 (2012-2013) 1284 74.63 - <LOD <LOD 1.6 (1.3-1.9) 2.1 (1.8-2.5)
4 (2014-2015) 1292 72.83 - <LOD <LOD 1.3 (0.97-1.6) 1.7 (1.2-2.2)
3-5 years
2 (2009-2011) 515 77.91 - <LOD <LOD 1.9 (1.8-2.0) 2.7 (1.8-3.6)
3 (2012-2013) 499 79.20 - <LOD <LOD 2.0 (<LOD-2.5) 3.0 (2.0-4.0)
4 (2014-2015) 512 79.10 - <LOD <LOD 1.8 (1.3-2.2) 2.2 (1.9-2.5)
6-11 years
2 (2009-2011) 509 76.52 - <LOD <LOD 1.2 (<LOD-1.6) 1.9 (1.7-2.1)
3 (2012-2013) 507 72.58 - <LOD <LOD 1.3 (1.1-1.5) 1.8 (1.5-2.0)
4 (2014-2015) 513 72.57 - <LOD <LOD 1.2 (1.0-1.3) 1.4 (1.2-1.5)
12-19 years
2 (2009-2011) 508 62.94 - <LOD <LOD 0.99 (0.84-1.1) 1.3Footnote E (0.74-1.9)
3 (2012-2013) 510 62.16 - <LOD <LOD 0.99 (0.75-1.2) 1.5 (1.0-2.0)
4 (2014-2015) 506 57.71 - <LOD <LOD 0.98 (0.82-1.1) 1.1 (0.87-1.4)
20-39 years
2 (2009-2011) 353 70.14 - <LOD <LOD Footnote F 1.8Footnote E (0.89-2.8)
3 (2012-2013) 355 66.48 - <LOD <LOD 0.97 (0.73-1.2) 1.3 (0.87-1.8)
4 (2014-2015) 362 63.54 - <LOD <LOD 1.1 (0.96-1.2) Footnote F
40-59 years
2 (2009-2011) 355 71.43 - <LOD <LOD 1.2Footnote E (0.55-1.8) 1.9 (1.4-2.4)
3 (2012-2013) 312 72.76 - <LOD <LOD 1.3 (0.92-1.6) 1.7 (1.3-2.0)
4 (2014-2015) 312 74.36 - <LOD <LOD 1.3 (<LOD-1.7) 1.5 (<LOD-1.9)
60-79 years
2 (2009-2011) 288 81.31 - <LOD <LOD 1.7 (1.3-2.2) 1.9 (1.6-2.2)
3 (2012-2013) 352 76.70 - <LOD <LOD 1.4Footnote E (0.87-1.9) 2.1Footnote E (1.3-2.9)
4 (2014-2015) 361 82.27 - <LOD <LOD 1.0 (0.75-1.3) 1.3 (1.1-1.6)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

10.2 Cadmium

Cadmium (CASRN 7440-43-9) is among the least abundant metals in the Earth's crust at an average concentration of approximately 0.00001% (Emsley, 2001). It is a naturally occurring soft, silvery white, blue-tinged metal. Cadmium often occurs in zinc ores (Health Canada, 1986a). Common forms include soluble and insoluble species that may also be found as particulate matter in the atmosphere (ATSDR, 2012b; CCME, 1999a).

Cadmium is released to the environment as a result of natural processes, including forest fires, volcanic emissions, and weathering of soil and bedrock (Morrow, 2000). The main anthropogenic sources of atmospheric cadmium are industrial base-metal smelting and refining processes, and combustion processes such as coal-fired electrical plants and waste incineration where cadmium is released as a by-product (CCME, 1999a).

Cadmium is primarily used in the manufacture of nickel-cadmium batteries (USGS, 2012). It is also used in industrial coatings and electroplating, in pigments, and as a stabilizer in polyvinyl chloride plastics. Cadmium is present in metal alloy sheets, wires, rods, solders, and shields for various industrial applications (Environment Canada and Health Canada, 1994a). It is also sometimes used in costume jewellery and as a pigment in ceramic glazes. Cadmium may also be present in fertilizers as the result of recycling of by-products and waste materials for land application. It is frequently an impurity in galvanized pipes and as a constituent of solders used in plumbing and distributions systems and can leach into drinking water (Health Canada, 1986a; WHO, 2011c).

In smokers, inhalation of cigarette smoke is a major source of cadmium exposure (Environment Canada and Health Canada, 1994a; IARC, 2012a). For non-smoking adults and children, the largest source of cadmium exposure is through the ingestion of food (Environment Canada and Health Canada, 1994a; IARC, 2012a). Ambient air is a minor source of exposure with intakes estimated to be two to three orders of magnitude lower than food, although cadmium compounds are more readily absorbed following inhalation than ingestion (Friberg, 1985). Other potential sources of exposure include ingestion of drinking water, soil, or dust (ATSDR, 2012b; Environment Canada and Health Canada, 1994a; Rasmussen et al., 2013).

Absorption of dietary cadmium into the bloodstream depends on one's nutritional status and the levels of other components of the diet such as iron, calcium, and protein. The average gastrointestinal absorption of dietary cadmium is estimated at 5% in adult men and 10% or higher in women (CDC, 2009). About 25% to 60% of inhaled cadmium is absorbed through the lungs (ATSDR, 2012b). Absorbed cadmium accumulates mainly in the kidney and liver, with approximately one-third to one-half of the total body burden accumulating in the kidney (CDC, 2009). The biological half-life of cadmium in the kidney has been estimated to be approximately 10 to 12 years (Amzal et al., 2009; Lauwerys et al., 1994). Only a small proportion of absorbed cadmium is eliminated, mainly in the urine and feces with small amounts also eliminated through hair, nails, and sweat.

Cadmium can be measured in blood, urine, feces, liver, kidney, and hair among other tissues. Cadmium concentrations in urine best reflect cumulative exposure and the concentration of cadmium in the kidney, although slight fluctuations occur with recent exposures (Adams and Newcomb, 2014). Concentrations in blood reflect more recent exposures (Adams and Newcomb, 2014). Blood cadmium concentrations are about twice as high in smokers compared with non-smokers; concentrations can also be elevated following occupational exposures (ATSDR, 2012b).

Oral exposure to high doses of cadmium may cause severe gastrointestinal irritation and kidney effects (ATSDR, 2012b). Chronic exposure via inhalation has been associated with effects in the lungs, including emphysema, and in the kidneys (ATSDR, 2012b). The kidney is considered the critical organ that exhibits the first adverse effects following both oral and inhalation exposure (EFSA, 2009; FAO/WHO, 2011c).

Cadmium and its compounds have been classified as probably carcinogenic to humans by inhalation by Environment Canada and Health Canada (Environment Canada and Health Canada, 1994a). More recently, the International Agency for Research on Cancer has classified cadmium and its compounds as carcinogenic to humans (Group 1) based on various data, including associations between occupational inhalation exposure and lung cancer (IARC, 2012a). There is insufficient evidence to determine whether or not cadmium is carcinogenic following oral exposure (ATSDR, 2012b).

Health Canada and Environment Canada concluded that inorganic cadmium compounds are a concern for human health based on its carcinogenic potential and effects on the kidneys (Environment Canada and Health Canada, 1994a). Inorganic cadmium compounds are listed on Schedule 1, List of Toxic Substances, under the Canadian Environmental Protection Act, 1999 (CEPA 1999). The Act allows the federal government to control the importation, manufacture, distribution, and use of inorganic cadmium compounds in Canada (Canada, 1999; Canada, 2000). Risk management actions under CEPA 1999 have been developed to control releases of cadmium from thermal electric power generation, base-metal smelting, and steel manufacturing processes (Environment Canada, 2013a).

In Canada, the leachable cadmium content in a variety of consumer products is regulated under the Canada Consumer Product Safety Act (Canada, 2010a). Consumer products regulated for leachable cadmium content include glazed ceramics and glassware, as well as paints and other surface coatings on cribs, toys, and other products for use by a child in learning or play situations (Canada, 1998; Canada, 2010b; Canada, 2011b; Health Canada, 2009c). In addition, because children's jewellery items containing high levels of cadmium have been found on the Canadian marketplace, a new guideline limit for total cadmium in children's jewellery was proposed in 2016 as part of the Children's Jewellery Regulations under the Canadian Consumer Product Safety Act (Canada, 2016a). Cadmium and its compounds are included as prohibited ingredients on the List of Prohibited and Restricted Cosmetic Ingredients (more commonly referred to as the Cosmetic Ingredient Hotlist or simply the Hotlist) (Health Canada, 2015b). The Hotlist is an administrative tool that Health Canada uses to communicate to manufacturers and others that certain substances, when present in a cosmetic, may contravene the general prohibition found in section 16 of the Food and Drugs Act or a provision of the Cosmetic Regulations. On the basis of health considerations, Health Canada, in collaboration with the Federal-Provincial-Territorial Committee on Drinking Water, has developed a guideline for Canadian drinking water quality that establishes the maximum acceptable concentration for cadmium in drinking water (Health Canada, 1986a; Health Canada, 2014d). Cadmium is also included in the list of various chemicals analyzed as part of Health Canada's ongoing Total Diet Study surveys (Health Canada, 2013d). The food items analyzed represent those that are most typical of the Canadian diet, and the surveys are used to provide dietary exposure estimates for chemicals that Canadians in different age-sex groups are exposed to through the food supply.

In a biomonitoring study carried out in the region of the city of Québec with 500 participants aged 18-65 years, the geometric means for cadmium in whole blood was 0.69 µg/L (INSPQ, 2004). The First Nations Biomonitoring Initiative (FNBI) is a nationally representative biomonitoring study of adult First Nations peoples living on reserves south of the 60° parallel (AFN, 2013). It comprises 13 randomly selected First Nation communities in Canada with 503 First Nations participants aged 20 years and older. In 2011, the geometric mean and 95th percentile for cadmium in blood were 0.96 µg/L and 4.65 µg/L, respectively. In Northern Canada, the contaminant component of the Inuit Health Survey (2007-2008) has measured the body burden of cadmium for 2,172 Inuit participants from 36 communities in Nunavut, Nunatsiavut, and the Inuvialuit Settlement Region (Laird et al., 2013). The geometric mean blood concentration of cadmium for all participants (18 years and older) was 1.6 µg/L. The Maternal-Infant Research on Environmental Chemicals (MIREC) Study is a national-level prospective biomonitoring study carried out in pregnant women aged 18 years and older from 10 sites across Canada, 2008-2011 (Arbuckle et al., 2013). In the MIREC Study of 1,938 participants in their first trimester of pregnancy, the geometric mean and 95th percentile for cadmium in blood were 0.2197 µg/L and 1.124 µg/L, respectively (Arbuckle et al., 2016).

