Archived The Canadian House Dust Study

The Canadian House Dust Study is a national-scale research study of chemicals in house dust, conducted by Health Canada. The study was designed to provide statistically representative national baseline concentrations of metals and organic substances in indoor dust sampled from urban homes.

Sampling for the Canadian House Dust Study was conducted between 2007 and 2010 and included vacuum sampling and wipe sampling of 1025 homes.

The house dust samples were analyzed for a variety of inorganic and organic substances. Organic compounds in house dust come from consumer products including plasticizers (phthalates, bisphenol A, BPA analogues); flame retardants (organophosphates and halogenated compounds); surfactants, bactericides (parabens); insecticides (DDT); lubricants/stabilizers; disinfectants; and fragrances. Metals, such as lead and zinc, have both indoor and outdoor sources. In fact, some metals may have elevated concentrations in indoor dust compared to garden soil or street dust.

The results provided us with a better understanding of the background levels of chemicals that Canadians may be exposed to in their homes.

In 2022, Health Canada published a study that combined all the dust chemistry datasets with information about the Canadian House Dust Study homes, such as house age, heating style, construction materials, floor coverings and environmental setting, to identify national trends. This study also summarized the results for all inorganic and organic chemicals measured in the Canadian House Dust Study to date. It was published in the International Journal of Environmental Research and Public Health.

The Canadian House Dust Study samples were further used to detect microbes of specific concern to human health (e.g. incidence of botulism spores in the household dust of major Canadian cities).

Results for Lead in House Dust

Exposures to lead (Pb) can be harmful to the health of Canadians of all ages, but young children and the developing fetus are especially vulnerable. Small children and toddlers can become exposed to lead when they accidentally ingest house dust through normal hand-to-mouth activities. Therefore, a priority of the Canadian House Dust Study was to provide nationally representative dust lead concentrations and dust lead loadings (the amount of lead deposited in dust on a given surface area) in urban homes. The results were published in the journal Science of the Total Environment.

The vacuum sampling method showed that all 1025 urban Canadian homes sampled had measurable concentrations of lead in their house dust. Dust lead concentrations in most homes ranged between 42 and 760 micrograms per gram (µg/g). A large proportion of the wipe sampling measurements did not detect any lead. However, the wipe method provided useful information about differences in lead loadings between rooms in the same home. These differences reflect the different activities conducted in each room.

These nationally representative baseline values for dust lead concentrations and dust lead loadings provide useful information for risk assessment and management of lead. Population-based percentile values can help to identify increased levels of exposure to lead in indoor environments. For example, in the Canadian House Dust Study, the 95^th percentile dust lead concentration was 760 µg/g. This meant that only 5% of the study homes had dust lead concentrations higher than 760 µg/g (= 'parts per million' or ppm). Possible sources of elevated lead in house dust included lead-based paint, construction materials such as solder, or contaminated soil that was tracked-in from outdoors.

The 2013 study showed that dust lead loading is strongly influenced by the amount of house dust that accumulates on the floor (the dust mass). The observation that dust mass is the overriding influence on lead loading is consistent with previous studies of urban communities in the United States. These results support Health Canada's recommendation to keep dust levels in the home at a minimum, in order to reduce childhood exposures to lead (Health Canada, 2016).

Recently, Health Canada collaborated with the United States Environmental Protection Agency (US EPA) to create a North American-wide residential lead data set, by combining lead data from the Canadian House Dust Study with smaller U.S. lead data sets. This study was published in 2021.

The above paper describes how the Canadian House Dust Study supported the recent revision of the US EPA residential lead-loading guideline to 10 μg/ft² for floors. It should be noted that results for 94% of Canadian homes fell below this guideline (10 μg/ft² = 107.6 micrograms per square metre) (Rasmussen et al. 2013).

Results for Other Metals in House Dust

The Canadian House Dust Study provided nationally representative baseline values for a total of 62 elements in house dust, expressed as both concentrations and loadings. These baseline values have helped Health Canada to estimate general population exposures to metals, as well as exposures of vulnerable populations, especially children (e.g. screening assessment reports for aluminum, thallium, titanium, copper, zinc).

The table below summarizes the 50^th percentile (median) and 95^th percentile values for concentrations and loadings of all 62 elements measured in the Canadian House Dust Study. The concentrations were measured on dust samples that were sieved to a particle size smaller than 80 microns. The loadings were calculated using the mass of dust particles smaller than 300 microns to allow direct comparisons with wipe sample results. These urban baseline percentiles may be used as dust screening values, and may provide a point-of-comparison for local residential studies.

