Polybrominated diphenyl ethers in fish and sediment

Polybrominated diphenyl ethers (PBDEs), a group of chemicalsFootnote [1] used as additive flame retardants, are of concern for wildlife. PBDEs build up in living organisms, and remain in the environment for long periods after their release. The PBDEs in Fish and Sediment indicators report on the occurrence of PBDE concentrations above or below Federal Environmental Quality Guidelines (FEQGs) in fish tissue and sediment. FEQGs are numerical limits established under the Chemicals Management Plan (CMP) to protect aquatic life, and therefore concentrations below the guidelines are not of concern; concentrations above guidelines indicate that further evaluation may be required.

PBDEs are persistent organic pollutants (POPs), and are considered high-priority chemicals under the CMP. 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 restrictions in Canada. The Government of Canada has developed a Risk Management Strategy for PBDEs with the objective of minimizing their release into the Canadian environment. This includes prohibition of the manufacture of tetraBDE, pentaBDE, hexaBDE, heptaBDE, octaBDE, nonaBDE and decaBDE; in addition, the use, sale, offer for sale, and import of tetraBDE, pentaBDE and hexaBDE is prohibited.

Canada is a party to two international agreements that restrict and ultimately target the elimination of the production, use, trade, release and storage of PBDEs: the Stockholm Convention on Persistent Organic Pollutants and the Protocol on Persistent Organic Pollutants of the United Nations Convention on Long-range Transboundary Air Pollution. Canada is also a party to the Rotterdam Convention, an international agreement that obligates parties to apply the prior informed consent procedure for international trade of certain PBDEs. The objective of these international agreements is to protect human health and the environment.

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

PBDEs in fish tissue

Between 2011 and 2012, Environment Canada conducted fish sampling in 10 drainage regions and analyzed PBDE concentrations in fish tissue of four subgroups for which guidelines have been set: triBDE, tetraBDE, pentaBDE and hexaBDE.

The following table indicates, for each PBDE subgroup (triBDE, tetraBDE, pentaBDE and hexaBDE), drainage regions where no fish samples returned a concentration reading above the guideline and drainage regions where at least one fish sample returned a concentration reading above the guideline, for the period 2011 to 2012.

The guideline was exceeded in seven of the ten drainage regions for pentaBDE, whereas the guideline for triBDE, tetraBDE and hexaBDE were not exceeded for any of the drainage regions. In two cases, for the drainages regions of Lower Mackenzie and Lower Saskatchewan-Nelson, where the pentaBDE guideline was not exceeded, the situation seems to have improved compared to the 2008-2010 samplings. It also seems to have improved for the Great Lakes drainage region for tetraBDE compared to the 2008-2010 samplings.

Table 1: Comparison between PBDE subgroup concentrations in fish against the guidelines, 2011 to 2012
Sampled drainage region triBDE tetraBDE pentaBDE hexaBDE
Columbia (4) No No Yes No
Yukon (5) No No Yes No
Peace-Athabasca (6) No No Yes No
Lower Mackenzie (7) No No NoFootnote [A] No
Assiniboine-Red (12) No No Yes No
Lower Saskatchewan-Nelson (14) No No NoFootnote [A] No
Churchill (15) No No Yes No
Great Lakes (19) No NoFootnote [A] Yes No
St. Lawrence (21) No No Yes No
Maritime Coastal (24) No No No No
Data for this table
Detailed data for Table 1: Comparison between PBDE subgroup concentrations in fish against the guidelines, 2011 to 2012
Sampling period Sampled drainage region Sample size Number of samples where triBDE concentration exceeded guideline Number of samples where tetraBDE concentration exceeded guideline Number of samples where pentaBDE concentration exceeded guideline Number of samples where hexaBDE concentration exceeded guideline
2011-2012 Columbia (4) 19 0 0 19 0
2011-2012 Yukon (5) 19 0 0 11 0
2011-2012 Peace-Athabasca (6) 20 0 0 13 0
2011-2012 Lower Mackenzie (7) 10 0 0 0 0
2011-2012 Assiniboine-Red (12) 10 0 0 6 0
2011-2012 Lower-Saskatchewan-Nelson (14) 22 0 0 0 0
2011-2012 Churchill (15) 30 0 0 28 0
2011-2012 Great Lakes (19) 89 0 0 89 0
2011-2012 St. Lawrence (21) 18 0 0 18 0
2011-2012 Maritime Coastal (24) 10 0 0 0 0
2008-2010 Pacific Coastal (1) 19 0 0 1 0
2008-2010 Columbia (4) 26 0 0 26 0
2008-2010 Yukon (5) 40 0 0 16 0
2008-2010 Peace-Athabasca (6) 44 0 0 36 0
2008-2010 Lower Mackenzie (7) 29 0 0 4 0
2008-2010 Assiniboine-Red (12) 24 0 0 16 0
2008-2010 Lower Saskatchewan-Nelson (14) 53 0 0 20 0
2008-2010 Churchill (15) 80 0 0 58 0
2008-2010 Great Lakes (19) 149 0 6 149 0
2008-2010 St. Lawrence (21) 30 0 0 30 0
2008-2010 Maritime Coastal (24) 28 0 0 0 0

