Which of the following toxins affects the kidneys?

• A. Carbon monoxide
• B. Benzene
• C. Mercury
• D. Alcohol

Answer: (C)

The correct answer is mercury, which is a known nephrotoxin that can have detrimental effects on the kidneys. When mercury enters the body, it can accumulate in kidney tissue, leading to acute kidney injury and potentially chronic kidney disease with prolonged exposure. Mercury disrupts normal cellular function and can cause inflammation and cell death, directly impairing the kidneys' ability to filter waste from the blood.

Other substances listed, while harmful, affect different organs or systems in the body. Carbon monoxide, for example, primarily impacts the cardiovascular system and can lead to hypoxia. Benzene is known for its effects on the bone marrow and can lead to blood disorders. Alcohol primarily affects the liver and can lead to a range of liver-related issues, such as fatty liver disease and cirrhosis, rather than directly causing kidney damage.