ASTHMA OR ALLERGIES? Asthma is a chronic disease affecting the airways that carry air in and out of the lungs. The inside walls of the airways become inflamed (swollen) and narrower so less air can flow through the lung tissues. This in turn causes wheezing, coughing, tightness in the chest, and trouble breathing. Asthma is linked to allergies, although not everyone with asthma has allergies. People with allergies tend to react more strongly to the presence of allergens such as animal dander, dust mites, pollen or mold, as well as cigarette smoke and air pollution.
SMOG MAKES BREATHING DIFFICULT: Pollution is one possible asthma trigger. Smog can make breathing difficult and can make human beings more susceptible to cardio-respiratory diseases. People already suffering from heart or lung disease are particularly affected. The two main ingredients in smog that affect human health are ground-level ozone and fine airborne particles.
WHAT IS SMOG? Smog is a mixture of air pollutants that form smoke and fog in the air. It is generally formed when ground level ozone, fine particles and other chemicals react on hot days. Ozone in the upper atmosphere protects the Earth from the sun's harmful ultraviolet rays, but at ground-level ozone is a highly irritating gas. It forms when two primary pollutants -- nitrogen oxides and volatile organic compounds -- react in sunlight and stagnant air. Most nitrogen oxides come from burning fossil fuels, while VOCs are gases that contain carbon, usually emitted by gasoline fumes and solvents, such as those found in some paints. Airborne particles, sometimes called aerosols, are microscopic particles of pollutants that can remain suspended in the air for a considerable length of time. Primary particles include windblown dust and soil, sea spray, pollen, and plant spores.
The American Industrial Hygiene Association contributed to the information contained in the TV portion of this report.