The World Health Organization reports that 3 million people now die each year from the effects of air pollution, three times the number of deaths each year in automobile accidents. A study published in The Lancet in 2000 concluded that air pollution in France, Austria, and Switzerland is responsible for more than 40,000 deaths annually in those three countries alone. About half of these deaths can be traced to air pollution from vehicle emissions.
In the United States, traffic fatalities total just over 40,000 per year, while air pollution claims 70,000 lives annually. U.S. air pollution deaths are equal to deaths from breast cancer and prostate cancer combined.
Air pollutants include carbon monoxide, ozone, sulfur dioxide, nitrogen oxides, and particulates. These pollutants come primarily from the combustion of fossil fuels, principally in coal-fired power plants and in gasoline-powered automobiles. Nitrogen oxides can lead to the formation of ground-level ozone, among other things helping to cause smog, which is primarily composed of ozone and particulates. Particulates are emitted from a variety of sources, primarily diesel engines.
The air in most urban areas typically contains a mixture of pollutants, each of which may increase a person's vulnerability to the effects of the others. Exposure to carbon monoxide slows reflexes and causes drowsiness because carbon monoxide molecules bind to hemoglobin, reducing the amount of oxygen that red blood cells can carry. Nitrogen dioxide can aggravate asthma and reduce lung function, as well as making airways more sensitive to allergens. Ozone also causes lung inflammation and reduces lung function and exercise capacity.
Smaller particulates, especially those 10 micrometers in diameter (1/2,400 of an inch) or smaller, can become lodged in the alveolar sacs of the lungs. They are associated with higher admissions to hospitals for respiratory problems and with increased mortality, particularly from respiratory and cardiovascular diseases. As particulate concentrations in the air rise, so do death rates.
When people inhale particulates and ozone in the concentrations commonly found in urban areas, their arteries become more constricted, thus reducing blood flow and oxygen supply to the heart. This is why air pollution aggravates heart conditions and asthma.
Unlike some pollutants that have threshold levels below which no health effects are seen, ozone and particulates have negative health effects even at very low levels. Thus, no safe level of such pollutants exists. Research published in Science in 2001 noted that in industrial as well as developing countries, exposures to current levels of ozone and particulates "affect death rates, hospitalizations and medical visits, complications of asthma and bronchitis, days of work lost, restricted-activity days, and a variety of measures of lung damage."
Increased monetary expenses related to air pollution-induced illness include the costs of medication, absences from work, and child care. In the Canadian province of Ontario, for example, which has a population of 11. …