Measures the quality of all the air in a particular place. Almost all the evidence of health effects is based on these measurements. Ambient air quality criteria, or standards, are concentrations of pollutants in the air, and typically refer to outdoor air. The criteria are specified for a variety of reasons including for the protection of human health, buildings, crops, vegetation, ecosystems, as well as for planning and other purposes. CERL provides its services in measuring the concentration of the pollutants in the air according to the SEPA.Standards and guidelines.