Download data file (Excel/CSV; 1.46 KB)

Note: Measurements were made in 247 representative predatory fish (Lake Trout, Walleye, Cutthroat Trout, Rainbow Trout or Brook Trout) collected from 10 drainage regions from 2011 to 2012. "No" means no sample collected in the drainage region returned a concentration reading above the guideline. "Yes" means at least one sample collected in the drainage region returned a concentration reading above the guideline. Data from previous reporting measurements (2008-2010) for this indicator are also reported in the data table for this indicator.
Source: Environment Canada (2014) National Fish Contaminants Monitoring and Surveillance Program.

PBDE trends in fish in Lake Ontario

To provide context on changes through time, additional data showing pentaBDE concentrations in Lake Ontario fish are presented for the period 1997 to 2012. Since 1997, the concentrations of pentaBDE in Lake Trout collected from Lake Ontario have declined at an annual rate of 4.5%. Despite this decline, levels of pentaBDE in fish were still above the guideline in the most recent years of monitoring. Currently, there is insufficient data to determine the trends of PBDE concentrations in fish from other Canadian drainage regions.

PentaBDE concentrations in Lake Trout from Lake Ontario, 1997 to 2012

chart

Long description

The chart shows the annual geometric average concentration, expressed as nanograms of pentabromodiphenyl ether per gram of wet weight in Lake Trout from Lake Ontario from 1997 to 2012. Since 1997, the concentrations of pentabromodiphenyl ether have declined in Lake Trout collected from Lake Ontario at an average annual rate of 4.5%. Despite this decline, levels of pentaBDE in fish were still above the Federal Environmental Quality Guideline (one nanogram of pentabromodiphenyl ether per gram of fish wet weight) in the most recent years of monitoring.

Data for this chart
Data for PentaBDE concentrations in Lake Trout from Lake Ontario, 1997 to 2012
Year Number of samples Average concentration
(nanograms per gram wet weight)
1997 4 38
1998 4 30
1999 8 32
2000 7 39
2001 4 23
2002 4 31
2003 8 28
2004 8 23
2005 12 26
2006 14 24
2007 11 26
2008 24 28
2009 24 21
2010 10 28
2011 10 16
2012 10 17

Download data file (Excel/CSV; 515 B)

Note: PentaBDEs are expressed in annual geometric average in this chart. A trend line is reported only when a statistical trend is detected at the 95% confidence level. Other PBDEs sampled are triBDE, tetraBDE, hexaBDE, heptaBDE, octaBDE, nonaBDE and decaBDE. In 2010, Environment Canada developed Federal Environmental Quality Guidelines (FEQGs) for PBDEs to assess the ecological significance of levels of PBDEs in the environment.
Source: Environment Canada (2014) National Fish Contaminants Monitoring and Surveillance Program.

