Which is a chemical environmental hazard?

• A. Parasitic Worm
• B. Influenza
• C. Mercury
• D. Formaldehyde

Answer: (D)

Chemical environmental hazards are substances in the environment that cause harm due to their chemical properties, not because they’re living organisms. Formed widely in indoor environments, formaldehyde is a chemical that off-gasses from building materials, adhesives, pressed wood products, and certain textiles. Because it is a volatile organic compound, it can accumulate in indoor air and be inhaled, leading to irritation of the eyes, nose, and throat, coughing, and other respiratory symptoms. Long-term exposure has been linked to an increased cancer risk, making it a well-established chemical hazard in environmental health.

Parasitic worms and influenza are biological hazards—they’re living organisms or infectious agents rather than chemical substances. Mercury is also a chemical hazard, but the item highlights formaldehyde as a classic example of a widespread indoor chemical pollutant.