Human and Wildlife Toxicological Concerns

Much of our current understanding of these impacts arose from research on wildlife and human populations within the Great Lakes basin. Despite being banned in North America more than 25 years ago, the toxicological risks from PCB exposure are still a present-day concern. For example, current PCB concentrations in fish in the Great Lakes are sufficiently large as to drive the need for fish consumption advisories for sport fish and to restrict commercial fisheries. 

Humans, fish, and wildlife are exposed to PCBs from a number of different exposure routes, including respiration, water consumption, food consumption, and dermal contact with contaminated water, soil, etc. However, the dominant exposure route is food consumption, and especially the consumption of fish. This is because PCBs bioaccumulate effectively in fats and lipids [35]. As a result, most PCB congeners (including the most toxic ones) biomagnify in the food web, which means that the higher levels of the food web will have greater concentrations than lower ones (see full discussion in the section on food web dynamics). As a result, adverse effects have been observed in fish-eating animals and birds, and in humans that have consumed fish (occupationally exposed workers are not considered in this discussion). 

The literature on PCB toxicological effects is vast, and only those studies that relate more directly to the Great Lakes will be discussed here. There have been numerous workshop publications as well as reviews on this topic over time [3,4,36-48]. 

---