The phrase "gaseous pollutants" refers to harmful substances that exist in the form of gases in the air. These pollutants can be released from various sources and cause negative effects on the environment and human health. Full definition
Harmful gaseous pollutants in the form of volatile organic compounds are often released into the air when chemicals are used, for example in cleaning products. (sciencedaily.com)
These particles are emitted directly from natural sources or human activity, or they form from precursors emitted originally as gaseous pollutants. (sciencedaily.com)
The São Paulo State Environmental Corporation (CETESB), for example, routinely monitors only solid particles with diameters of 10,000 nm (PM10) and 2,500 nm (PM2.5)-- as well as other gaseous pollutants such as ozone (O3), carbon monoxide (CO) and nitrogen dioxide (NO2). (sciencedaily.com)