Outdoor Air Quality
To protect human health and the environment, the Clean Air Act amendments of 1990 established standards for six air pollutants. Two of those air pollutants, ozone and particulate matter, can reach unhealthy concentrations in the Washington Metropolitan Region.
Current Regional Air Quality
What is an Air Quality Action Day?
Air Quality Action Days occur when air pollution in the region is expected to reach unhealthy levels. They occur primarily during the summer months when hot, humid, and stagnant weather conditions contribute to the formation of air pollution.
Health Concerns on Air Quality Action Days
Ground-level ozone is an air pollutant that damages human health, vegetation, and is a key ingredient of urban smog. Repeated exposure may cause permanent damage to the lungs and trigger a variety of health problems including chest pains, coughing, nausea, throat irritation, and congestion. Exposure can also worsen bronchitis, heart disease, emphysema, and asthma, and reduce lung capacity.
What is the Air Quality Index?
The Air Quality Index (AQI) is EPA's tool for communicating air quality to the public. The AQI uses both a color-coded and numerical scale to report how clean or polluted the air is and what associated health effects might be of concern. The higher the AQI value, the greater the level of air pollution and the greater the health concern.
What is an Air Quality Action Days Participant?
Air Quality Action Days participants are public and private individuals and organizations that have agreed to develop voluntary Air Quality Action Day plans. These plans range from notifying employees and customers of an Air Quality Action Day to rescheduling emission producing operational activities that contribute to the Region's poor air quality, such as lawn mowing and pesticide application. Air Quality Action Days empower government agencies, businesses, and residents to do their share for cleaner air. During Air Quality Action Days, all sectors of the community will be called on to take voluntary actions to reduce air pollution.
How are Air Quality Action Days Announced?
A team of meteorologists and scientists produce air quality forecasts for the Washington Metropolitan area for the following day, usually by 3:00 pm. The Metropolitan Washington Area Council of Governments (MWCOG) receives the forecast and notifies Air Quality Action Day participants, other organizations, the news media, and the public in the event of a Code Orange/Red forecast. Current air quality forecasts are announced by Clean Air Partners.
For more information, read the Clean Air Partners Air Quality Action Guide (PDF, 653KB)