How do you detect the air pollution?

Air is monitored by:

* Processing a lot of air though a filter or absorption systems and then seeing what was caught. this works for gaseous pollutants (SOx, NOx, hydrocarbons) and particulates. * Exposing reactive chemicals to ambient air for extended periods of time to see what was in the ambient air. (Sulfur candles)

* Passing light (lasers) through the air and recording the wavelengths that were absorbed or reflected from the air pollutants. * Monitoring the percent of light obstructed by the pollutant in the air (opacity) * Organoleptic monitoring (a fancy way of saying you sniff and look at the air with your senses) * Examining the impact of the air pollutant on plants (Phytotoxicological examonation) either in labs or in the field (Pollutants such as SOx and ethylene) * Monitoring epidemiological studies to determine long term impacts on human health