Children and the elderly may also be sensitive. In persons with asthma, the clinical symptoms of brief exposure to low concentrations of sulfur dioxide are shortness of breath, wheezing, and coughing. People chronically exposed to sulfur dioxide have a higher incidence of persistent cough, shortness of breath, bronchitis, fatigue, and colds of long duration. Research suggests that the current federal standard for sulfur dioxide may not be protective enough of human health. Other effects of sulfur dioxide Sulfur dioxide is one of the ingredients of acid rain.
Acid rain changes the chemistry of lakes and streams, which destroys aquatic life.
It makes soil more acid, damages building materials, cloth, and metals, and can potentially contaminate drinking water. Sulfur dioxide can also cause a whitish haze resulting in decreased visibility, and can damage trees and agricultural crops. Some of these effects apparently occur at levels below the federal standard. The Washington Clean Air Act adopted in 1991 includes measures for reducing the amount of sulfur dioxide in the air. These include a permit program for industrial facilities and reductions in traffic and the use of single-occupant vehicles.