PBDEs in sediment

Between 2009-2010 and 2013-2014, Environment Canada conducted sediment sampling in nine drainage regions, and analyzed sediment concentrations for six subgroups of PBDEs having guidelines (see Table 2). The analysis found that sediment samples from the Pacific Coastal, Okanagan-Similkameen, Lower Saskatchewan-Nelson, Great Lakes, St. Lawrence and Maritime Coastal drainage regions had pentaBDE concentrations above the FEQG. Only the Newfoundland-Labrador, Columbia and the Assiniboine-Red drainage regions were below the FEQG for pentaBDE. Sediment from the St. Lawrence and Pacific Coastal drainage regions had concentrations above the guideline level for decaBDE. All other subgroups of PBDEs were below the guidelines for the regions where sampling occurred. In one case, for the Great Lakes drainage region, where the decaBDE guideline was not exceeded the situation seems to have improved compared to the samples of 2007 to 2011. In two drainage regions, Okanagan-Similkameen and the Maritime Coastal, where the pentaBDE guideline was exceeded the situation seems to have worsened compared to the samples of 2007 to 2011.

Table 2: Comparison between PBDE subgroup concentrations in sediment against the guidelines, 2009 to 2014
Sampled drainage region triBDE tetraBDE pentaBDE hexaBDE octaBDE decaBDE
Pacific Coastal (1) No No Yes No No Yes
Okanagan-Similkameen (3) No No YesFootnote [A] No No No
Columbia (4) No No No No No No
Assiniboine-Red (12) No No No No No No
Lower Saskatchewan-Nelson (14) No No Yes No No No
Great Lakes (19) No No Yes No No NoFootnote [A]
St. Lawrence (21) No No Yes No No Yes
Maritime Coastal (24) No No YesFootnote [A] No No No
Newfoundland-Labrador (25) No No No No No No
Data for this table
Detailed data for Table 2: Comparison between PBDE subgroup concentrations in sediment against the guidelines, 2009 to 2014
Sampling period Sampled drainage region Sample size triBDEFootnote [A] tetraBDEFootnote [A] pentaBDEFootnote [A] hexaBDEFootnote [A] octaBDEFootnote [A] decaBDEFootnote [A]
2009-2014 Pacific Coastal (1) 5 0 0 3 0 0 1
2009-2014 Okanagan-Similkameen (3) 2 0 0 1 0 0 0
2009-2014 Columbia (4) 1 0 0 0 0 0 0
2009-2014 Assiniboine-Red (12) 1 0 0 0 0 0 0
2009-2014 Lower Saskatchewan-Nelson (14) 3 0 0 2 0 0 0
2009-2014 Great Lakes (19) 7 0 0 3 0 0 0
2009-2014 St. Lawrence (21) 67 0 0 23 0 0 14
2009-2014 Maritime Coastal (24) 10 0 0 4 0 0 0
2009-2014 Newfoundland-Labrador (25) 3 0 0 0 0 0 0
2007-2011 Pacific Coastal (1) 5 0 0 2 0 0 1
2007-2011 Okanagan-Similkameen (3) 2 0 0 0 0 0 0
2007-2011 Columbia (4) 2 0 0 0 0 0 0
2007-2011 Yukon (5) 1 0 0 0 0 0 0
2007-2011 Assiniboine-Red (12) 2 0 0 0 0 0 0
2007-2011 Lower Saskatchewan-Nelson (14) 3 0 0 2 0 0 0
2007-2011 Great Lakes (19) 34 0 0 14 0 0 11
2007-2011 St. Lawrence (21) 78 0 0 13 0 0 14
2007-2011 Maritime Coastal (24) 6 0 0 0 0 0 0
2007-2011 Newfoundland-Labrador (25) 2 0 0 0 0 0 0

Download data file (Excel/CSV; 1.54 KB)

Note: Ninety-nine surface sediment samples were collected in nine drainage regions between the years 2009-2010 and 2013-2014. "No" means no sample collected in the drainage region returned a concentration reading above the guideline. "Yes" means at least one sample collected in the drainage region returned a concentration reading above the guideline. Data from previous reporting measurements (2007-2011) for this indicator are also reported in the data table.
Source: Environment Canada (2014) Chemicals Management Plan Environmental Monitoring and Surveillance Program.

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