How does mercury contaminate seafood?
Methylmercury is a byproduct of mercury, which can occur in nature but is more commonly released into the air through industrial pollution. When mercury falls from the air into oceans, streams and rivers, bacteria in the water transform the compound into methylmercury, a known toxin. As fish live and feed in these waters, they absorb the methylmercury; as bigger fish feed on smaller fish, they absorb increasing amounts of the compound. As a result of this process, all seafood contains some amount of methylmercury. “The higher up the food chain you go, the more methylmercury you get,” explains Gary J. Myers, M.D., a professor of neurology, pediatrics and environmental health at the University of Rochester Medical Center in Rochester, N.Y. “It’s a simple matter of bio-accumulation: big fish eating little fish.” Almost all natural exposures to methylmercury are from exposure to seafood, Myers adds; most true mercury poisonings are due to environmental contamination (See question below for
