Regulatory Grade Monitors
Commercial Grade Monitors
Air Monitoring
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.
Current News
The Air Quality Index (AQI) Basics & Beyond
The physical environment is an important part of any person’s health and well-being. Understanding the quality of the air outside is the first step to avoiding exposure to harmful air pollution. This webpage describes the Air Quality Index (AQI), explain its six...
Regulatory Grade Monitors
Gravimetric Sampler:
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.
Beta-Attenuation Sampler:
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.
Nephelometer:
This monitoring equipment determines concentrations of particles by measuring the light reflected from particles in the air. This form of monitoring provides near-constant air quality information but has an initial high cost and requires continued maintenance and calibration.
Commercial Grade Monitors
Other forms of monitoring exist which are commercially available to purchase and install. These commercial grade sensors are significantly more affordable than their regulatory grade counterparts, but not sensitive or precise enough for regulatory reporting. However, many of these monitors are accurate enough to provide useful air quality information for general purposes. LRAPA has installed a network of over 90 commercial grade particulate matter sensors called, “Purple Air Sensors” throughout lane county.
Purple Air Sensor:
These sensors provide real-time Particulate Matter measurements. The sensor determines concentrations of particles by measuring the light reflected from particles in the air. Data is uploaded to the internet via wireless internet connection.
A Guide to Purple Air Sensors | Una guía para los sensores de Purple Air
To access the purple air sensors in Lane County, visit the EPA’s Fire and Smoke Map. Or download the AirNow app from the Apple App Store, or the Google Play Store.
For more information about LRAPA’s Purple Air correction factor, read the staff report on the development of the correction factor.