Polybrominated diphenyl ethers in fish and sediment

Polybrominated diphenyl ethers in fish

Key results

From 2016 to 2018, fish sampling was conducted in 6 drainage regions in Canada. Concentrations for 4 subgroups of PBDE were analyzed.

• TriBDE, tetraBDE and hexaBDE concentrations were below the guidelines in all samples and all drainage regions
• PentaBDE concentrations were above the guidelines for at least 1 sample in each drainage region

PBDE subgroup concentrations in fish relative to guidelines by drainage regions, Canada, 2016 to 2018

How this indicator was calculated

Note: For the 2016 to 2018 period, samples were collected from the catch of 129 representative predatory fish (Lake Trout or Walleye) collected in 6 drainage regions. See the drainage region map. 
Source: Environment and Climate Change Canada (2019) Chemical Management Plan Monitoring and Surveillance.

The results of the 2016 to 2018 sampling campaign are similar to the 2013 to 2015 sampling campaign. The 2016 to 2018 campaign found concentrations of triBDE, tetraBDE and hexaBDE below the guidelines in all drainage basins. The lower concentrations of tetraBDE in the Great Lakes represents an improvement compared to the 2013 to 2015 sampling campaign.

PentaBDE concentrations were above the guidelines for all the samples from the Great Lakes and the St. Lawrence drainage regions. In the other 4 drainage regions, pentaBDE concentrations remained below the guidelines for some of the samples.

Trends in PBDE concentrations in fish in Lake Ontario

Sufficient data are available to present concentration trends in fish in Lake Ontario only. There are insufficient data from other Canadian water bodies to determine trends.

PentaBDE in fish in Lake Ontario

Key results

• Since 1997, the concentrations of pentaBDE in Lake Trout collected from Lake Ontario have declined at an average annual rate of 4.8%
• Despite the decline, levels of pentaBDE in fish were still above the guideline

PentaBDE concentrations in Lake Trout from Lake Ontario, Canada, 1997 to 2018

How this indicator was calculated

Note: PentaBDE concentrations are expressed as an annual geometric average in this chart. A downward statistical trend is detected at the 95% confidence level for the time series. In 2013, Environment and Climate Change Canada published Federal Environmental Quality Guidelines for PBDEs to assess the ecological significance of levels of PBDEs in the environment.
Source: Environment and Climate Change Canada (2019) National Fish Contaminants Monitoring and Surveillance Program.

TetraBDE in fish in Lake Ontario

Key results

• Since 1997, the concentrations of tetraBDE in Lake Trout collected from Lake Ontario have declined at an average annual rate of 7.7%
• Since 2004, levels of tetraBDE in fish are below the guideline

TetraBDE concentrations in Lake Trout from Lake Ontario, Canada, 1997 to 2018

How this indicator was calculated

Note: TetraBDE concentrations are expressed as an annual geometric average in this chart. A downward statistical trend is detected at the 95% confidence level for the time series. In 2013, Environment and Climate Change Canada published Federal Environmental Quality Guidelines for PBDEs to assess the ecological significance of levels of PBDEs in the environment.
Source: Environment and Climate Change Canada (2019) National Fish Contaminants Monitoring and Surveillance Program.

Polybrominated diphenyl ethers in sediment

Key results

From 2007 to 2018, sediment sampling was conducted in 12 drainage regions in Canada. Concentrations for 6 subgroups of PBDE were analyzed.

• TriBDE, hexaBDE and octaBDE concentrations were below the guidelines in all samples and all drainage regions
• Concentrations were above the guidelines for at least 1 sample
  o    in 1 drainage region for tetraBDE
  o    in 8 drainage regions for pentaBDE
  o    in 3 drainage regions for decaBDE

PBDE subgroup concentrations in sediment relative to guidelines by drainage regions, Canada, 2007 to 2018

How this indicator was calculated

Note: The figure presents only the PBDE subgroups (tetraPBDE, pentaBDE and decaBDE) for which at least 1 sample collected returned a concentration reading above the guideline. Measurements were made in 549 surface sediment samples collected in 12 drainage regions between 2007 and 2018.
Source: Environment and Climate Change Canada (2019) Chemical Management Plan Monitoring and Surveillance.