Cadmium was analyzed in the whole blood of all Canadian Health Measures Survey participants aged 6-79 years in cycle 1 (2007-2009), and 3-79 years in cycle 2 (2009-2011), cycle 3 (2012-2013), and cycle 4 (2014-2015). Data from these cycles are presented in blood as µg/L. Finding a measurable amount of cadmium in blood is an indicator of exposure to cadmium and does not necessarily mean that an adverse health effect will occur.

Table 10.2.1 - Cadmium - Geometric means and selected percentiles of whole blood concentrations (μg/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 1 (2007-2009), cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 6070 5.16 0.29 (0.26-0.32) 0.083 (0.074-0.093) 0.26 (0.24-0.29) 1.7 (1.3-2.0) 2.6 (2.1-3.0)
3 (2012-2013) 5538 11.48 0.33 (0.30-0.36) <LOD 0.27 (0.25-0.29) 2.0 (1.4-2.6) 3.4 (2.5-4.3)
4 (2014-2015) 5497 10.88 0.31 (0.29-0.32) <LOD 0.25 (0.23-0.26) 1.9 (1.5-2.4) 3.3 (2.6-4.0)
Males, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 2940 5.78 0.26 (0.24-0.29) 0.079 (0.070-0.089) 0.23 (0.20-0.26) 1.7 (1.5-2.0) 2.4 (2.0-2.9)
3 (2012-2013) 2769 12.35 0.29 (0.27-0.32) <LOD 0.22 (0.19-0.25) 2.1 (1.5-2.7) 3.3 (2.5-4.2)
4 (2014-2015) 2753 12.42 0.28 (0.27-0.30) <LOD 0.20 (0.19-0.21) 2.0 (1.4-2.6) 3.3 (2.5-4.2)
Females, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 3130 4.57 0.32 (0.28-0.36) 0.089 (0.080-0.098) 0.30 (0.27-0.33) 1.5Footnote E (0.92-2.1) 2.7 (2.1-3.4)
3 (2012-2013) 2769 10.62 0.37 (0.33-0.41) <LOD 0.32 (0.28-0.37) 1.7Footnote E (0.62-2.8) 3.4Footnote E (1.8-5.0)
4 (2014-2015) 2744 9.33 0.33 (0.31-0.35) 0.099 (0.095-0.10) 0.28 (0.25-0.30) 1.8Footnote E (1.1-2.5) 3.1 (2.3-4.0)
3-5 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 495 15.15 0.073 (0.065-0.081) <LOD 0.078 (0.069-0.087) 0.099 (0.098-0.10) Footnote F
3 (2012-2013) 471 43.52 - <LOD 0.091 (<LOD-0.11) 0.16 (0.11-0.20) 0.18Footnote E (<LOD-0.29)
4 (2014-2015) 479 36.95 0.082 (<LOD-0.091) <LOD 0.093 (0.084-0.10) 0.16 (0.14-0.18) 0.19 (0.15-0.24)
6-11 years
1 (2007-2009) 910 9.12 0.091 (0.082-0.10) <LODFootnote E (<LOD-0.053) 0.092 (0.090-0.094) 0.20 (0.18-0.21) 0.22 (0.19-0.26)
2 (2009-2011) 961 14.05 0.083 (0.076-0.090) <LOD 0.090 (0.087-0.094) 0.17Footnote E (0.088-0.25) 0.20 (0.18-0.23)
3 (2012-2013) 944 27.44 0.095 (0.085-0.11) <LOD 0.10 (0.099-0.10) 0.18 (0.16-0.20) 0.21 (0.18-0.24)
4 (2014-2015) 925 26.92 0.094 (0.086-0.10) <LOD 0.10 (0.096-0.10) 0.16 (0.14-0.19) 0.19 (0.17-0.21)
12-19 years
1 (2007-2009) 945 3.92 0.16 (0.13-0.20) 0.066 (0.045-0.086) Footnote F Footnote F Footnote F
2 (2009-2011) 997 5.72 0.13 (0.12-0.15) 0.062 (0.040-0.084) 0.096 (0.095-0.097) 0.48Footnote E (0.27-0.70) 0.82Footnote E (0.45-1.2)
3 (2012-2013) 977 12.49 0.17 (0.15-0.20) <LOD 0.12Footnote E (<LOD-0.17) 0.82Footnote E (0.31-1.3) 1.7Footnote E (0.91-2.4)
4 (2014-2015) 974 12.22 0.14 (0.13-0.15) <LOD 0.12 (0.12-0.13) 0.29 (0.25-0.33) 0.54Footnote E (0.15-0.94)
20-39 years
1 (2007-2009) 1165 1.55 0.34 (0.30-0.38) 0.091 (0.084-0.098) 0.24 (0.21-0.27) 2.6 (2.0-3.1) 3.4 (3.1-3.7)
2 (2009-2011) 1313 2.21 0.28 (0.24-0.34) 0.090 (0.066-0.11) 0.24 (0.20-0.29) 1.7Footnote E (1.0-2.3) 2.7 (2.1-3.2)
3 (2012-2013) 1032 3.68 0.31 (0.24-0.41) 0.10 (0.084-0.12) 0.25 (0.20-0.29) 2.0Footnote E (0.71-3.3) Footnote F
4 (2014-2015) 1074 2.33 0.33 (0.28-0.38) 0.10 (0.090-0.11) 0.22 (0.17-0.26) 2.9 (1.9-3.9) 4.2Footnote E (2.5-5.9)
40-59 years
1 (2007-2009) 1220 0.90 0.48 (0.43-0.54) 0.098Footnote E (0.054-0.14) 0.36 (0.32-0.41) 3.1 (2.3-3.9) 4.2 (3.7-4.7)
2 (2009-2011) 1222 0.98 0.41 (0.37-0.46) 0.095 (0.090-0.10) 0.34 (0.31-0.37) 2.2 (1.5-2.8) 3.1 (2.3-3.8)
3 (2012-2013) 1071 1.12 0.50 (0.43-0.57) 0.11 (0.084-0.13) 0.39 (0.30-0.48) 3.0 (2.3-3.7) 4.6 (3.7-5.5)
4 (2014-2015) 1050 1.81 0.41 (0.37-0.45) 0.12 (0.097-0.15) 0.33 (0.26-0.39) 2.1Footnote E (1.2-3.0) 3.4 (2.3-4.4)
60-79 years
1 (2007-2009) 1079 0.56 0.45 (0.42-0.49) 0.19 (0.18-0.20) 0.39 (0.37-0.41) 1.7 (1.2-2.2) 2.7 (2.2-3.2)
2 (2009-2011) 1082 0.46 0.45 (0.41-0.50) 0.18 (0.13-0.23) 0.40 (0.35-0.44) 1.6 (1.3-2.0) 2.4 (1.9-2.8)
3 (2012-2013) 1043 0 0.48 (0.43-0.54) 0.19 (0.17-0.20) 0.41 (0.35-0.46) 1.5 (1.3-1.8) 2.6 (1.9-3.3)
4 (2014-2015) 995 0.9 0.44 (0.41-0.48) 0.17 (0.16-0.18) 0.37 (0.34-0.40) 1.6 (1.1-2.2) 2.8 (2.0-3.6)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

b Data not available as participants under the age of 6 years were not included in cycle 1 (2007-2009).

E Use data with caution.

F Data is too unreliable to be published.

10.3 Fluoride

Fluorine (CASRN 16984-48-8) is the 13th most abundant element, occurring naturally in the Earth's crust at an average concentration of about 0.09% (ATSDR, 2003a). It is widely distributed and naturally occurring, but it is rarely found in nature because it reacts readily with most organic and inorganic substances. Fluorides are formed when fluorine reacts with metals. Four inorganic fluorides of environmental importance are calcium fluoride (fluorspar and fluorite), sodium fluoride, sulphur hexafluoride, and hydrogen fluoride (Cotton and Wilkinson, 1988; Mackay and Mackay, 1989).

Fluorides are found in rocks, coal, clay, and soil. Gases and particles produced from volcanic eruptions and minerals leached from bedrock release inorganic fluorides into the environment (ATSDR, 2003a; CCME, 2002). In addition to these natural sources, inorganic fluorides are released through human activities such as phosphate fertilizer production, chemical production, and aluminum smelting (Environment Canada and Health Canada, 1993b).

Hydrogen fluoride is one of the most commonly used fluoride compounds; it is a component in the production of refrigerants, herbicides, pharmaceuticals, aluminum, plastics, high-octane gasoline, electrical components, and fluorescent light bulbs (ATSDR, 2003a). In water, hydrogen fluoride becomes hydrofluoric acid, which is used in the metal and glass manufacturing industries (ATSDR, 2003a). Calcium fluoride is used in the production of steel, aluminum, glass, and enamel, and as the raw material for the production of hydrofluoric acid and hydrogen fluoride (CCME, 2002). Fluoride-containing compounds are often added to drinking water and dental products to prevent dental cavities. Toothpastes are the most commonly used dental product that contain fluoride (Health Canada, 2010c). Other fluoride-containing dental products available to consumers include fluoride supplements, fluoride mouth rinses, and dental floss. Fluoride is also used by professionals in some dental filling material, sealants, and fluoride varnishes. Sodium fluoride is also used as a preservative in wood and glues and in the production of glass, enamel, steel, and aluminum (CCME, 2002). Sulphur hexafluoride is used extensively in electrical switch gear such as power circuit breakers, compressed gas transmission lines, and various components in electrical substations (CCME, 2002).

Fluoride compounds are ubiquitous in the environment; however, the major sources of exposure to the general population are water, food, beverages, and dental products (Health Canada, 2010c). Following ingestion of soluble fluoride salts and inhalation of gaseous hydrogen fluoride, fluoride is rapidly and efficiently absorbed (ATSDR, 2003a). Once absorbed, fluoride is rapidly distributed throughout the body via the bloodstream (ATSDR, 2003a). In infants, about 80% to 90% of the total absorbed fluoride is retained in bones and teeth with the level dropping to about 60% in adults (Fawell et al., 2006). The remaining fluoride in adults and infants is excreted through urine (ATSDR, 2003a). The biological half-life of fluoride is on the order of several hours (ATSDR, 2003; NRC, 2006). Urine and blood analyses are the most common tests for fluoride exposure (ATSDR, 2003a).

The primary adverse effects associated with chronic excess fluoride intake are dental and skeletal fluorosis (IOM, 1997). Exposure to excessive levels of fluoride over a very long period of time can lead to skeletal fluorosis characterized by dense bones, joint pain, and limited range of joint movement (ATSDR, 2003a). Dense bones are often more brittle or fragile than normal bones and there is an increased risk of bone fractures in older adults. Dental fluorosis is a dose-response effect caused by fluoride ingestion during tooth formation that becomes apparent upon eruption of the teeth. The effects of dental fluorosis can range from mild discolouration of the tooth surface to severe staining, enamel loss, and pitting (NRC, 2006).

