It also is associated with increased emergency room visits, asthma attacks, decreased lung function and other respiratory problems. Those most at risk include the elderly, people with cardiopulmonary disease such as asthma, and children. Particulate soot is a major cause of reduced visibility in many parts of the United States. It also can cause damage to paints and building materials.
Some particles are large enough to be visible as smoke or soot.
Others are so small they can be detected only with an electron microscope. Some particles are emitted directly from their sources, for example, smokestacks and cars. In other cases, gases such as sulfur oxides and nitrogen oxides interact with other compounds in the air to form fine particles. These tiny bits of soot can travel hundreds of miles downwind of the original pollution sources. All Rights Reserved.