Research Program Area: Health & Exposure
Topic Areas: Health Effects of Air Pollution
This study was designed to evaluate the interactions of carbon monoxide (50 ppm), peroxyacetylnitrate (0.27 ppm), and temperature stress on man's maximal working capacity and his ability to work at one-third capacity for four hours. Other factors evaluated were the effects of age and smoking habits. There were no consistent pollutant effects on attained maximal capacity, although carbon monoxide exposures were effective in reducing the work time of both younger nonsmokers and older subjects. Decrements of maximal aerobic power were related to age, heat, and length of time of smoking. With higher levels of ambient carbon monoxide (75 ppm and 100 ppm), reduction of maximal power occurred at 100 ppm - blood carboxyhemoglobin level of 5.0%. When initial levels of carboxyhemoglobin were elevated to the same degree, an ambient carbon monoxide concentration of 16-20 ppm was capable of maintaining the blood carboxyhemoglobin levels regardless of the level of pulmonary ventilation. Following four-hour exposures, reduction in forced vital capacity of the younger subjects occurred only when peroxyacetylnitrate was present. Generally, the pollutant exposures produced no significant changes in the cardiovascular, temperature regulatory, or metabolic responses to exercise. Older subjects working in carbon monoxide had slightly higher heart rates. This report was submitted in fulfillment of Grant ARB-2098, Institute of Environmental Stress, UCSB, under the sponsorship of the California Air Resources Board. Work was completed as of May 31, 1974.
For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753
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