Health Canada found that the weight of evidence from existing scientific data does not support an association between fluoride and increased risks of cancer, and has classified fluoride in Group VI, unclassifiable with respect to carcinogenicity in humans (Health Canada, 2010c). Similarly, the International Agency for Research on Cancer has classified fluorides (inorganic, used in drinking water) as Group 3, not classifiable as to its carcinogenicity to humans (IARC, 1987).

Health Canada and Environment Canada have reviewed and assessed inorganic fluorides under the Canadian Environmental Protection Act, 1999 (CEPA 1999) (Canada, 1999). The screening assessment concluded that levels of inorganic fluorides normally found in the Canadian environment are not considered harmful to human health but are a concern for the environment (Environment Canada and Health Canada, 1993b). Inorganic fluorides are listed on Schedule 1, List of Toxic Substances, under CEPA 1999. The Act allows the federal government to control the importation, manufacture, distribution, and use of inorganic fluorides in Canada (Canada, 1999; Canada, 2000).

Health Canada recommends that fluoride requirements be based on the beneficial effect on dental caries (Health Canada, 2010c). Young children tend to swallow toothpaste during brushing, so guidelines have been established that strive to balance the health risks with the health benefits of fluoride use. In general, toothpaste use is not recommended for children under the age of 3, unless recommended by a health professional. For children 3 to 6 years old, Health Canada recommends supervision during brushing and use of only a small amount of fluoridated toothpaste (Health Canada, 2010d). Fluoride-containing substances are included as restricted ingredients on the List of Prohibited and Restricted Cosmetic Ingredients (more commonly referred to as the Cosmetic Ingredient Hotlist or simply the Hotlist) and are not permitted in oral products (Health Canada, 2015b). The Hotlist is an administrative tool that Health Canada uses to communicate to manufacturers and others that certain substances, when present in a cosmetic, may contravene the general prohibition found in section 16 of the Food and Drugs Act or a provision of the Cosmetic Regulations.

Health Canada completed a review of the health risks associated with fluoride in drinking water in which moderate dental fluorosis was chosen as the endpoint of concern for fluoride (Health Canada, 2010c). Although moderate dental fluorosis is not a health concern and is not considered to be a toxicological endpoint, Health Canada considers it to be an adverse effect based on its potential aesthetic concern. The current guideline for Canadian drinking water quality developed by Health Canada in collaboration with the Federal-Provincial-Territorial Committee on Drinking Water established the maximum acceptable concentration for fluoride in drinking water (Health Canada, 2010c). This guideline is considered to be protective against all potential adverse health effects, including those related to cancer, immunotoxicity, reproductive/developmental toxicity, genotoxicity, and/or neurotoxicity (Health Canada, 2010c). For communities wishing to fluoridate their water supply, Health Canada has determined an optimal concentration of fluoride in drinking water to promote dental health while protecting against adverse effects (Health Canada, 2010d). Tolerable upper intake levels for fluoride that account for its potential toxicity have been developed by the Institute of Medicine and adopted by Health Canada (Health Canada, 2010e; IOM, 1997).

The concentration of fluoride in some foods and prepackaged water and ice is regulated by Health Canada under the Food and Drug Regulations (Canada, 2012c). Food tolerances, or maximum levels, for fluoride currently exist for edible bone meal and fish protein as well as prepackaged ice or water, including those represented as mineral or spring water (Canada, 2012c).

The first cycle (2007-2009) of the Canadian Health Measures Survey (CHMS) included a National Oral Health Component supported by Health Canada (Health Canada, 2010f). In addition to many other dental considerations, dental fluorosis was measured in children ranging from 6 to 12 years old. The results from cycle 1 of the CHMS found that 60% of children had teeth considered normal, 24% had enamel with white flecks or spots where the cause was questionable, 12% had one or more teeth with fluorosis classified as very mild, and 4% had fluorosis classified as mild. The prevalence of moderate or severe fluorosis was too low to allow reporting (less than 0.3%).

Fluoride was analyzed in the urine of CHMS cycle 2 (2009-2011), cycle 3 (2012-2013), and cycle 4 (2014-2015) participants aged 3-79 years, and is presented as both mg/L and mg/g creatinine. Finding a measurable amount of fluoride in urine is an indicator of exposure to fluoride and does not necessarily mean that an adverse health effect will occur.

Table 10.3.1 - Fluoride - Geometric means and selected percentiles of urine concentrations (mg/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2530 0 0.50 (0.46-0.55) 0.19 (0.17-0.22) 0.48 (0.44-0.53) 1.2 (1.0-1.3) 1.5 (1.2-1.7)
3 (2012-2013) 2671 0 0.43 (0.39-0.48) 0.15 (0.14-0.17) 0.44 (0.39-0.49) 1.1 (0.97-1.3) 1.4 (0.99-1.7)
4 (2014-2015) 2574 0 0.47 (0.38-0.59) 0.18 (0.15-0.22) 0.45 (0.33-0.58) 1.2 (0.91-1.4) 1.4 (1.2-1.6)
Males, 3-79 years
2 (2009-2011) 1267 0 0.53 (0.47-0.60) 0.23 (0.20-0.25) 0.51 (0.42-0.60) 1.3 (1.0-1.5) 1.6 (1.4-1.9)
3 (2012-2013) 1320 0 0.44 (0.39-0.49) 0.16 (0.13-0.19) 0.44 (0.39-0.49) 1.1 (0.92-1.3) 1.3Footnote E (0.81-1.8)
4 (2014-2015) 1246 0 0.47 (0.36-0.61) 0.18 (0.13-0.23) 0.45 (0.29-0.60) 1.1 (0.79-1.4) 1.5 (1.1-1.9)
Females, 3-79 years
2 (2009-2011) 1263 0 0.47 (0.43-0.52) 0.17 (0.15-0.20) 0.47 (0.41-0.53) 1.1 (0.92-1.3) 1.3 (1.0-1.6)
3 (2012-2013) 1351 0 0.43 (0.38-0.48) 0.14 (0.11-0.16) 0.45 (0.37-0.53) 1.1 (0.92-1.4) 1.4 (1.0-1.8)
4 (2014-2015) 1328 0 0.48 (0.39-0.58) 0.18 (0.16-0.21) 0.46 (0.35-0.57) 1.2 (0.94-1.5) 1.4 (1.2-1.6)
3-5 years
2 (2009-2011) 510 0 0.47 (0.42-0.52) 0.18 (0.13-0.23) 0.51 (0.44-0.58) 0.99 (0.88-1.1) 1.3 (0.92-1.7)
3 (2012-2013) 493 0 0.39 (0.32-0.48) 0.13 (0.098-0.17) 0.37 (0.25-0.50) 0.99 (0.77-1.2) 1.2 (0.97-1.5)
4 (2014-2015) 483 0 0.42 (0.33-0.54) 0.13Footnote E (0.071-0.19) 0.39 (0.25-0.53) 1.1Footnote E (0.68-1.6) 1.6Footnote E (0.66-2.5)
6-11 years
2 (2009-2011) 514 0 0.50 (0.44-0.57) 0.20 (0.17-0.24) 0.49 (0.42-0.55) 1.1 (0.90-1.3) 1.5 (1.1-1.8)
3 (2012-2013) 549 0 0.40 (0.36-0.45) 0.18 (0.15-0.20) 0.38 (0.35-0.41) 0.85 (0.61-1.1) 1.1 (0.88-1.4)
4 (2014-2015) 533 0 0.47 (0.37-0.60) 0.19 (0.14-0.25) 0.46 (0.34-0.58) 1.1Footnote E (0.55-1.7) 1.6 (1.1-2.0)
12-19 years
2 (2009-2011) 507 0 0.41 (0.37-0.46) 0.17 (0.15-0.19) 0.44 (0.36-0.52) 0.94 (0.82-1.1) 1.2 (0.98-1.3)
3 (2012-2013) 549 0 0.39 (0.35-0.44) 0.16 (0.13-0.20) 0.37 (0.33-0.41) 0.93 (0.71-1.2) 1.1 (0.85-1.3)
4 (2014-2015) 481 0 0.42 (0.35-0.50) 0.17 (0.14-0.20) 0.44 (0.36-0.53) 0.99 (0.75-1.2) 1.1 (0.91-1.2)
20-39 years
2 (2009-2011) 354 0 0.53 (0.47-0.59) 0.23 (0.19-0.27) 0.50 (0.38-0.62) 1.2 (0.96-1.5) 1.4 (1.1-1.8)
3 (2012-2013) 371 0 0.43 (0.35-0.53) 0.15 (0.11-0.19) 0.47 (0.37-0.57) 1.1 (0.77-1.4) 1.3Footnote E (0.58-2.1)
4 (2014-2015) 369 0 0.46 (0.35-0.60) 0.18Footnote E (0.099-0.27) 0.42 (0.29-0.55) 1.2 (0.81-1.6) 1.4 (1.1-1.7)
40-59 years
2 (2009-2011) 357 0 0.51 (0.44-0.61) 0.19 (0.13-0.25) 0.51 (0.40-0.61) 1.2 (0.93-1.6) 1.7 (1.3-2.2)
3 (2012-2013) 359 0 0.46 (0.42-0.50) 0.16 (0.13-0.20) 0.46 (0.41-0.50) 1.2 (1.0-1.3) 1.4 (0.88-1.9)
4 (2014-2015) 368 0 0.49 (0.36-0.66) 0.18 (0.15-0.21) 0.48Footnote E (0.26-0.70) 1.2 (0.90-1.5) 1.4 (1.1-1.7)
60-79 years
2 (2009-2011) 288 0 0.50 (0.44-0.56) 0.19Footnote E (0.11-0.27) 0.48 (0.42-0.54) 1.2 (0.99-1.5) 1.6 (1.3-2.0)
3 (2012-2013) 350 0 0.43 (0.36-0.51) 0.13 (0.086-0.18) 0.45 (0.34-0.56) 1.3 (0.85-1.7) 1.7 (1.3-2.0)
4 (2014-2015) 340 0 0.51 (0.43-0.61) 0.19 (0.15-0.22) 0.49 (0.33-0.64) 1.2 (0.95-1.5) 1.8 (1.2-2.4)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

