Sulfur dioxide (SO2)

Sulfur dioxide (SO2), a colorless, reactive gas, is produced during the burning of sulfur-containing fuels such as coal and oil, during metal smelting, and by other industrial processes. Major sources include power plants and industrial boilers. Generally, the highest concentrations of sulfur dioxide are found near large industrial sources.

Health Effects

Children and adults with asthma who are active outdoors are most vulnerable to the health effects of sulfur dioxide. The primary effect they experience, even with brief exposure, is a narrowing of the airways (called bronchoconstriction), which may cause symptoms such as wheezing, chest tightness, and shortness of breath. Symptoms increase as sulfur dioxide concentrations and/or breathing rates increase. When exposure ceases, lung function typically returns to normal within an hour.

At very high levels, sulfur dioxide may cause wheezing, chest tightness, and shortness of breath in people who do not have asthma.

Long-term exposure to both sulfur dioxide and fine particles (PM) can cause respiratory illness, alter the lung's defense mechanisms, and aggravate existing cardiovascular disease. People who may be most susceptible to these effects include individuals with cardiovascular disease or chronic lung disease, as well as children and the elderly.

If you have any questions please contact your health care provider.