More Information on the Canadian House Dust Study

Detailed results of the Canadian House Dust Study are provided in the following scientific journal articles:

• McDonald, L.T., Rasmussen, P.E., Chénier, M., Levesque, C. (2010) Wipe Sampling Methodologies To Assess Exposure To Lead And Cadmium In Urban Canadian Homes. In Proceedings of 25th Annual International Conference on Soils, Sediments, Water and Energy, University of Massachusetts, Amherst, USA, October 19-22, 2009, Vol. 15 (Article 6). available at: http://scholarworks.umass.edu/soilsproceedings/vol15/iss1/6
• Fan, X., Kubwabo, C., Rasmussen, P.E., Jones-Otazo, H. (2010) Simultaneous Quantitation of Parabens, Triclosan, and Methyl Triclosan in Indoor House Dust Using Solid-Phase Extraction and GC/ITMS. J. Environ. Monit. 12: 1891–1897. DOI: 10.1039/c0em00189a
• MacLean, L.C.W., Beauchemin, S., and Rasmussen, P.E. (2010) Application of Synchrotron X-Ray Techniques for the Determination of Metal Speciation in (House) Dust Particles. In Urban Airborne Particulate Matter: Origins, Chemistry, Fate and Health Impacts. (Eds. F. Zereini and C. Wiseman) Springer Publ. Ltd. 17p with illustrations. Springer-Verlag, Berlin. Part II, pp 193-216.
• MacLean, L.C.W, Beauchemin, S., and Rasmussen, P.E. (2011) Lead speciation in house dust from Canadian urban homes using EXAFS, micro-XRF and micro-XRD. Environ. Sci. Technol. 45: 5491–5497. https://doi.org/10.1021/es2001503
• Rasmussen, P.E., Beauchemin, S., Chénier, M., Levesque, C., MacLean, L.C.W., Marro, L., Jones-Otazo, H., Petrovic, S., McDonald, L.T., Gardner, H.D. (2011) Canadian House Dust Study: Lead Bioaccessibility and Speciation. Environ. Sci. Technol. 45: 4959–4965. https://doi.org/10.1021/es104056m
• McDonald, L.T., Rasmussen, P.E., Chénier, M., and Levesque, C. (2011) Extending Wipe Sampling Methodologies to Elements Other Than Lead. J. Environ. Monit. 13: 377-383. https://doi.org/10.1039/C0EM00440E
• Kubwabo, C., Fan, X., Rasmussen, P.E., Wu, F. (2012) Determination of synthetic musk compounds in indoor house dust by gas chromatography–ion trap mass spectrometry. Anal. Bioanal. Chem. 404: 467-477. DOI: 10.1007/s00216-012-6124-2
• Rasmussen, P.E., Woldemichael, M., Lalonde, A. et al. (2012) Dust, In Imperfect Health: The Medicalization Of Architecture, Book accompanying CCA exhibition, 25 October 2011 – 1 April 2012. (Eds. Mirko Zardini and Giovanna Borasi), Published by Canadian Centre for Architecture and Lars Müller, Montreal, Canada. pp: 160-163.
• Kubwabo, C., Rasmussen, P.E., Fan, X., Kosarac, I., Wu, F., Zidek, A., Kuchta, S.L. (2013) Analysis of selected phthalates in Canadian indoor dust collected using household vacuum and standardized sampling techniques. Indoor Air 23: 506-514. DOI: 10.1111/ina.12048
• Kubwabo, C., Fan X., Rasmussen, P.E., Wu, F. (2013) A national survey of organophosphate ester flame retardants in Canadian house dust. Organohalogen Compounds 75: 724-727.
• Rasmussen, P.E., Levesque, C., Chénier, M., Gardner, H.D., Jones-Otazo, H., Petrovic, S. (2013) Canadian House Dust Study: Population-based concentrations, loads and loading rates of arsenic, cadmium, chromium, copper, nickel, lead, and zinc inside urban homes. Sci. Total. Environ. 443: 520–529. https://doi.org/10.1016/j.scitotenv.2012.11.003
• MacLean, L.C.W., Beauchemin, S., and Rasmussen, P.E. (2013) Chemical transformations of lead compounds under humid conditions: implications for bioaccessibility. Environ. Geochem. Health 35: 153-159. DOI: 10.1007/s10653-012-9467-x
• Beauchemin, S., Rasmussen, P.E., McKinnon, T., Chénier, M., Boros, K. (2014) Zinc in House Dust: Speciation, Bioaccessibility and Impact of Humidity. Environ. Sci. Technol. 2014: 9022−9029. https://doi.org/10.1021/es5018587
• Rasmussen, P.E., Beauchemin, S., Maclean, L.C.W., Chénier, M., Levesque, C. and Gardner, H.D. (2014) Impact of humidity on speciation and bioaccessibility of Pb, Zn, Co and Se in house dust. J. Anal. At. Spectrom. 29: 1141–1308. https://doi.org/10.1039/C4JA00058G
• Fan, X., Kubwabo, C., Rasmussen, P.E., Wu, F. (2014) Simultaneous determination of thirteen organophosphate esters in settled indoor house dust and a comparison between two sampling techniques (2014) Sci. Total Environ. 491–492: 80–86. DOI: 10.1016/j.scitotenv.2013.12.127
