Mercury is poisonous to which organs?

• A. Heart and lungs.
• B. Kidneys and the brain.
• C. Bones and muscles.
• D. Skin.

Answer: (B)

Mercury toxicity depends on its form, but the most notable targets are the kidneys and the brain. Inorganic mercury tends to accumulate in the kidneys, causing nephrotoxicity as it damages the organ’s filtering tissues. Organic mercury, such as methylmercury, crosses the blood‑brain barrier and accumulates in the brain, leading to neurotoxicity that can affect mood, coordination, and cognitive function. While mercury can affect other organs in certain exposure scenarios (for example, inhaled mercury vapor can impact the lungs), the two organs most consistently and severely impacted across common exposure scenarios are the kidneys and the brain. That’s why the correct understanding is that mercury is poisonous to the kidneys and the brain.