Outdoor Air Quality

Outdoor air - the air outside buildings, from ground level to several miles above the Earth's surface - is a valuable resource for current and future generations because it provides essential gases to sustain life and it shields the Earth from harmful radiation. Poor outdoor air quality can affect your health and can worsen the symptoms of bronchitis, emphysema, and asthma. The Clean Air Act requires the Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for six common air pollutants. These include gound-level ozone, particulate matter, carbon monoxide, lead, sulfur dioxide, and nitrogen dioxide.The Rhode Island Department of Environmental Management (RIDEM) regulates air pollutants in Rhode Island. data

Six Common Outdoor Air Pollutants

Ground-Level Ozone

Ozone at ground level is an air pollutant and is the main ingredient in smog. Ozone can harm your health and can trigger chest pain, coughing, throat irritation, and can harm your lungs. People most at risk from breathing air with ozone include people with asthma, people who are active outdoors, children, and older adults. Ozone can also affect sensitive vegetation because it is more likely to occur in high concentrations during the growing season.

Fine Particulate Matter

Fine particulate matter are very small particles, generally less than 2.5 micrometers in size that can be inhaled into the lungs and can pass into the bloodstream. These can be either microscopic solid particles, like those in smoke, or liquid droplets formed in the atmosphere from many different chemicals. Fine particles are the main cause of haze in parts of the United States.

Carbon Monoxide

Carbon Monoxide is a colorless, odorless gas that can be harmful. Carbon monoxide can build up inside buildings but can also cause problems outdoors. The largest outdoor sources are cars, trucks, and other machinery that burn fossil fuels. High outdoor levels of carbon monoxide can be dangerous for those with heart disease.


Lead is regulated by the EPA because it can occur at high levels near metals processing, waste incinerators, or certain manufacturing. Levels of lead in the air decreased by 98 percent between 1980 and 2014 due to the removal of lead from gasoline for motor vehicles.

Sulfur Dioxide

Short-term exposure to sulfur dioxide can cause harm to the respiratory system and make breathing difficult for sensitive people such as children and those with asthma. Sulfur oxides can combine with other chemicals to create fine particles. The largest source of sulfur oxides is the burning of fossil fuels.

Nitrogen Dioxide

Nitrogen oxides also form from burning of fossil fuels. They can combine with oxygen and other chemicals to form acid rain, and they contribute to haze. People with asthma, children, and the elderly are most at risk from breathing nitrogen dioxide. Breathing these pollutants can worsen respiratory diseases and can lead to asthma attacks and respiratory infections.

Ways You Can Help Improve Outdoor Air Quality

  • Whenever possible: walk, bike, skate, bus or car pool instead of driving your vehicle.
  • Purchase fuel-efficient vehicles.
  • Practice energy conservation at home and work.
  • Use Green Building techniques when building and remodeling your home or business to conserve energy and reduce exposure to toxic chemicals.
  • Install solar energy on your home or business.