A pollutant of emerging concern (PEC) is best described as what?

• A. A chemical not yet fully regulated but potentially harmful to health or environment.
• B. A chemical that is fully regulated and proven safe.
• C. A substance that is always present in drinking water.
• D. A pollutant that never persists in the environment.

Answer: (A)

A pollutant of emerging concern is a chemical not yet fully regulated but potentially harmful to health or the environment. This category covers substances detected or suspected to cause adverse effects based on new research or monitoring, for which regulators may still be collecting hazard and exposure data and have not established binding standards. It’s not about being proven safe or always present in water; and it doesn’t require that the substance never persists—persistence can vary among PECs. Examples include emerging contaminants like certain pharmaceuticals, personal care product residues, some PFAS, and microplastics that are gaining attention as they are detected and studied, even though formal regulation may still be developing.