Only the Great Lakes drainage region had concentrations above the guidelines for tetraBDE (2015 to 2016 sampling).

The analysis found that sediment samples from the Pacific Coastal, Fraser-Lower Mainland, Okanagan-Similkameen, Lower Saskatchewan-Nelson, Great Lakes, St. Lawrence, Saint John-St. Croix and Maritime Coastal drainage regions had pentaBDE concentrations above the guidelines. PentaBDE concentrations exceeded the guidelines for 34% of the sediment samples analyzed.

Sediment samples from the Great Lakes, St. Lawrence and Fraser-Lower Mainland drainage regions had decaBDE concentrations above the guideline.

Polybrominated diphenyl ethers in sediment in Lake St. Pierre

Sediment sampling in many drainage regions of Canada does not go back far enough to establish long-term trends. However, data collected in Lake St. Pierre between 2003 and 2013 were sufficient to determine a trend in pentaBDE concentrations in sediment.

Key results

• Sediments collected in 2003 and 2013 at Lake St. Pierre, part of the St. Lawrence drainage region, show a 59% decrease in the concentrations of pentaBDE^{Footnote 2}

PentaBDE concentrations in sediments from Lake St. Pierre, Canada, 2003 and 2013

How this indicator was calculated

Note: The Federal Environmental Quality Guideline in sediment for pentaBDE (congener BDE-99) is 0.4 nanograms per gram (ng/g) of dry weight and is shown in yellow on this map. The concentration values are shown in orange when they are twice the value of the guidelines and in red when they are 4 times or more above the guideline. Concentrations below the guideline value are expressed in green (if the values are half the guideline) or in blue if the values are well below half the guideline. Points represent the sampling sites.
Source: Environment and Climate Change Canada (2018) Sediment quality status of Lake Saint-Pierre in 2013. Monitoring changes in the state of the St. Lawrence.

The overall average concentration of pentaBDE decreased from 0.87 ng/g to 0.36 ng/g in Lake St. Pierre over a 10‑year period. Given domestic and international risk management for PBDEs, this downward trend is expected to continue.

About the indicators

What the indicators measure

These indicators identify the drainage regions where concentrations are below or above the Federal Environmental Quality Guidelines (the guidelines) for polybrominated diphenyl ethers (PBDEs) in fish and sediment. The guidelines were developed under the Chemicals Management Plan and are used in this report to evaluate whether, and the degree to which, concentrations in the environment exceed the guidelines.

Why these indicators are important

These indicators provide information on the presence of PBDEs in the environment and on the progress of strategies and policies to reduce or control their occurrence in the environment.

Polybrominated diphenyl ethers (PBDEs) are commonly used as additive flame retardants, added to materials (or products) for flame resistance. Since PBDEs are not chemically linked to the products in which they are used, they are slowly and consistently released throughout the production, use and disposal stages of the products.

TetraBDE, pentaBDE and hexaBDE subgroups can bioaccumulate over time in certain organisms such as fish. These substances have a tendency to biomagnify through food webs, potentially resulting in high concentrations in animals, such as predatory fish, birds and mammals. PBDEs may break down in the environment or within organisms from higher (decaBDE) to less brominated PBDEs (pentaBDE).

Polybrominated diphenyl ethers are persistent organic pollutants and they have been managed under the Chemicals Management Plan. Currently, the use of PBDEs is declining because most commercial mixtures containing these chemicals have either been voluntarily phased out by manufacturers or are subject to prohibition in Canada.

The PBDEs that were assessed have been declared "toxic" as defined by the Canadian Environmental Protection Act, 1999. Among the PBDE subgroups that were assessed, tetraBDE, pentaBDE and hexaBDE were found to meet the criteria for virtual elimination under the act. As a result, the Government has prohibited the manufacture, import, use and sale of tetraBDE, pentaBDE, hexaBDE, heptaBDE, octaBDE, nonaBDE, decaBDE, and all products that contain such PBDEs, with a limited number of exemptions, to minimize their release in the environment.

