Which option correctly distinguishes heavy metals from organic persistent pollutants and provides examples of each?

• A. Heavy metals such as lead and mercury; organic persistent pollutants such as PCBs and DDT.
• B. Heavy metals such as PCBs and DDT; organic persistent pollutants such as lead and mercury.
• C. Heavy metals such as arsenic and chromium; organic persistent pollutants such as nitrates and phosphates.
• D. Heavy metals such as pesticides; organic persistent pollutants such as metals.

Answer: (A)

The distinction hinges on inorganic elements versus organic compounds that resist degradation. Heavy metals are inorganic metallic elements that persist in the environment and organisms, often accumulating in tissues and causing toxicity; lead and mercury are classic examples. Organic persistent pollutants are carbon-based compounds that are chemically stable and lipophilic, so they persist in air, water, and living tissues and tend to bioaccumulate; PCBs and DDT are well-known examples. This pairing correctly shows metals as examples of heavy metals and PCBs with DDT as persistent organic pollutants. The other candidates mix categories—PCBs and DDT aren’t metals, nitrates and phosphates are nutrients rather than organic pollutants, and pesticides aren’t metals.