Table 10.3.2 - Fluoride (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (mg/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
2 (2009-2011) 2520 0 0.50 (0.45-0.55) 0.20 (0.18-0.22) 0.48 (0.41-0.54) 1.2 (0.99-1.4) 1.6 (1.3-2.0)
3 (2012-2013) 2669 0 0.46 (0.41-0.51) 0.18 (0.16-0.21) 0.45 (0.37-0.53) 1.0 (0.88-1.1) 1.4 (1.1-1.7)
4 (2014-2015) 2574 0 0.41 (0.34-0.48) 0.17 (0.14-0.19) 0.40 (0.32-0.48) 0.97 (0.84-1.1) 1.2 (1.0-1.5)
Males, 3-79 years
2 (2009-2011) 1263 0 0.46 (0.40-0.52) 0.20 (0.16-0.24) 0.43 (0.36-0.50) 1.0 (0.85-1.2) 1.2 (0.86-1.6)
3 (2012-2013) 1320 0 0.40 (0.35-0.45) 0.16 (0.12-0.20) 0.41 (0.33-0.48) 0.87 (0.75-0.98) 1.1 (0.90-1.2)
4 (2014-2015) 1246 0 0.35 (0.30-0.42) 0.15 (0.13-0.17) 0.36 (0.27-0.45) 0.75 (0.62-0.89) 0.99 (0.84-1.1)
Females, 3-79 years
2 (2009-2011) 1257 0 0.54 (0.49-0.60) 0.21 (0.18-0.24) 0.52 (0.45-0.60) 1.4 (1.2-1.6) 1.9 (1.5-2.3)
3 (2012-2013) 1349 0 0.53 (0.47-0.59) 0.22 (0.19-0.25) 0.53 (0.43-0.63) 1.2 (0.93-1.4) 1.6 (1.3-2.0)
4 (2014-2015) 1328 0 0.47 (0.39-0.56) 0.19 (0.15-0.23) 0.44 (0.33-0.54) 1.1 (0.90-1.2) 1.6 (1.1-2.1)
3-5 years
2 (2009-2011) 509 0 0.81 (0.73-0.90) 0.40 (0.34-0.46) 0.78 (0.72-0.85) 1.7 (1.3-2.0) 2.8Footnote E (1.7-4.0)
3 (2012-2013) 492 0 0.76 (0.68-0.86) 0.37 (0.30-0.44) 0.73 (0.55-0.90) 1.5 (1.3-1.6) 1.7 (1.4-1.9)
4 (2014-2015) 483 0 0.75 (0.63-0.90) 0.34 (0.27-0.42) 0.68 (0.52-0.85) 1.8 (1.4-2.2) 3.1Footnote E (1.3-4.9)
6-11 years
2 (2009-2011) 512 0 0.58 (0.53-0.63) 0.30 (0.28-0.32) 0.57 (0.50-0.63) 1.2 (0.96-1.4) 1.5 (1.0-2.0)
3 (2012-2013) 549 0 0.50 (0.43-0.57) 0.24 (0.19-0.28) 0.45 (0.39-0.50) 1.0 (0.91-1.1) 1.2 (0.86-1.5)
4 (2014-2015) 533 0 0.50 (0.42-0.59) 0.26 (0.22-0.31) 0.46 (0.36-0.56) 0.96 (0.67-1.2) 1.2 (1.0-1.5)
12-19 years
2 (2009-2011) 505 0 0.32 (0.28-0.35) 0.15 (0.13-0.16) 0.32 (0.28-0.37) 0.62 (0.52-0.72) 0.75 (0.54-0.97)
3 (2012-2013) 548 0 0.29 (0.25-0.33) 0.14 (0.12-0.16) 0.27 (0.23-0.31) 0.61 (0.45-0.76) 0.76 (0.63-0.89)
4 (2014-2015) 481 0 0.29 (0.25-0.34) 0.15 (0.14-0.16) 0.29 (0.22-0.35) 0.57 (0.49-0.64) 0.63 (0.49-0.76)
20-39 years
2 (2009-2011) 352 0 0.46 (0.39-0.55) 0.20 (0.17-0.24) 0.42 (0.33-0.51) 1.1 (0.74-1.4) Footnote F
3 (2012-2013) 371 0 0.40 (0.35-0.46) 0.16 (0.12-0.19) 0.39 (0.30-0.49) 0.87 (0.71-1.0) 1.0 (0.76-1.2)
4 (2014-2015) 369 0 0.35 (0.28-0.44) 0.14Footnote E (0.078-0.20) 0.36 (0.26-0.45) 0.85 (0.68-1.0) 1.0 (0.95-1.1)
40-59 years
2 (2009-2011) 355 0 0.53 (0.46-0.60) 0.22 (0.18-0.26) 0.54 (0.43-0.66) 1.2 (0.94-1.4) 1.6 (1.2-2.0)
3 (2012-2013) 359 0 0.52 (0.46-0.59) 0.22 (0.20-0.24) 0.55 (0.44-0.66) 1.0 (0.87-1.2) 1.2 (0.77-1.7)
4 (2014-2015) 368 0 0.41 (0.34-0.50) 0.17 (0.13-0.21) 0.42 (0.35-0.49) 0.92 (0.67-1.2) 1.2 (0.86-1.6)
60-79 years
2 (2009-2011) 287 0 0.58 (0.50-0.68) 0.22 (0.16-0.27) 0.55 (0.44-0.67) 1.6 (1.3-1.9) 1.9 (1.4-2.5)
3 (2012-2013) 350 0 0.52 (0.43-0.62) 0.20 (0.16-0.24) 0.52 (0.45-0.59) 1.4Footnote E (0.86-1.9) 2.1Footnote E (1.1-3.0)
4 (2014-2015) 340 0 0.49 (0.40-0.59) 0.17 (0.13-0.20) 0.50 (0.37-0.63) 1.5 (0.93-2.0) 2.1Footnote E (1.3-2.9)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

10.4 Lead

Lead (CASRN 7439-92-1) is a naturally occurring element present at a median natural background concentration of 0.0008% in Canada (Rencz et al., 2006). It is a base metal and can exist in various oxidation states and in both inorganic and organic forms (ATSDR, 2007b). Inorganic forms include substances such as elemental lead, lead sulphate, lead carbonate and hydroxyl carbonate, lead oxides, lead chromate, and lead citrate (Rasmussen et al., 2014). Organic lead compounds include tetra-alkyl, trialkyl, and dialkyl lead compounds.

Lead is found in bedrock, soils, sediments, surface water, groundwater, and sea water (Health Canada, 2013e). It enters the environment from a variety of natural and anthropogenic sources. Natural processes include soil weathering, erosion, and volcanic activity (ATSDR, 2007b; IARC, 2006). Lead released from industrial emissions can be a major source of environmental contamination, especially near point sources such as smelters or refineries (ATSDR, 2007b). Historical use of leaded motor fuels has contributed to the ubiquitous distribution of lead throughout the globe (WHO, 2000).

In North America, tetraethyl and tetramethyl lead were added to motor vehicle fuels as an anti-knock agent up until the 1990s. Presently in Canada, the addition of lead to gasoline is prohibited, with the exception of fuels for piston engine aircraft and racing fuels for competition vehicles (Health Canada, 2013e). Lead is currently used in the refining and manufacturing of products such as lead acid automotive batteries, lead shot and fishing weights, sheet lead, lead solder, some brass and bronze products, and some ceramic glazes (ATSDR, 2007b; WHO, 2000). Other uses of lead include dyes in paints and pigments. It is also used in scientific equipment, as a stabilizer in plastics, in military equipment and ammunition, and in radiation detection and medical equipment for radiation shielding (ATSDR, 2007b; WHO, 2000). Lead is also used in the manufacturing of cable sheathing, circuit boards, chemical baths and storage vessel linings, chemical transmission pipes, electrical components, and polyvinyl chloride (Health Canada, 2013e).

Everyone is exposed to trace amounts of lead through food, drinking water, soil, household dust, air, and some consumer products. Over the past 30 years, lead exposure has declined by approximately 75% in Canadians (Statistics Canada, 2013b). The substantial decrease in exposure to lead is attributed mainly to the phase-out of leaded gasoline, reduction of lead content in paint and surface coatings, and the elimination of lead solder in food cans (Health Canada, 2013f). Today, the main route of exposure for the general adult population is from ingestion of food and drinking water (ATSDR, 2007b; Health Canada, 2013e). For infants and children, the primary sources of exposure are food, drinking water, and the ingestion of non-food items containing lead such as house dust, paint, soil, and consumer products (Health Canada, 2013e). Lead can enter the water supply from lead service lines in older homes, brass plumbing fittings that contain lead, or lead solder in the plumbing in homes (Health Canada, 2016f). Other potential sources of exposure include costume jewellery, art supplies, leaded crystal, and glazes on ceramics and pottery; having a hobby, or living with someone who has, that uses lead or lead solder, such as making stained glass, ceramic glazing, lead shot or lead fishing weights, and furniture refinishing; living near airports with piston aircraft activity; and behaviours such as smoking (Health Canada, 2013f). The Canadian House Dust Study reported that lead is enriched in house dust compared with the natural geochemical background, as a result of the use of lead in consumer products, paints and building materials, and infiltration from outdoor sources (Rasmussen et al., 2011; Rasmussen et al., 2013).

Approximately 3% to 10% of ingested lead is absorbed into blood in adults; the amount absorbed can increase to up to 40% to 50% in children (Health Canada, 2013e). Nutritional calcium and iron deficiencies in children appear to increase lead absorption and decrease lead excretion (Health Canada, 2013e). Once absorbed by the human body, lead circulates in the bloodstream where it accumulates in tissues, particularly bone, and is excreted from the body. Some lead may also be absorbed into soft tissues such as the liver, kidneys, pancreas, and lungs. Bones account for approximately 70% of the total body burden of lead in children and more than 90% of the total body burden in adults (EPA, 2006a). Lead stored in bone can be remobilized and released back into circulating blood. Pregnancy, lactation, menopause, andropause, post-menopause, extended bed rest, hyperparathyroidism, and osteoporosis are all conditions that can increase remobilization of lead from bone, increasing blood lead levels (Health Canada, 2013e).

During pregnancy, lead stored in maternal bone becomes a source of exposure to both fetus and mother (Rothenberg et al., 2000). Lead can also be present in breast milk and is transferred from lactating mothers to infants (ATSDR, 2007b; EPA, 2006a). The half-life for lead in blood is approximately 30 days whereas the half-life for lead accumulated in the body, such as in bone, is around 10 to 30 years (ATSDR, 2007b; Health Canada, 2009a; Health Canada, 2013e). Excretion of absorbed lead, independent of the route of exposure, occurs primarily in urine and feces (ATSDR, 2007b). Blood lead is the preferred indicator of human exposure to lead, although other matrices such as urine, bone, and teeth also have been used (ATSDR, 2007b; CDC, 2009).

