Regulatory Grade Monitors
Commercial Grade Monitors
Criteria Air Pollutants
The EPA sets national air quality standards (NAAQS) for six common pollutants, also called criteria pollutants, to protect public health. Monitoring sites across the United States report data to EPA for these six criteria air pollutants:
- Ozone (O3)
- Particulate matter (PM10 and PM2.5)
- Carbon monoxide (CO)
- Nitrogen dioxide (NO2)
- Sulfur dioxide (SO2)
- Lead (Pb)
(PM10 includes particles less than or equal to 10 micrometers in diameter. PM2.5 includes particles less than or equal to 2.5 micrometers and is also called fine particle pollution.)
LRAPA currently monitors for two of these criteria pollutants, Ozone and Particulate Matter. The other four criteria pollutants have been monitored for in the past and have shown that they do not meet levels of concern and continued monitoring.
Hazardous Air Pollutants (HAPs) / Toxic Air Pollutants
Hazardous air pollutants (HAPs) (also called toxic air pollutants or air toxics) are pollutants that are known or suspected to cause serious health problems such as cancer. There are 188 such hazardous air pollutants (HAPs) identified by the EPA. Examples of these toxic air pollutants include acetaldehyde, which can be emitted from wood stoves/fireplaces and gasoline powered engines; arsenic, which is naturally occurring in the Pacific Northwest due to volcanic origins but can also be found in agricultural pesticides and some metal processing activities; benzene, which is found in gasoline; formaldehyde which can be emitted by incomplete fuel combustion, railroad emissions, and wood burning; and naphthalene, which is can be released from the burning of diesel, or use of creosote. Examples of other pollutants listed as air toxics include dioxin, asbestos, and metals such as cadmium, mercury, chromium, and lead compounds. The National Air Toxics Assessment (NATA) is EPA’s ongoing comprehensive evaluation of air toxics in the U.S.
Regulatory Grade Monitors
This monitoring equipment pulls a known volume of ambient air through very fine filters that are weighed at a lab with an extremely sensitive scale called a micro-balance. This highly accurate form of measuring air is slow and requires significant staff time and effort which involves trips to retrieve filters then time to weigh and report the findings.
This monitoring equipment provides hourly data points by measuring the adsorbed beta radiation to determine air quality. This FEM monitoring equipment can be cumbersome to setup and requires continued maintenance and calibration.