The PBDEs found in the Canadian environment are not only from domestic sources but also from international sources since PBDEs may be suspended in air and transported over long distances. As such, Canada is a party to 2 international agreements that target the elimination of the production, use, import and export of PBDEs: the global Stockholm Convention on Persistent Organic Pollutants under the United Nations Environment Programme and the regional Protocol on Persistent Organic Pollutants to the Convention on Long-range Transboundary Air Pollution under the United Nations Economic Commission for Europe. Canada is also a party to the Rotterdam Convention, the aim of which is to minimize PBDEs in the environment.

Long-range transport of PBDEs to Canada, presence in certain products, widespread use in the past and slow breakdown following release means that PBDEs still remain in the environment across Canada. Current human exposure to PBDEs is well below levels that are considered to be of concern.

Safe and healthy communities

These indicators support the measurement of progress towards the following 2019 to 2022 Federal Sustainable Development Strategy long-term goal: All Canadians live in clean, sustainable communities that contribute to their health and well-being.

Related indicators

The Perfluorooctane sulfonate (PFOS) in fish and water indicators identify the drainage regions where concentrations of PFOS in fish and water are above the Federal Environmental Quality Guidelines.

Data sources and methods

Data sources

The polybrominated diphenyl ethers (PBDEs) environmental concentration data were obtained from Environment and Climate Change Canada's Chemical Management Plan Monitoring and Surveillance Activities.

More information

The sampling locations for fish and sediment varied throughout the reporting years. Data for fish and sediments were gathered in as many drainage regions as permitted by program capacity in any year. To provide a better representation of each drainage region, the samples used to calculate the indicators for fish, were collected during the most recent sampling campaign (from 2016 to 2018). Data from the previous campaign (from 2013 to 2015) were also presented for comparison, when possible. For sediment, all samples available from 2007 to 2018 were used to calculate the indicators.

There is a time lag of 1.5 to 2 years between the sampling date and publication of the indicators. This time lag is due to the time required to perform the monitoring, to compile the data, to validate (that is, perform quality assurance and control), analyze, review and report on the indicators, and to ensure enough recent data is available for comparison with past data or previous editions of the indicators.

Polybrominated diphenyl ethers are a group of chemicals containing 209 compounds. They are classified into 8 subgroups known as homologues, based on the number of bromine atoms they contain. For the PBDE in fish and sediment indicators, 4 of the 8 subgroups are considered in fish, and 6 of the 8 subgroups are considered in sediment.

Polybrominated diphenyl ether subgroups used in the indicators

Subgroup	Chemical group name	Fish	Sediment
triBDE	tribromodiphenyl ether	X	X
tetraBDE	tetrabromodiphenyl ether	X	X
pentaBDE	pentabromodiphenyl ether	X	X
hexaBDE	hexabromodiphenyl ether	X	X
octaBDE	octabromodiphenyl ether	-	X
decaBDE	decabromodiphenyl ether	-	X

Federal Environmental Quality Guidelines

The Federal Environmental Quality Guidelines (the guidelines) provide benchmarks for the quality of the ambient environment. Where the concentration of a given chemical is at or below the guidelines, there is low likelihood of direct adverse effects from the chemical on aquatic life exposed via the water or sediment, or where chemicals may bioaccumulate, in wildlife (birds and mammals) that consume aquatic life. The guidelines can serve 3 functions:

• aid in preventing pollution by providing targets for acceptable environmental quality
• assist in evaluating the significance of concentrations of chemical substances currently found in the environment (monitoring of water, sediment, and biological tissue)
• serve as performance measures of the success of risk management activities

The guidelines were developed under the Chemical Management Plan. Measured concentrations exceeding the guideline levels indicate the potential for aquatic organisms to be affected by PBDEs in those locations.

