Which statement best describes mercury pollution as described?

• A. Mercury can enter water, become methylmercury, build up in fish, and harm the nervous system.
• B. Mercury is harmless to all organisms.
• C. Mercury only affects the air.
• D. Mercury has no health impacts.

Answer: (A)

Mercury pollution follows a pathway where mercury released into the environment can enter waterways, where certain microbes convert inorganic mercury into methylmercury, a highly toxic form. This methylmercury readily bioaccumulates in aquatic organisms and becomes more concentrated up the food chain, so fish can harbor high levels. When people consume contaminated fish, mercury acts as a neurotoxin, harming the nervous system, especially in developing fetuses and young children. This combination of transformation, accumulation in fish, and neurotoxic health effects is why that description best captures how mercury pollution operates.