Which variety of mercury is found in food?

• A. Methylmercury
• B. Ethylmercury
• C. Inorganic mercury
• D. Metallic mercury

Answer: (A)

Mercury in food is mainly methylmercury because it forms when bacteria in aquatic environments convert inorganic mercury into methylmercury, which then bioaccumulates in fish and concentrates up the food chain. This organic form is readily absorbed from the digestive tract and accumulates in muscle tissue of seafood, so people are exposed primarily through dietary fish and shellfish. Methylmercury also crosses the placenta and the blood–brain barrier, making it especially concerning for fetal and early-child development, and it tends to persist in the body for weeks to months because its elimination is relatively slow. Cooking does not reliably remove methylmercury, so exposure reflects intake from contaminated seafood rather than food processing.

Inorganic mercury and metallic mercury are not the forms typically found in foods in meaningful amounts, and ethylmercury is mainly associated with certain preservatives in products like vaccines, not with common dietary sources.