Federal Environmental Quality Guidelines for polybrominated diphenyl ethers

Subgroup[A]	Federal Environmental Quality Guideline for fish tissues (nanograms per gram wet weight)	Federal Environmental Quality Guideline for sediment[B] (nanograms per gram dry weight)
triBDE	120	44
tetraBDE	88	39
pentaBDE	1	0.4
hexaBDE	420	440
octaBDE	n/a	5 600[C]
decaBDE	n/a	19[C][D]

Note: n/a = not applicable. ^[A] The guidelines for triBDE, tetraBDE, hexaBDE and decaBDE are based on data for chemicals BDE-28, BDE-47, BDE-153 and BDE-209, respectively, unless otherwise noted. Congener-specific guidelines exist for BDE-99 and BDE-100. ^[B] Values normalized to 1% organic carbon. ^[C] Values adapted from the Ecological Screening Assessment Report. Sediment FEQGs for octa- and deca-BDE were adapted from the Ecological Screening Assessment Report by being corrected for the sediment organic carbon in the actual tests, and then normalized to 1% organic carbon instead of the 4% in the Ecological Screening Assessment Report. ^[D] Based on a mixture of decaBDE with some nonaBDE.

Spatial coverage

The PBDEs in fish and sediment indicators use water drainage regions as the geographical unit for the calculation of the national indicators. These drainage regions correspond to those defined in Statistics Canada's Standard Drainage Area Classification.

Geographic extent of the drainage regions used for the  indicators

Long description

The map of Canada shows all the drainage regions of the Chemicals Management Plan Monitoring and Surveillance Program used for the Polybrominated diphenyl ethers in fish and sediment indicators. Each drainage region shows its appropriate drainage number code. The drainage regions (in blue) are those that were used to calculate the indicators for the years 2016 to 2018 for fish and 2007 to 2018 for sediment. The regions included are Pacific Coastal (1), Fraser-Lower Mainland (2), Okanagan–Similkameen (3), Columbia (4), Yukon (5), Peace–Athabasca (6), Lower Mackenzie (7), South Saskatchewan (11), Lower Saskatchewan–Nelson (14), Churchill (15), Great Lakes (19), St. Lawrence (21), Saint John-St. Croix (23), Maritime Coastal (24) and Newfoundland–Labrador (25).

Methods

The Polybrominated diphenyl ethers (PBDE) in fish and sediment indicators are presented by drainage regions showing whether or not PBDE concentrations in fish and sediment have exceeded the Federal Environmental Quality Guidelines (the guidelines).

Recent changes

In this update, the tetraBDE concentrations in fish in Lake Ontario and its trend over the period from 1997 to 2018 has been added.

Twelve (12) samples have been attributed to a drainage region that differs from the one from the indicators' previous version.

Caveats and limitations

Monitoring and surveillance of PBDEs in lakes and rivers under the Chemicals Management Plan began in 2007 (except for Lake Ontario, which was initiated in the 1990s, and Lake St. Pierre, which was initiated in 2003).

Monitoring is not necessarily performed at the same location each year because of challenges in obtaining fish or sediment samples. These challenges include remoteness, shipping logistics and resource constraints. Given these challenges, a comparison from one year to the next at the national level is not yet possible. That is why the PBDEs in fish and sediment indicators are estimated by grouping the samples by drainage area for the periods from 2016 to 2018 for PBDEs in fish and from 2007 to 2018 for PBDEs in sediment.

Resources

References

Environment Canada (2010) Risk Management Strategy for Polybrominated Diphenyl Ethers (PBDEs). Retrieved on September 26, 2019.

Environment Canada (2011) Environmental Monitoring and Surveillance in Support of the Chemicals Management Plan. Retrieved on September 26, 2019.

Environment Canada (2011) Polybrominated Diphenyl Ethers in the Canadian Environment. Retrieved on September 26, 2019.

Environment Canada (2012) Canada's National Aquatic Biological Specimen Bank and Database. Retrieved on September 26, 2019.

Environment Canada (2013) Federal Environmental Quality Guidelines (FEQGs). Retrieved on September 26, 2019.

Environment and Climate Change Canada (2018) Sediment quality status of Lake Saint-Pierre in 2013. Monitoring changes in the state of the St. Lawrence. Retrieved on September 26, 2019.