The survival of man depends on his ability to adapt himself to his environment. For thousands of years changes in man’s environment resulted from natural causes beyond his control; he tried to mitigate their impact by migrating from regions that had become unfavorable to regions more favorable. Such attempts were not always successful, for various types of primitive man disappeared. About one hundred years have passed since modern man first experimented in modifying his natural environment by the addition of numerous new and often artificial products created by modern industry. Occupational diseases furnish a vivid example of the many and frequently serious new health hazards to which the industrially employed part of mankind has become exposed. The inclusion of some of these agents in consumer goods, such as foodstuffs, cosmetics, medicines, household goods and clothing, and their sometimes indiscriminate use have brought the general population into close contact with the injurious factors in the modern industrial environment. Perhaps the most important and alarming aspect of the recent change in human environment is the increasing and often severe pollution of the air, soil and water with both industrial wastes and regular products of industrial manufacture, such as pesticides and coal and petroleum road tars and asphalts, injurious to human health. The recent disaster at Donora called attention to the problem of air pollution by industrial gases and fumes containing sulfur dioxide, arsenic and fluorine, originating from smelters.
