Why is arsenic dangerous?

• A. Inert in the environment
• B. Essential nutrient
• C. Not toxic under any circumstances
• D. Highly toxic and carcinogenic

Answer: (D)

Arsenic is dangerous because it is highly toxic and carcinogenic. It readily interacts with biological systems and disrupts essential cellular processes, rather than being harmless or inert. Inorganic forms of arsenic, especially arsenite and arsenate, interfere with how cells generate energy by inhibiting key enzymes and mitochondrial function, while also producing oxidative stress and damaging DNA. These effects accumulate over time with chronic exposure, leading to serious health problems such as skin lesions and multiple cancers (notably skin, lung, and bladder), as well as cardiovascular and neurological issues. Because of the strong and well-documented cancer risk, arsenic is classified as a known human carcinogen. It is not inert in the environment, it is not an essential nutrient for humans, and it is not non-toxic under any circumstances; exposure can harm health even at low levels, with greater harm at higher exposures.