PCBs have toxic effects on the immune, reproductive, nervous, and hormonal systems of humans and other living things. PCBs accumulate in living things, which are amplified when predators eat their prey known as biomagnification. Biomagnification is the entry of chemicals from the environment through the food chain which eventually levels of chemical concentrations in organisms are very high and higher than bioaccumulation. Can be seen from Figure 1.

As seen in Figure 1. PCBs are released from a variety of sources such as urban industrial waste, agriculture, and stormwater runoff can all introduce harmful substances into water. Rain can also carry chemicals from the soil or air into rivers and lakes. Fish absorb contaminants such as PCBs from the water, sediment, and food they eat. In contaminated areas, bottom-dwelling fish are most likely to have high levels of these chemicals because they settle to the bottom where they feed. Phytoplankton then absorb PCBs and zooplankton eat phytoplankton. Then herring eat zooplankton and salmon eat herring. Finally large mammals such as orca whales eat salmon.

Fish contaminated with PCBs can build up in the body over time and can cause health problems. It can take 5 years or more for women of childbearing age to clear their bodies of PCBs. PCBs have been linked to developmental problems in children whose mothers were exposed to PCBs before pregnancy. PCBs can cause changes in human blood, liver, and immune function in adults.

References
- https://ecology.wa.gov/blog/august-2014/tackling-toxics-pcb-problem-requires-creative-solu. Accessed on October 9, 2024. 10:15 WIB.
- https://doh.wa.gov/community-and-environment/food/fish/contaminants-fish. Accessed on October 9, 2024. 10:15 WIB