Final answer:
A bone in a fish fillet is a physical contaminant. However, fish can also contain chemical contaminants like polychlorinated biphenyls (PCBs) and heavy metals, which can accumulate in their bodies through a process known as biomagnification.
Step-by-step explanation:
A bone in a fish fillet is an example of a physical contaminant in food. However, there are also chemical contaminants that can be present in fish, such as polychlorinated biphenyls (PCBs) and heavy metals like mercury, lead, and cadmium. These substances can accumulate in the bodies of fish, a process known as biomagnification.
The bodies of water where fish live often contain very low concentrations of these toxic substances, but predatory fish can accumulate high concentrations from consuming other organisms that have absorbed these toxins. For example, a study by the National Oceanic and Atmospheric Administration (NOAA) in the Saginaw Bay of Lake Huron in the North American Great Lakes found that the amount of PCBs in the walleye species of fish was more than four times higher than that in phytoplankton at the base of the food chain.
Biomagnification also means that birds eating these fish can have much higher levels of PCBs than the fish themselves. Similarly, certain types of seafood, like swordfish, shark, king mackerel, and tilefish, are known to have high mercury content due to biomagnification. For this reason, the United States Environmental Protection Agency (EPA) recommends that pregnant women and young children avoid these types of seafood.
Learn more about Biomagnification