• Kubwabo, C., Rasmussen, P.E., Fan, X., Kosarac, I., Grenier, G., Coleman, K. (2016) Simultaneous quantification of bisphenol A, alkylphenols and alkylphenol ethoxylates in indoor dust and a comparison between two sampling techniques. Anal. Methods 8: 4093-4100. https://doi.org/10.1039/C6AY00774K
• Kubwabo, C., Fan, X., Rasmussen, P.E. (2016) Expanding the number of phthalates monitored in house dust. Int. J. Environ. Anal. Chem. 96: 667-681. https://doi.org/10.1080/03067319.2016.1180380
• Fan, X., Kubwabo, C., Rasmussen, P.E., Wu, F. (2016) Non-PBDE halogenated flame retardants in Canadian indoor house dust: sampling, analysis, and occurrence. Environmental Science and Pollution Research. Environ. Sci. Pollut. Res. 23: 7998-8007. DOI: 10.1007/s11356-015-5956-7
• Rasmussen, P.E., Gardner, H.D., Levesque, C., Chénier, M. (2017) Rare Earth Elements and Select Actinoids in the Canadian House Dust Study. Indoor Air 27: 965-976. DOI: 10.1111/ina.12379
• Kubwabo, C., Rasmussen, P.E., Grenier, G. (2017) Occurrence of selected pesticides in Canadian house dust. Organohalogen Compounds, 79: 175-178.
• Rasmussen, P.E., Levesque, C., Chénier, M., Gardner, H.D. (2018) Contribution of metals in resuspended dust to indoor and personal inhalation exposures: relationships between PM10 and settled dust. Build. Environ. 143: 513-522. doi.org/10.1016/j.buildenv.2018.07.044
• Fan, X., Kubwabo, C., Wu, F, Rasmussen, P.E. (2019) Analysis of Bisphenol A, Alkylphenols and Alkylphenol Ethoxylates in NIST SRM 2585 and Indoor House Dust by Gas Chromatography-Tandem Mass Spectrometry (GC/MS/MS). J. AOAC Int. 102: 246-254. DOI: 10.5740/jaoacint.18-0071
• Shang, H., Fan, X., Kubwabo, C., Rasmussen, P.E. (2019) Short-chain and medium-chain chlorinated paraffins in Canadian House Dust Study and NIST SRM 2585. Environ. Sci. Pollut. Res. 26: 7453-7462. https://doi.org/10.1007/s11356-018-04073-2
• Kastury, F., Ritch, S., Rasmussen, P.E., Juhasz, A.L. (2020) Influence of household smoking habits on inhalation bioaccessibility of trace elements and light rare earth elements in Canadian house dust. Environ. Pollut. 262: 114132. DOI: 10.1016/j.envpol.2020.114132
• Bevington, C., Gardner, H.D., Cohen, J., Henning, C., Rasmussen, P.E. (2021) Relationship between Residential Dust-Lead Loading, and Dust-Lead Concentration across Multiple North American Datasets. Build. Environ. 188: 107359. doi.org/10.1016/j.buildenv.2020.107359
• Fan, X., Katuri, G.P. Caza, A., Rasmussen, P.E., Kubwabo, C. (2021) Simultaneous measurement of 16 bisphenol analogues in house dust and evaluation of two sampling techniques. Emerg. Contam. 7: 1-9. https://doi.org/10.1016/j.emcon.2020.12.001
• Kubwabo, C., Fan, X., Katuri, G.P., Habibagahi, A., Rasmussen, P.E. (2021) Occurrence of Aryl and Alkyl-Aryl Phosphates in Canadian House Dust. Emerg. Contam. 7: 149-159. https://doi.org/10.1016/j.emcon.2021.07.002
• Levesque, C., Wiseman, C.L., Beauchemin, S., Rasmussen, P.E. (2021) Thoracic fraction (PM10) of resuspended urban dust: Geochemistry, particle size distribution and lung bioaccessibility Geosci. 11:87. https://doi.org/10.3390/geosciences11020087
• Levesque, C., Rasmussen, P.E. (2022) Determination of total mercury and carbon in a national baseline study of urban house dust. Geosci. 12: 52. https://doi.org/10.3390/geosciences12020052
• Rasmussen, P.E., Kubwabo, C., Gardner, H.D., Levesque, C., Beauchemin, S. (2022) Relationships between house characteristics and exposures to metal(loid)s and synthetic organic contaminants evaluated using settled indoor dust. Int. J. Environ. Res. Public Health 19: 10329. DOI: 10.3390/ijerph191610329
• Harris, R.A, Blondin-Brosseau, M., Levesque, C., Rasmussen, P.E., Beauchemin, S., Austin J.W. (2023) Viable C. botulinum spores not detected in the household dust of major Canadian cities. Epidemiol. Infect. 7: 1-21. DOI: 0.1017/S0950268823001474
• Beauchemin, S., Avramescu, M.-L., Levesque, C., Rasmussen, P.E. (2024) Carcinogenic metal(loid)s in house dust compared to soil: concentration and gastric bioaccessibility. Environ. Res. 255: 119175. https://doi.org/10.1016/j.envres.2024.119175

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