The biological effects of photochemical air pollutants on man and animals.

Abstract

Common manifestations of atmospheric photochemical smog are eye irritation, respiratory distress, haze formation (reduction in visibility), peculiar odors, characteristic vegetation damage, and excessive cracking of rubber products as well as the presence of unusually high levels of oxidizing substances identified as photochemical oxidants. They can be measured routinely in community atmospheres and analyzed collectively for total oxidant, the net oxidizing effect of all such substances in the atmosphere, thus serving as useful indices of effective levels of photochemical pollution. Ozone and perocyacyl nitrates (PAN compounds) have been identified as important oxidants found in photochemical smog. Data based on laboratory exposures of man and animals to ozone and PAN compounds are reviewed. The photochemical oxidants, particularly ozone, are severe respiratory irritants which cause temporarily impaired lung function in man and animals in short exposures. In prolonged exposures, there is an increase in mortality of newborn animals as well as of animals exposed to respiratory infection. Recent studies indicate a decreased birth rate of laboratory animals in prolonged exposures to synthetic photochemical smog. Additionally, late studies have shown that an increase in lung tumor formation occurred in aging mice exposed to atmospheric photochemical smog over a 16-month study period when compared tomore » controls exposed to filtered air. 79 references.« less