Air Quality: Measures and Data
Why is outdoor air quality a concern?The EPA has set National Ambient Air Quality Standards for six criteria pollutants (carbon monoxide, lead, nitrogen dioxide, sulfur dioxide, ozone and particulate matter). In Washington, particulate matter and ozone are the greatest concern and are monitored more closely. All particles found in the air — such as dust, dirt, soot, smoke, and liquid droplets — are particulate matter (PM). PM is often classified by the fineness of the particles: for example, PM2.5 consists of particles less than 2.5 micrometers in diameter. Most PM2.5 found in Washington’s air comes from
fires, dust, wood stoves, fire places, outdoor burning, vehicles, or factories.
Exposure to PM, especially PM2.5 has been linked to causing or worsening lung (including asthma) and cardiovascular disease (heart disease and stroke). People with these diseases, adults age 65 and older, and infants and children are more likely to be affected by breathing PM 2.5, especially as levels rise.
Studies have also shown that ozone can cause acute respiratory problems, worsen asthma, cause inflammation of lung tissue, and temporarily decrease lung capacity of healthy adults. Repeated exposure may scar lung tissue. The same groups of people that are sensitive to PM2.5 are sensitive to ozone. Ozone is an outdoor pollutant. When people are active they breathe more deeply and more often, which increases the amount of ozone or PM2.5 they breathe in.
How is air quality tracked?Washington has more than 70 ambient air monitoring stations that are part of a network of thousands of stations across the country that measure concentrations PM2.5 or ozone in the air. Washington’s monitors are placed in areas likely to have higher concentrations of air pollutants. High concentrations often occur in more urban regions where many people live. The number and location of air monitors changes periodically. The Washington State Department of Ecology displays air monitoring sites and type of pollutant monitored throughout Washington.
Monitors provide data for assessing whether areas are in attainment of the National Ambient Air Quality Standards and for assessing public health consequences of these pollutants in specific regions. Data from EPA, state, local, and tribal air pollution control agencies feed a national database, the Air Quality System (AQS). EPA uses the quality assured data for various assessment, modeling, and regulatory functions.
What can be done about air contaminants to minimize public health risk?Vulnerable or sensitive populations, such as older adults, people with lung or heart disease, and parents with children should be encouraged to check the Washington Air Quality Advisory (WAQA) or the EPA’s Air Quality Index (AQI). Both the WAQA and the AQI are color coded tools that indexes pollution levels to potential health impacts. Many states and their local counterparts use the AQI to determine the extent to which projected air pollution levels will pose a risk to health. The WAQA, developed by the Washington State Department of Ecology, is an index similar to AQI but sets levels for PM2.5 that are more protective of health. The public can use either of these indices to plan daily activities. Information on local conditions or programs (such as burn bans, or wood stove change-out incentives) is also available online at one of seven clean air agencies.
In some areas, local media use air quality forecasts telling the public when levels of PM2.5 or ozone are expected to rise. These forecasts can be used to encourage health-protective behaviors, such as limiting strenuous or outdoor activity. Health agencies and organizations can encourage vulnerable populations to listen for forecasts or check air quality conditions online to encourage the public to minimize exposure to air pollution. Additionally, in many parts of Washington people can sign-up for email alerts on poor air quality conditions from the American Lung Association of Washington, “Action Network.”