Title: Cardiovascular effects of chronic carbon monoxide and high-altitude exposure

Abstract

At higher altitudes, ambient carbon monoxide levels are increasing with the number of residents and tourists and their use of motor vehicles and heating devices (such as fireplaces, furnaces, and stoves). Although chronic exposure to carbon monoxide or high altitude causes pronounced cardiovascular changes in humans as well as in animals, there is little information on the effects elicited by these stressors combined. Data from acute studies and theoretical considerations suggest that carbon monoxide inhaled at altitude may be more detrimental than carbon monoxide inhaled at sea level. It is not known, however, if the cardiovascular system adapts or deteriorates with continuous, concurrent exposure to carbon monoxide and high altitude. Male laboratory rats were exposed for six weeks in steel barometric chambers to altitudes ranging from 3,300 ft (ambient) to 18,000 ft and to concentrations ranging from 0 to 500 parts per million (ppm)2. Carbon monoxide had no effect on body weight at any altitude. There was a tendency for hematocrit to increase even at the lowest concentration of carbon monoxide (9 ppm), but the increase did not become significant until 100 ppm. At 10,000 ft, there was a tendency for total heart weight to increase in rats inhaling 100more » ppm carbon monoxide. Although its effects on the heart at altitude are complex, carbon monoxide, in concentrations of 500 ppm or less, had little effect on the right ventricle; it did not exacerbate any effects due to altitude. There was a tendency for the left ventricle weight to increase with exposure to 35 ppm carbon monoxide at altitude, but the increase was not significant until 100 ppm carbon monoxide. Heart rate, blood pressure, cardiac output, and peripheral resistance were unaffected by exposure to 35 ppm carbon monoxide or 10,000-ft altitude singly or in combination.« less

Authors:

McGrath, J J ^[1]

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+ Show Author Affiliations

1. Texas Tech Univ. Health Sciences Center, Lubbock (USA)

Publication Date:

Sat Jul 01 00:00:00 EDT 1989

OSTI Identifier:

6983227

Resource Type:

Journal Article

Journal Name:

Research Report Health Effects Institue; (USA)

Additional Journal Information:

Journal Volume: 27

Country of Publication:

United States

Language:

English

Subject:

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; CARBON MONOXIDE; TOXICITY; CARDIOVASCULAR SYSTEM; PATHOLOGICAL CHANGES; ALTITUDE; ANOXIA; CARBOXYHEMOGLOBIN; CHRONIC EXPOSURE; ENVIRONMENTAL EXPOSURE; EXPOSURE CHAMBERS; INHALATION; RATS; ANIMALS; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; INTAKE; MAMMALS; OXIDES; OXYGEN COMPOUNDS; RODENTS; VERTEBRATES; 560300* - Chemicals Metabolism & Toxicology