Measuring PCBs, PCDDs, and PCDFs in Chinook Salmon of the Chemainus and Cowichan Rivers

Halalt and Cowichan First Nations (Vancouver Island, British Columbia) have relied on fish for generations as a major food source. Given the high consumption of chinook salmon from the Chemainus and Cowichan Rivers, community members were concerned about the potential for persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCB), polychlorinated dibenzodioxins (PCDD), and polychlorinated dibenzofurans (PCDF), to reach levels that are detrimental to human health.

This study team sampled chinook salmon from the Chemainus and Cowichan Rivers to measure the concentrations of PCB, PCDD, and PCDF contamination and to determine if this level of contamination posed any potential health risks to the Halalt and Cowichan communities. The study also estimated daily dietary PCB, PCDD, and PCDF intake from chinook salmon based on consumption data collected by the First Nations Food, Nutrition & Environment Study (FNFNES) in British Columbia (2008/09). The dietary intake of selected POPs was compared to Health Canada guidelines.

The study found that all chinook samples contained low concentrations of PCB, PCDD and PCDF. Therefore, at current consumption rates of chinook salmon from the Chemainus or Cowichan Rivers, exposure to these selected contaminants did not pose human health risks.  Considering the benefits of eating salmon and the low concentrations of PCB, PCDD, and PCDF in the locally harvested chinook salmon, the project team concluded there was no reason to issue any restrictions on consumption.