Lead is considered a cumulative general poison, with developing fetuses, infants, toddlers, and children being most susceptible to adverse health effects (WHO, 2011d). Following acute exposure, a variety of metabolic processes may be affected. Very high exposure may result in vomiting, diarrhea, convulsions, coma, and death. Cases of lead poisoning are rare in Canada (Health Canada, 2009d). Symptoms of chronic exposure to relatively low levels of lead are often not apparent (ATSDR, 2007b). Chronic low-level exposure may affect both the central and peripheral nervous systems (Health Canada, 2013e). Chronic low-level exposure to lead has also been associated with developmental neurotoxicity, increases in blood pressure, decreases in renal functioning, and reproductive problems as well as other health endpoints (ATSDR, 2007b; Bushnik et al., 2014; Health Canada, 2013e). Cognitive and neurobehavioural effects have been recognized as major concerns for children exposed to lead. In infants and children, neurodevelopmental effects are most strongly associated with lead exposure, specifically the reduction of intelligence quotient (Lanphear et al., 2005) and an increased risk of attention-related behaviours (Health Canada, 2013e). Based on available data, no threshold has yet been identified for the effects of lead exposure on cognitive function and neurobehavioural development (CDC, 2012; EPA, 2006a; Health Canada, 2013e). Developmental neurotoxicity has been associated with the lowest levels of lead exposure measured to date (Health Canada, 2013e). The International Agency for Research on Cancer classifies inorganic lead compounds as Group 2A, probably carcinogenic to humans (IARC, 2006).

Lead is listed on Schedule 1, List of Toxic Substances, under the Canadian Environmental Protection Act, 1999 (CEPA 1999). The Act allows the federal government to control the importation, manufacture, distribution, and use of lead and lead compounds in Canada (Canada, 1999; Health Canada, 2009d). CEPA 1999 prohibits the addition of lead in gasoline and controls its release from secondary lead smelters, steel manufacturing, and mining effluents (Environment Canada, 2010b). The use of lead in toys, children's jewellery and other products intended for children, glazed ceramics and glass foodware, and other consumer products representing a potential risk of lead exposure is limited under the Canada Consumer Product Safety Act and its associated regulations (Canada, 2010a; Canada, 2010c; Health Canada, 2013e). These regulations include the Children's Jewellery Regulations which propose a new guideline limit for lead in children's jewellery (Canada, 2016a). In addition, the Consumer Products Containing Lead Regulations have been recently proposed with a total lead limit for an expanded scope of products (Canada, 2016b). Lead and its compounds are also included as prohibited ingredients on the List of Prohibited and Restricted Cosmetic Ingredients (more commonly referred to as the Cosmetic Ingredient Hotlist or simply the Hotlist) (Health Canada, 2015b). The Hotlist is an administrative tool that Health Canada uses to communicate to manufacturers and others that certain substances, when present in a cosmetic, may contravene the general prohibition found in section 16 of the Food and Drugs Act or a provision of the Cosmetic Regulations.

On the basis of health considerations, Health Canada, in collaboration with the Federal-Provincial-Territorial Committee on Drinking Water, developed a guideline for Canadian drinking water quality that establishes the maximum acceptable concentration for lead (Health Canada, 1992a). This guideline is currently under review by Health Canada in collaboration with the Federal-Provincial-Territorial Committee on Drinking Water (Health Canada, 2017). Health Canada has also published guidance on controlling corrosion in drinking water distribution systems to help control the leaching of metals, including lead, from the corrosion of distribution system materials and components (Health Canada, 2009e). The concentration of lead in some foods is managed by Health Canada under the Food and Drug Regulations; the existing maximum levels are in the process of being updated, with focus first being placed on a variety of beverages, including bottled water and fruit juices (Canada, 2012c; Health Canada, 2011a; Health Canada, 2014c). These regulatory updates are some of several Health Canada activities that are under way to ensure that dietary exposure to lead is as low as reasonably achievable (Health Canada, 2011a). Lead is also included in the list of various chemicals analyzed as part of Health Canada's ongoing Total Diet Study surveys (Health Canada, 2013d). The food items analyzed represent those that are most typical of the Canadian diet, and the surveys are used to provide dietary exposure estimates for chemicals that Canadians in different age-sex groups are exposed to through the food supply. From 1981 to 2000, the average dietary exposure to lead in Canadians decreased by approximately eight-fold (Health Canada, 2011a).

In 1994, the Federal-Provincial-Territorial Committee on Environmental and Occupational Health recommended a blood lead intervention level of 10 µg/dL as guidance for low-level exposure to lead (CEOH, 1994). Recent scientific assessments indicate that chronic health effects are occurring in children at blood lead levels below 10 µg/dL and that there is sufficient evidence that blood lead levels below 5 µg/dL are associated with adverse health effects (Health Canada, 2013e). The current guidance for lead in blood (CEOH, 1994) is under review by the federal, provincial, and territorial Council of Chief Medical Officers of Health.

A number of biomonitoring studies measuring blood lead levels have been conducted in various locations in Canada over the years. The reported geometric mean blood lead levels ranged from 0.7 µg/dL to 5.6 µg/dL for various age groups within the Canadian population (Health Canada, 2013e). The highest concentrations were reported for communities with point sources of environmental lead such as smelting (Trail Health and Environment Committee, 2011). In Northern Canada, the contaminant component of the Inuit Health Survey (2007-2008) has measured the body burden of lead for 2,172 Inuit participants from 36 communities in Nunavut, Nunatsiavut, and the Inuvialuit Settlement Region (Laird et al., 2013). The geometric mean blood lead level for all participants (18 years and older) was 3.52 µg/dL. In 2008, a study conducted in Hamilton on 643 children aged 0-6 years reported a geometric mean blood lead level of 2.21 µg/dL (Richardson et al., 2011). The First Nations Biomonitoring Initiative (FNBI) is a nationally representative biomonitoring study of adult First Nations peoples living on reserves south of the 60° parallel (AFN, 2013). It comprises 13 randomly selected First Nation communities in Canada with 503 First Nations participants aged 20 years and older. In 2011, the geometric mean and 95th percentile for lead in blood were 1.17 µg/dL and 3.27 µg/dL, respectively.

Lead was analyzed in the whole blood of all Canadian Health Measures Survey participants aged 6-79 years in cycle 1 (2007-2009), and 3-79 years in cycle 2 (2009-2011), cycle 3 (2012-2013), and cycle 4 (2014-2015). Data from these cycles are presented in blood as µg/dL.

Table 10.4.1 - Lead - Geometric means and selected percentiles of whole blood concentrations (μg/dL) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 1 (2007-2009), cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 6070 0 1.2 (1.1-1.2) 0.54 (0.50-0.59) 1.1 (1.1-1.2) 2.5 (2.3-2.7) 3.2 (2.9-3.4)
3 (2012-2013) 5538 0.09 1.1 (1.0-1.1) 0.49 (0.46-0.52) 1.0 (0.95-1.1) 2.4 (2.3-2.5) 3.2 (2.9-3.4)
4 (2014-2015) 5498 0.13 0.95 (0.90-1.0) 0.43 (0.40-0.46) 0.92 (0.88-0.95) 2.1 (1.8-2.3) 2.7 (2.4-3.0)
Males, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 2940 0 1.3 (1.3-1.4) 0.62 (0.56-0.67) 1.2 (1.2-1.3) 2.8 (2.5-3.1) 3.4 (3.1-3.7)
3 (2012-2013) 2769 0.07 1.2 (1.2-1.3) 0.56 (0.55-0.58) 1.1 (1.0-1.2) 2.6 (2.4-2.9) 3.6 (3.1-4.0)
4 (2014-2015) 2754 0.07 1.0 (0.98-1.1) 0.47 (0.45-0.49) 1.0 (0.97-1.0) 2.2 (1.9-2.4) 2.9 (2.3-3.5)
Females, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 3130 0 1.1 (1.0-1.1) 0.50 (0.46-0.54) 1.0 (0.96-1.1) 2.3 (2.1-2.5) 2.8 (2.6-3.0)
3 (2012-2013) 2769 0.11 0.96 (0.90-1.0) 0.42 (0.37-0.47) 0.93 (0.87-1.0) 2.2 (2.1-2.3) 2.6 (2.2-3.1)
4 (2014-2015) 2744 0.18 0.87 (0.81-0.94) 0.40 (0.36-0.43) 0.83 (0.78-0.89) 2.0 (1.6-2.3) 2.6 (2.3-2.8)
3-5 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 495 0 0.93 (0.87-1.0) 0.51 (0.44-0.58) 0.93 (0.86-1.0) 1.6 (1.5-1.8) 2.1 (1.8-2.4)
3 (2012-2013) 471 0 0.77 (0.73-0.82) 0.40 (0.33-0.47) 0.72 (0.68-0.77) 1.4 (1.0-1.8) 2.2 (1.4-2.9)
4 (2014-2015) 479 0 0.67 (0.61-0.73) 0.37 (0.32-0.42) 0.64 (0.60-0.69) 1.2 (0.90-1.5) 1.7 (1.4-2.0)
6-11 years
1 (2007-2009) 910 0 0.90 (0.81-0.99) 0.53 (0.49-0.56) 0.87 (0.77-0.97) 1.6 (1.4-1.7) 1.9 (1.6-2.2)
2 (2009-2011) 961 0 0.79 (0.74-0.84) 0.44 (0.38-0.50) 0.74 (0.68-0.81) 1.4 (1.2-1.6) 1.7 (1.5-1.9)
3 (2012-2013) 944 0 0.71 (0.67-0.76) 0.39 (0.36-0.42) 0.67 (0.64-0.71) 1.3 (1.1-1.5) 1.6 (1.3-1.9)
4 (2014-2015) 925 0.22 0.59 (0.55-0.62) 0.33 (0.31-0.35) 0.56 (0.52-0.59) 1.0 (0.89-1.1) 1.3 (1.0-1.5)
12-19 years
1 (2007-2009) 945 0 0.80 (0.74-0.85) 0.47 (0.44-0.50) 0.76 (0.70-0.82) 1.3 (1.1-1.5) 1.6 (1.4-1.8)
2 (2009-2011) 997 0 0.71 (0.68-0.75) 0.39 (0.35-0.43) 0.68 (0.63-0.72) 1.2 (1.1-1.2) 1.6 (1.3-1.8)
3 (2012-2013) 977 0.10 0.64 (0.60-0.69) 0.34 (0.32-0.36) 0.60 (0.56-0.64) 1.2 (1.1-1.4) 1.5 (1.3-1.6)
4 (2014-2015) 974 0.31 0.54 (0.50-0.57) 0.30 (0.28-0.33) 0.51 (0.47-0.54) 0.98 (0.91-1.0) 1.1 (0.94-1.2)
20-39 years
1 (2007-2009) 1165 0.09 1.1 (1.0-1.2) 0.57 (0.52-0.61) 1.0 (0.95-1.1) 2.3 (2.0-2.6) 3.1 (2.7-3.4)
2 (2009-2011) 1313 0 0.98 (0.88-1.1) 0.50 (0.43-0.57) 0.94 (0.87-1.0) 1.8 (1.5-2.1) 2.2 (1.6-2.9)
3 (2012-2013) 1032 0.19 0.90 (0.79-1.0) 0.44 (0.36-0.53) 0.88 (0.79-0.97) 1.7 (1.5-2.0) 2.1 (1.8-2.4)
4 (2014-2015) 1074 0.19 0.80 (0.74-0.88) 0.43 (0.39-0.47) 0.78 (0.67-0.88) 1.5 (1.2-1.7) 2.0 (1.6-2.5)
40-59 years
1 (2007-2009) 1220 0 1.6 (1.5-1.8) 0.82 (0.69-0.94) 1.5 (1.4-1.6) 3.1 (2.6-3.6) 3.8 (3.1-4.5)
2 (2009-2011) 1222 0 1.4 (1.3-1.5) 0.70 (0.61-0.79) 1.4 (1.3-1.4) 2.7 (2.4-3.0) 3.2 (2.9-3.5)
3 (2012-2013) 1071 0.09 1.3 (1.3-1.4) 0.61 (0.55-0.68) 1.3 (1.2-1.4) 2.6 (2.2-2.9) 3.5 (2.9-4.2)
4 (2014-2015) 1051 0 1.2 (1.0-1.3) 0.58 (0.53-0.63) 1.1 (1.0-1.1) 2.4 (1.9-2.9) 3.2 (2.3-4.0)
60-79 years
1 (2007-2009) 1079 0 2.1 (1.9-2.3) 1.0 (0.92-1.1) 2.0 (1.8-2.2) 4.1 (3.5-4.8) 5.2 (4.2-6.2)
2 (2009-2011) 1082 0 1.9 (1.8-1.9) 1.0 (0.94-1.1) 1.7 (1.7-1.8) 3.5 (3.2-3.8) 4.2 (3.8-4.6)
3 (2012-2013) 1043 0.10 1.6 (1.6-1.7) 0.81 (0.78-0.85) 1.6 (1.4-1.7) 3.3 (3.0-3.5) 4.0 (3.6-4.4)
4 (2014-2015) 995 0 1.5 (1.4-1.6) 0.74 (0.66-0.81) 1.4 (1.3-1.5) 2.9 (2.5-3.3) 3.8 (3.0-4.6)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

