Which indoor air pollutants are classified as particulates?

Which indoor air pollutants are classified as particulates?

• A. asbestos, dust, smoke
• B. carbon monoxide and ozone
• C. carbon dioxide
• D. nitrogen oxides

Answer: (A)

Particulates are solid or liquid particles suspended in the air. Indoors, asbestos fibers, dust, and smoke fit that definition because each consists of tiny particles that can float in the air and be inhaled. Asbestos fibers can be released from old insulation or building materials when disturbed, dust is a mix of tiny mineral and organic particles that accumulate from everyday activities, and smoke contains fine solid and liquid particles produced by burning. The other options are gases, not particulates. Carbon monoxide and ozone are gaseous pollutants formed from chemical reactions or combustion; carbon dioxide is a gas, and nitrogen oxides are also gases. Since they do not exist as suspended solid or liquid particles, they aren’t classified as particulates.

Particulates are solid or liquid particles suspended in the air. Indoors, asbestos fibers, dust, and smoke fit that definition because each consists of tiny particles that can float in the air and be inhaled. Asbestos fibers can be released from old insulation or building materials when disturbed, dust is a mix of tiny mineral and organic particles that accumulate from everyday activities, and smoke contains fine solid and liquid particles produced by burning.

The other options are gases, not particulates. Carbon monoxide and ozone are gaseous pollutants formed from chemical reactions or combustion; carbon dioxide is a gas, and nitrogen oxides are also gases. Since they do not exist as suspended solid or liquid particles, they aren’t classified as particulates.