AIR AND HEALTH
There is accumulating evidence that air pollution is producing harmful effects
in man. Many studies plus common sense reveal that air pollution may cause reduced
visibility, eye irritation, and respiratory irritation. Some medical studies link air
pollution with lung cancer, emphysema and other diseases.
In London, for example, respiratory diseases including chronic bronchitis and
emphysema which can cause heart failure, are the third cause of death in men over 45
years of age. Many British doctors attribute the rapid increase in chronic respiratory
disease rates to polluted air. The death-rate from emphysema among Californians has
quadrupled in the last 10 years,
The severity of symptoms of illness increases proportionately with
concentration of pollutants in the air. The first effects of air pollutants are likely to
lead to discomfort. Though not known to be associated with the development of
disease, even in sensitive groups, these efforts are capable of disturbing the comfort
of the population in residential or industrial areas. This level is the one at which eye
irritation occurs. Also in this category are levels of pollutants that damage vegetation
and reduce visibility. A more serious level of pollutants, or possibly combination of
pollutants, is likely to lead to insidious or chronic diseases or to significant alteration
of important physiological function in a "sensitive group" such as the aged or
sufferers from chronic respiratory or heart disease. Pollution would not necessarily be
a risk for persons in good health. But under conditions of intense pollution, this
"sensitive group" may die.
Three episodes of acute air pollution have been characterized by sudden death.
These tragedies occurred in Belgium's Meuse Valley in 1930, in Donora,
Pennsylvania, in 1947, and in London in 1952. In each case a heavy fog settled over
the area and did not lift; in each case the phenomenon was produced by a temperature
inversion or a layer of warm air over a layer of cold air, and in each case there was a
heavy concentration of smoke and pollutants.
During these periods, 63 deaths in Meuse Valley, 20 deaths in Donora, and
3.000 deaths in London were attributed to air pollution. Most of those who died were
elderly people already suffering from diseases of the respiratory or circulatory
systems. This disaster in London was a major factor in hastening the Clean Air Act of
1956. The omission of dark smoke from industrial chimneys was prohibited for the
whole country.
Three general types of substances are known to pollute the atmospheres of all
industrial environments: chemical, radioactive and biological. Chemical pollutants
are the major concern because of expanding industrial, automobile and domestic
wastes. However, radioactive pollutants add to the total radiation exposure in both
urban and rural air. Biological dusts and pollens likewise may cause effects,
especially in persons who react to them with hay fever, asthma, and other allergies.