b Data not available as participants under the age of 6 years were not included in cycle 1 (2007-2009).

10.5 Mercury

Mercury (CASRN 7439-97-6) is a naturally occurring soft, silvery white metal present in the Earth's crust at an average concentration of approximately 0.000005% (Emsley, 2001). It is the only metal that is a liquid at room temperature. Mercury exists in elemental, inorganic, and organic forms (CCME, 1999b). Elemental and certain organic forms of mercury have sufficiently high vapour pressures to be present as vapour in air (ATSDR, 1999a; ATSDR, 2013). The most common organic mercury compounds in nature are methylmercury (monomethylmercury) and dimethylmercury. Mercury can be converted among its elemental, inorganic, and organic forms by a variety of processes, including biological transformation (Environment Canada, 2010c).

Mercury is found throughout the environment, including remote Arctic regions because of its persistence, mobility, and tendency to accumulate in colder climates. Natural sources include volcanic activity and natural erosion of mercury-containing deposits (Environment Canada and Health Canada, 2010). Metabolism of inorganic mercury by micro-organisms in the environment creates organic mercury (methylmercury) that often bioaccumulates in terrestrial and aquatic food chains (ATSDR, 1999a; ATSDR, 2013). Anthropogenic sources of inorganic mercury include metal mining and smelting; combustion of fossil fuels, particularly coal; incineration of municipal wastes; cement production; and sewage sludge and waste water (UNEP, 2002). Inorganic mercury may also be released to the environment following disposal of products containing mercury.

Mercury has unique properties that have made it useful in certain products such as wiring devices, switches, and scientific measuring devices, including vacuum gauges and thermometers (ATSDR, 1999a; ATSDR, 2013). Today the manufacture and import of most mercury-containing products are prohibited in Canada. Exemptions include certain essential products such as certain medical and research applications, dental amalgams, and fluorescent and other types of lamps (Canada, 2014). Use of mercury-containing light bulbs is increasing because of widespread replacement of incandescent bulbs with compact fluorescent bulbs. Mercury is also used as an industrial catalyst and in laboratory reagents, disinfectants, embalming solutions, and some pharmaceuticals. A significant use of inorganic mercury is in dental amalgam, which is composed of approximately 50% mercury (IMERC, 2010; SCENIHR, 2015). Based on data collected as part of the Canadian Health Measures Survey (CHMS) cycle 1 (2007-2009), it was estimated that approximately 63.95% of the Canadian population age 6 and over had one or more amalgam-restored tooth surfaces (Richardson, 2014).

Mercury exposure in the general population is primarily through the consumption of fish and seafood in which methylmercury is the predominant form (Health Canada, 2007a). To a lesser extent, the general population is exposed to inorganic mercury from such sources as dental amalgams (Health Canada, 1996, Health Canada, 2004; SCENIHR 2015). The general population may also be exposed to elemental mercury via inhalation of vapours in ambient air, ingestion, or through dental and medical treatments (ATSDR, 1999a).

Approximately 95% of organic mercury is absorbed from the gastrointestinal tract following oral ingestion (ATSDR, 1999a; ATSDR, 2013). Following absorption, organic mercury is distributed to all tissues, including hair, with highest accumulation in the kidneys. It readily passes the blood-brain barrier and enters the brain, and in pregnant women can easily cross the placental barrier into the fetus (Health Canada, 2004). Absorbed organic mercury is demethylated in the body to inorganic mercury that accumulates primarily in the liver and kidneys. The biological half-life of methylmercury is approximately 50 days. The majority of mercury in the body is excreted via feces, with a small amount excreted as inorganic mercury in urine (ATSDR, 1999a; ATSDR, 2013).

Generally less than 10% of inorganic mercury is absorbed through the intestinal tract (Health Canada, 2004). Absorbed inorganic mercury accumulates readily in the kidneys (IPCS, 2003). It also accumulates in placental tissues but does not cross placental or blood-brain barriers as easily as elemental or methylmercury (Health Canada, 2004). Excretion of elemental and inorganic mercury compounds occurs mainly in urine and feces with an absorbed dose half-life of approximately 1 to 2 months (IPCS, 2003).

Elemental mercury is absorbed across the lungs and gastrointestinal tract with absorption rates of about 80% and 0.01%, respectively (Health Canada, 2004). Once absorbed, elemental mercury enters the bloodstream and is rapidly transported to other parts of the body, including the brain and kidneys. As with organic mercury, it readily crosses the blood-brain and placental barriers (Health Canada, 2004). Once in the body, elemental mercury is oxidized in the tissues to inorganic forms and can remain for weeks or months with an estimated half-life of approximately 60 days (Sandborgh-Englund et al., 1998).

Long-term exposure to elemental and inorganic mercury is commonly evaluated using mercury concentrations in urine (IPCS, 2003). Hair also may be used as a biomarker of chronic exposure, although inorganic forms of mercury are not excreted to any significant amount in scalp hair, making it an inappropriate biomarker of inorganic mercury exposure (ATSDR, 1999a; ATSDR, 2013; IPCS, 2003). Total blood mercury concentrations primarily reflect recent dietary exposure to organic forms of mercury, particularly methylmercury (ATSDR, 1999a; ATSDR, 2013; IPCS, 2003). The concentration of total mercury in blood is accepted as a reasonable measure of methylmercury exposure; however, methylmercury itself may also be measured directly in blood. Based on a review of existing data from other countries, the World Health Organization has estimated that the average total blood mercury concentration for the general population is approximately 8 µg/L (WHO, 1990). In individuals who consume fish daily, methylmercury concentrations in blood can be as high as 200 µg/L (WHO, 1990).

Mercury is known to be toxic to humans, with the effects depending on the mercury form, the route of exposure, the timing of exposure, and the absorbed concentration. Chronic oral exposure to low levels of methylmercury may not result in any observable symptoms (Health Canada, 2007a). The primary effects associated with oral exposure to organic mercury compounds are neurological effects and developmental neurotoxicity (ATSDR, 2013; EFSA CONTAM Panel, 2012; FAO/WHO, 2011d; Health Canada, 2007a). Symptoms of organic mercury toxicity include a tingling sensation in the extremities; impaired peripheral vision, hearing, taste, and smell; slurred speech; muscle weakness and an unsteady gait; irritability; memory loss; depression; and sleeping difficulties. Exposure of a fetus or young child to organic mercury can result in effects on the development of the nervous system, affecting fine-motor function, attention, verbal learning, and memory (ATSDR, 2013; Health Canada, 2007a). Exposure to elemental mercury may be hazardous, depending upon the levels of exposure, because the vapour that can be released from this form is readily absorbed into the body through inhalation. Inhalation of mercury vapour may cause respiratory, cardiovascular, kidney, and neurological effects. In 1996, Health Canada concluded that mercury exposure from dental amalgams does not pose a health impact for the general population (Health Canada, 1996). Subsequent studies since this report have concurred that exposure to inorganic mercury from dental amalgams has not been associated with neurologic effects in children or adults (Bates et al., 2004; Bellinger et al., 2007; DeRouen et al., 2006; Factor-Litvak et al., 2003; SCENIHR, 2015).

The International Agency for Research on Cancer (IARC) determined that methylmercury compounds are possibly carcinogenic to humans (Group 2B), based on animal data showing a link to certain cancers, particularly renal cancer (IARC, 1993). Elemental mercury and inorganic mercury compounds were classified by IARC as Group 3, not classifiable as to their carcinogenicity to humans (IARC, 1993).

The United Nations Environment Programme (UNEP) Global Risk Assessment for Mercury concluded that there was sufficient evidence of adverse impacts from mercury to warrant further international action to reduce the risks to human health and the environment (UNEP, 2002). International negotiations under UNEP resulted in the signing of the Minamata Convention on Mercury, a global legally binding agreement to prevent mercury emissions and releases (UNEP, 2013). The Minamata Convention is intended to reduce global atmospheric emissions, supply, trade, and demand for mercury, and to find environmentally sound solutions for storage of mercury and mercury-containing wastes.

In Canada, mercury and its compounds are listed as toxic substances on Schedule 1 of the Canadian Environmental Protection Act, 1999 (CEPA 1999) (Canada, 1999; Canada, 2012d). Existing and planned actions to manage the risks from mercury are summarized in the Government of Canada's Risk Management Strategy for Mercury (Environment Canada and Health Canada, 2010). These risk management actions include several Canada-wide standards that have been established to reduce the releases of mercury to the environment (CCME, 2000a; CCME, 2005; CCME, 2006; CCME, 2007). The Products Containing Mercury Regulations came into force in 2015, and prohibit the manufacture and import of products containing mercury or any of its compounds as well as provide content limits for exempted products (Canada, 2014). The Surface Coating Materials Regulations, in effect under the Canada Consumer Product Safety Act, restrict the level of mercury in all surface coating materials advertised, sold, or imported into Canada (Canada, 2005). In addition, the Toys Regulations prohibit any compound of mercury in the surface coating material that is applied to a product that is used by a child in learning or play situations (Canada, 2011b). Mercury and its compounds are also included as prohibited ingredients on the List of Prohibited and Restricted Cosmetic Ingredients (more commonly referred to as the Cosmetic Ingredient Hotlist or simply the Hotlist). The Hotlist is an administrative tool that Health Canada uses to communicate to manufacturers and others that certain substances, when present in a cosmetic, may contravene the general prohibition found in section 16 of the Food and Drugs Act or a provision of the Cosmetic Regulations (Canada, 1985a; Health Canada, 2015b). The Food and Drug Regulations prohibit sale in Canada of drugs for human use containing mercury or any of its salts or derivatives except in some specific instances, including those where it is present as a preservative (Canada, 2012c).

