API 26-60045-1978 EFFECTS OF OXIDES OF NITROGEN@ CARBON MONOXIDE AND PHOTOCHEMICAL OXIDANTS ON THE ECG DURING EXERCISE AND ON CARDIOPULMONARY FUNCTION - FINAL REPORT
INTRODUCTION The purpose of this project is to assess short-term health effects of community air pollutants largely attributable to automotive sources. The long-term goal is to help provide an adequate data base for the setting of rational ambient air quality standards. Previous studies of the more common pollutant gases here and elsewhere have implicated ozone (03) as the pollutant most likely to produce harmful effects at concentrations attainable in ambient pollution episodes. Respiratory symptoms and disturbances of pulmonary function test performance have been found at concentrations as low as 0.37 ppm (neutral buffered potassium iodide method) in two-hour exposures realistically simulating ambient exposure conditions. (1) Possible slight effects have been found in very small groups of subjects at 0.25 ppm@ with light intermittent exercise@ (2) or at 0.15 ppm with mouth breathing and heavy exercise. (3) However@ in a group of 22 asthmatics@ expected to be at high risk of adverse effect@ no respiratory symptoms or changes in lung function test results were found after two-hour exposure to 0.2 ppm with light intermittent exercise. (4) These results@ on the whole@ suggest that the National Ambient Air Quality Standard (NAAQS) for ozone (0.08 ppm for one hour@ not to be exceeded more than once a year) probably provides a substantial margin below a short-term detectable-adverse-effect level. An ozone (or oxidant) air-quality standard must be concerned not only with the effects of ozone alone@ but also with its effects in mixtures of other potentially toxic substances such as occur in actual pollution episodes. One study (5) showed an apparent marked synergism of 03 and sulfur dioxide (S02)' both at 0.37 ppm@ in producing respiratory function changes. A follow-up study in our laboratory (.6) showed much less evidence of synergism@ but also showed that particulate sulfate formed to a slight extent from mixed 03 and S02 even in highly purified background air@ and to a much greater extent in less pure air. Thus it appeared that particulate sulfate might well be an important contributor to toxicity of 03-containing mixtures@ and might explain the relatively severe responses first attributed to 03 plus S02'
API 26-60045-1978 history
1978API 26-60045-1978 EFFECTS OF OXIDES OF NITROGEN@ CARBON MONOXIDE AND PHOTOCHEMICAL OXIDANTS ON THE ECG DURING EXERCISE AND ON CARDIOPULMONARY FUNCTION - FINAL REPORT