Measurement of air pollutants

The measurement of atmospheric pollutants allows to determine their impacts on human and animal health, vegetation, materials, and the wider environment to be determined. It also provides the data to monitor compliance with regulatory controls, and to advise the general public of current air quality levels and pollution warnings as appropriate. This article describes the framework within which air pollutants are monitored and the units used for their quantification, and then introduces the commonly monitored atmospheric pollutants, focusing on boundary layer air quality: ozone, oxides of nitrogen, carbon monoxide, sulfur dioxide, lead, volatile organic compounds, and particulate matter. The principal techniques used to detect each species, with an emphasis on the physicochemical principles employed, and an indication of the measurement performance achieved and potential shortcomings of each method are described. Finally, the article summarizes the approach to monitoring long-lived pollutants such as greenhouse gases and ozone-depleting agents.