Health Canada has established a methylmercury blood guidance value of 20 µg/L for the general adult population, for which levels below this value are considered in the normal acceptable range (Health Canada, 2004). For children (under 18 years of age), pregnant women, and women of childbearing age (under 50 years of age), a provisional methylmercury blood guidance value of 8 µg/L has been proposed for the protection of the developing nervous system (Legrand et al., 2010). On the basis of health considerations, Health Canada, in collaboration with the Federal-Provincial-Territorial Committee on Drinking Water, has developed a guideline for Canadian drinking water quality that establishes the maximum acceptable concentration for mercury in drinking water (Health Canada, 1986b; Health Canada, 2014d). Health Canada has also established maximum levels for mercury in retail fish (Health Canada, 2012d), and provided consumption advice for consumers of certain types of fish (Health Canada, 2008c). Eating Well with Canada's Food Guide recommends eating at least two food guide servings each week of fish that are low in mercury and high in omega-3 fatty acids (Health Canada, 2011b). Mercury is also included in the list of various chemicals analyzed as part of Health Canada's ongoing Total Diet Study surveys (Health Canada, 2013d). The food items analyzed represent those that are most typical of the Canadian diet, and the surveys are used to provide dietary exposure estimates for chemicals that Canadians in different age-sex groups are exposed to through the food supply.

During cycle 1 (2007-2009) of the CHMS, the geometric mean total mercury level in blood of the Canadian population aged 6-79 years was 0.69 µg/L (Lye et al., 2013). The majority (97.8%) of Canadian women aged 16-49 years, including pregnant women, had blood mercury values below the provisional Health Canada blood guidance value of 8 µg/L (Lye et al., 2013). The geometric mean urinary inorganic mercury concentration in dental amalgam-free participants from cycle 1 of the CHMS was 0.10 µg/L compared with the geometric mean concentration for all participants of 0.22 µg/L (Nicolae et al., 2013). In general, mean urinary inorganic mercury concentrations tended to increase with the number of amalgam surfaces and appeared to be influenced by age and sex (Nicolae et al., 2013). The population coverage of the CHMS excludes persons living on reserves and other Aboriginal settlements in the provinces of Canada. However, this subpopulation has been surveyed as part of the First Nations Biomonitoring Initiative (FNBI), a nationally representative biomonitoring study of adult First Nations peoples living on reserves south of the 60° parallel (AFN, 2013). It comprises 13 randomly selected First Nation communities in Canada with 503 First Nations participants aged 20 years and older. In 2011, the geometric mean and 95th percentile for total mercury in blood were 0.95 µg/L and 9.28 µg/L, respectively. For inorganic mercury in urine, the geometric mean and 95th percentile were 0.26 µg/L and 1.98 µg/L, respectively.

Total mercury was analyzed in the whole blood of all CHMS participants aged 6-79 years in cycle 1 (2007-2009), and 3-79 years in cycle 2 (2009-2011), cycle 3 (2012-2013), and cycle 4 (2014-2015). Methylmercury was analyzed in the whole blood of CHMS participants aged 20-79 years in cycle 3 (2012-2013) and cycle 4 (2014-2015). Inorganic mercury was analyzed in the urine of all CHMS participants aged 6-79 years in cycle 1 (2007-2009) and 3 to 79 years in cycle 3 (2012-2013) and cycle 4 (2014-2015). Data from these cycles are presented in blood as µg/L and in urine as both µg/L and µg/g creatinine. Finding a measurable amount of mercury in blood or urine is an indicator of exposure to mercury and does not necessarily mean that an adverse health effect will occur.

Table 10.5.1 - Mercury (total) - Geometric means and selected percentiles of whole blood concentrations (μg/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 1 (2007-2009), cycle 2 (2009-2011), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 6070 15.55 0.69 (0.56-0.87) <LOD 0.74 (0.55-0.93) 3.4 (2.4-4.5) 5.5Footnote E (3.3-7.6)
3 (2012-2013) 5538 37.02 0.79 (0.64-0.97) <LOD 0.79 (0.62-0.96) 3.2Footnote E (1.5-4.9) 5.2Footnote E (3.0-7.5)
4 (2014-2015) 5498 44.82 - <LOD 0.59 (0.47-0.72) 2.5 (1.9-3.1) 3.5 (2.9-4.2)
Males, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 2940 16.16 0.72 (0.56-0.91) <LOD 0.76 (0.53-0.99) 3.9 (2.7-5.1) 6.1Footnote E (2.7-9.5)
3 (2012-2013) 2769 37.63 0.76 (0.60-0.97) <LOD 0.74 (0.54-0.94) 3.2Footnote E (1.3-5.0) 5.6Footnote E (3.4-7.8)
4 (2014-2015) 2754 44.99 - <LOD 0.58 (0.45-0.71) 2.8 (2.0-3.6) 3.7 (2.6-4.8)
Females, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 3130 14.98 0.67 (0.54-0.83) <LOD 0.71 (0.53-0.88) 3.0 (2.0-4.0) 5.1Footnote E (3.0-7.1)
3 (2012-2013) 2769 36.40 0.81 (0.67-0.99) <LOD 0.82 (0.67-0.97) 3.2Footnote E (1.4-4.9) 5.1Footnote E (2.4-7.8)
4 (2014-2015) 2744 44.64 - <LOD 0.60 (0.47-0.74) 2.2 (1.6-2.8) 3.3 (2.7-4.0)
3-5 years
1 (2007-2009)Footnote b - - - - - - -
2 (2009-2011) 495 29.90 0.27 (0.20-0.36) <LOD 0.19Footnote E (<LOD-0.29) 1.4Footnote E (0.44-2.3) 3.0Footnote E (1.7-4.3)
3 (2012-2013) 471 59.45 - <LOD <LOD 1.3 (1.0-1.7) 1.7Footnote E (0.88-2.5)
4 (2014-2015) 479 71.19 - <LOD <LOD 0.85Footnote E (<LOD-1.3) 1.3Footnote E (0.54-2.1)
6-11 years
1 (2007-2009) 910 24.84 0.26 (0.22-0.32) <LOD 0.24 (0.18-0.29) 1.3 (1.0-1.6) 2.1Footnote E (1.3-2.9)
2 (2009-2011) 961 29.03 0.28 (0.22-0.34) <LOD 0.21Footnote E (0.11-0.30) 1.2 (0.84-1.5) 2.0 (1.3-2.6)
3 (2012-2013) 944 54.77 - <LOD <LOD 1.2 (0.78-1.7) 1.9Footnote E (0.91-2.9)
4 (2014-2015) 925 59.57 - <LOD <LOD 1.1 (0.84-1.3) 1.5 (0.96-2.0)
12-19 years
1 (2007-2009) 945 20.85 0.30 (0.23-0.40) <LOD 0.28 (0.20-0.37) 1.3Footnote E (0.47-2.2) 2.2Footnote E (0.88-3.5)
2 (2009-2011) 997 26.58 0.27 (0.21-0.35) <LOD 0.19Footnote E (<LOD-0.30) 1.3 (0.84-1.7) 2.4Footnote E (1.3-3.5)
3 (2012-2013) 977 52.61 - <LOD <LOD 1.6Footnote E (0.62-2.6) 2.8Footnote E (1.3-4.4)
4 (2014-2015) 975 61.33 - <LOD <LOD 1.3 (0.92-1.7) 2.2Footnote E (1.2-3.2)
20-39 years
1 (2007-2009) 1165 8.76 0.65 (0.52-0.81) <LOD 0.76 (0.61-0.91) 3.0Footnote E (1.9-4.1) 4.9Footnote E (2.4-7.4)
2 (2009-2011) 1313 10.05 0.64 (0.47-0.85) <LOD 0.65 (0.43-0.86) 2.9 (2.0-3.9) 5.2Footnote E (2.6-7.8)
3 (2012-2013) 1032 30.91 0.82 (0.65-1.0) <LOD 0.77 (0.57-0.96) 4.1Footnote E (1.5-6.6) 6.0Footnote E (3.6-8.3)
4 (2014-2015) 1073 40.54 - <LOD 0.48 (<LOD-0.65) 2.0 (1.6-2.4) 2.9 (2.0-3.8)
40-59 years
1 (2007-2009) 1220 3.52 1.0 (0.80-1.3) 0.21Footnote E (0.12-0.30) 1.1 (0.83-1.3) 3.6 (2.3-4.9) 6.4Footnote E (3.0-9.8)
2 (2009-2011) 1222 5.16 1.0 (0.79-1.3) 0.15 (0.11-0.20) 1.0 (0.84-1.2) 4.1Footnote E (2.4-5.8) 7.3Footnote E (2.5-12)
3 (2012-2013) 1071 20.54 0.96 (0.74-1.2) <LOD 0.99 (0.78-1.2) 3.4Footnote E (1.5-5.4) 5.2Footnote E (2.8-7.6)
4 (2014-2015) 1051 27.69 0.77 (0.65-0.92) <LOD 0.80 (0.63-0.98) 3.1 (2.2-4.1) 3.7 (2.9-4.6)
60-79 years
1 (2007-2009) 1079 4.73 0.87 (0.64-1.2) Footnote F 0.96 (0.75-1.2) 3.4 (2.4-4.4) 4.8Footnote E (2.7-6.9)
2 (2009-2011) 1082 5.27 1.1 (0.86-1.5) 0.17Footnote E (<LOD-0.28) 1.2 (0.89-1.5) 4.3 (3.1-5.5) 6.5Footnote E (3.9-9.1)
3 (2012-2013) 1043 19.18 1.0 (0.82-1.3) <LOD 0.99 (0.71-1.3) 3.8Footnote E (2.2-5.3) 6.7Footnote E (1.9-11)
4 (2014-2015) 995 24.92 0.88 (0.73-1.1) <LOD 0.92 (0.76-1.1) 3.3 (2.6-4.0) 4.6 (3.1-6.1)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

b Data not available as participants under the age of 6 years were not included in cycle 1 (2007-2009).

E Use data with caution.

Table 10.5.2 - Mercury (inorganic) - Geometric means and selected percentiles of urine concentrations (μg/L) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 1 (2007-2009), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 5696 50.42 - <LOD <LOD 1.3 (1.1-1.5) 2.0 (1.7-2.3)
4 (2014-2015) 5595 56.35 - <LOD <LOD 1.3 (0.94-1.6) 2.2 (1.7-2.7)
Males, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 2842 49.37 - <LOD 0.20Footnote E (<LOD-0.27) 1.2 (0.92-1.5) 1.9 (1.3-2.4)
4 (2014-2015) 2809 55.68 - <LOD <LOD 1.3 (0.87-1.7) 2.2 (1.5-2.9)
Females, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 2854 51.47 - <LOD <LOD 1.4 (0.97-1.8) 2.1 (1.5-2.8)
4 (2014-2015) 2786 57.04 - <LOD <LOD 1.3 (0.82-1.7) 2.2Footnote E (1.3-3.2)
3-5 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 520 74.81 - <LOD <LOD 0.28Footnote E (<LOD-0.48) 0.59Footnote E (0.35-0.84)
4 (2014-2015) 512 83.98 - <LOD <LOD 0.25Footnote E (<LOD-0.36) 0.41Footnote E (0.20-0.61)
6-11 years
1 (2007-2009) 1028 66.05 - <LOD <LOD 0.99Footnote E (0.56-1.4) 1.8Footnote E (0.99-2.7)
3 (2012-2013) 1010 61.29 - <LOD <LOD 0.93Footnote E (0.50-1.4) Footnote F
4 (2014-2015) 1008 69.94 - <LOD <LOD 0.58Footnote E (0.35-0.80) 1.3 (0.93-1.8)
12-19 years
1 (2007-2009) 975 57.54 - <LOD <LOD 1.2 (0.76-1.6) 2.2 (1.5-3.0)
3 (2012-2013) 997 59.58 - <LOD <LOD 0.55Footnote E (0.33-0.78) 1.1Footnote E (0.53-1.6)
4 (2014-2015) 988 65.49 - <LOD <LOD 0.53 (0.38-0.68) 0.96 (0.65-1.3)
20-39 years
1 (2007-2009) 1166 46.23 - <LOD 0.22 (0.16-0.28) 1.4 (1.0-1.7) 2.3 (1.8-2.7)
3 (2012-2013) 1048 45.13 - <LOD 0.20Footnote E (<LOD-0.28) 1.1 (0.87-1.3) 1.9Footnote E (0.89-3.0)
4 (2014-2015) 1057 50.99 - <LOD <LOD 1.1Footnote E (0.50-1.6) 2.1Footnote E (1.1-3.1)
40-59 years
1 (2007-2009) 1207 36.04 0.31 (0.25-0.37) <LOD 0.37 (0.28-0.47) 2.5 (1.8-3.2) 3.5 (2.3-4.7)
3 (2012-2013) 1080 36.20 0.31 (0.26-0.39) <LOD 0.30 (0.20-0.40) 1.7 (1.2-2.2) 2.2 (1.7-2.6)
4 (2014-2015) 1037 40.31 - <LOD 0.26 (0.21-0.32) 1.9 (1.3-2.5) 3.5Footnote E (2.0-5.1)
60-79 years
1 (2007-2009) 1068 45.69 - <LOD 0.25Footnote E (0.15-0.35) 2.0 (1.4-2.5) 3.0 (2.5-3.5)
3 (2012-2013) 1041 39.00 0.26 (0.23-0.30) <LOD 0.24 (0.18-0.30) 1.4 (0.98-1.8) 2.3 (1.6-2.9)
4 (2014-2015) 993 41.69 - <LOD 0.26 (0.20-0.32) 1.5 (1.1-1.9) 2.4 (2.0-2.7)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

b Data not available as participants under the age of 6 years were not included in cycle 1 (2007-2009).

E Use data with caution.

F Data is too unreliable to be published.

Table 10.5.3 - Mercury (inorganic) (creatinine adjusted) - Geometric means and selected percentiles of urine concentrations (μg/g creatinine) for the Canadian population aged 3-79 years by age group, Canadian Health Measures Survey cycle 1 (2007-2009), cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 5694 50.42 - <LOD <LOD 1.0 (0.94-1.1) 1.6 (1.3-1.9)
4 (2014-2015) 5594 56.35 - <LOD <LOD 0.94 (0.78-1.1) 1.5 (1.2-1.8)
Males, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 2842 49.37 - <LOD 0.21 (<LOD-0.24) 0.86 (0.63-1.1) 1.2 (1.1-1.4)
4 (2014-2015) 2808 55.68 - <LOD <LOD 0.82 (0.61-1.0) 1.3 (1.0-1.6)
Females, 3-79 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 2852 51.47 - <LOD <LOD 1.2 (0.87-1.5) 1.9 (1.5-2.3)
4 (2014-2015) 2786 57.04 - <LOD <LOD 1.1 (0.85-1.3) 1.7 (1.3-2.1)
3-5 years
1 (2007-2009)Footnote b - - - - - - -
3 (2012-2013) 519 74.81 - <LOD <LOD 0.73Footnote E (<LOD-1.0) 1.0 (0.72-1.3)
4 (2014-2015) 512 83.98 - <LOD <LOD 0.46 (<LOD-0.56) 0.72Footnote E (0.46-0.99)
6-11 years
1 (2007-2009) 1025 66.05 - <LOD <LOD 1.3Footnote E (0.62-1.9) 2.0 (1.3-2.7)
3 (2012-2013) 1010 61.29 - <LOD <LOD 0.99Footnote E (0.55-1.4) 1.9Footnote E (0.84-3.0)
4 (2014-2015) 1007 69.94 - <LOD <LOD 0.58Footnote E (0.32-0.84) 1.3 (0.83-1.7)
12-19 years
1 (2007-2009) 975 57.54 - <LOD <LOD 0.79 (0.55-1.0) 1.3Footnote E (0.79-1.8)
3 (2012-2013) 997 59.58 - <LOD <LOD 0.42Footnote E (0.27-0.58) 0.73Footnote E (0.42-1.0)
4 (2014-2015) 988 65.49 - <LOD <LOD 0.33 (0.27-0.40) 0.52 (0.35-0.70)
20-39 years
1 (2007-2009) 1162 46.23 - <LOD 0.21 (0.18-0.24) 1.1 (0.89-1.4) 1.9 (1.5-2.2)
3 (2012-2013) 1048 45.13 - <LOD 0.22 (<LOD-0.26) 0.85 (0.56-1.2) 1.2 (0.97-1.3)
4 (2014-2015) 1057 50.99 - <LOD <LOD 0.66Footnote E (0.38-0.94) 0.92 (0.60-1.2)
40-59 years
1 (2007-2009) 1202 36.04 0.39 (0.33-0.48) <LOD 0.43 (0.33-0.52) 2.1 (1.5-2.7) 3.0 (2.3-3.7)
3 (2012-2013) 1079 36.20 0.33 (0.29-0.38) <LOD 0.33 (0.27-0.40) 1.3 (0.91-1.7) 1.7 (1.5-2.0)
4 (2014-2015) 1037 40.31 - <LOD 0.24 (0.21-0.27) 1.3 (0.93-1.8) 2.1Footnote E (1.1-3.1)
60-79 years
1 (2007-2009) 1068 45.69 - <LOD 0.29Footnote E (0.17-0.42) 2.0 (1.7-2.3) 2.7 (2.1-3.4)
3 (2012-2013) 1041 39.00 0.32 (0.28-0.36) <LOD 0.32 (0.27-0.37) 1.3 (0.95-1.6) 2.2 (1.6-2.8)
4 (2014-2015) 993 41.69 - <LOD 0.27 (0.23-0.31) 1.2 (1.1-1.4) 1.6 (1.4-1.9)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

b Data not available as participants under the age of 6 years were not included in cycle 1 (2007-2009).

E Use data with caution.

Table 10.5.4 - Methylmercury - Geometric means and selected percentiles of whole blood concentrations (μg/L) for the Canadian population aged 20-79 years by age group, Canadian Health Measures Survey cycle 3 (2012-2013) and cycle 4 (2014-2015).
Cycle n %<LODFootnote a GM (95% CI) 10th (95% CI) 50th (95% CI) 90th (95% CI) 95th (95% CI)
Total, 20-79 years
3 (2012-2013) 1032 18.70 0.69 (0.52-0.91) <LOD 0.78 (0.54-1.0) 3.3Footnote E (1.3-5.3) 5.6Footnote E (2.9-8.2)
4 (2014-2015) 1043 18.12 0.59 (0.51-0.68) <LOD 0.57 (0.45-0.68) 2.8 (1.9-3.7) 4.1 (3.5-4.6)
Males, 20-79 years
3 (2012-2013) 502 18.33 0.68Footnote E (0.41-1.1) <LOD 0.68Footnote E (0.26-1.1) 4.6Footnote E (1.3-7.8) 8.1Footnote E (4.2-12)
4 (2014-2015) 512 18.16 0.62 (0.53-0.71) <LOD 0.56 (0.41-0.71) 2.9 (1.9-4.0) 4.0 (3.2-4.8)
Females, 20-79 years
3 (2012-2013) 530 19.06 0.70 (0.58-0.85) <LOD 0.89 (0.74-1.0) 2.8Footnote E (1.4-4.1) 4.7Footnote E (3.0-6.4)
4 (2014-2015) 531 18.08 0.57 (0.46-0.70) <LOD 0.57 (0.43-0.72) 2.5Footnote E (0.99-4.0) 4.4 (3.2-5.7)
20-39 years
3 (2012-2013) 359 24.51 0.61 (0.45-0.82) <LOD 0.65 (0.42-0.87) Footnote F 5.0Footnote E (1.9-8.1)
4 (2014-2015) 361 25.76 0.42 (0.34-0.52) <LOD 0.48 (0.35-0.61) 1.8 (1.4-2.2) 2.2 (1.7-2.6)
40-59 years
3 (2012-2013) 313 19.17 0.65Footnote E (0.44-0.96) <LOD 0.71Footnote E (0.27-1.2) 3.2Footnote E (0.85-5.5) 5.8Footnote E (2.3-9.3)
4 (2014-2015) 316 17.41 0.66 (0.51-0.84) <LOD 0.56Footnote E (0.33-0.79) 3.7 (2.5-4.9) 4.3 (3.3-5.3)
60-79 years
3 (2012-2013) 360 12.50 0.94 (0.67-1.3) <LOD 1.0Footnote E (0.65-1.4) 3.4Footnote E (2.0-4.8) Footnote F
4 (2014-2015) 366 11.20 0.83 (0.63-1.1) <LOD 0.78Footnote E (0.49-1.1) 3.8 (2.7-5.0) 5.1 (3.3-6.9)

a If >40% of samples were below the LOD, the percentile distribution is reported but means were not calculated.

E Use data with caution.

F Data is too unreliable to be published.

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