Thermoregulatory effects following exposure to particulate matter in healthy and cardiopulmonary-compromised rats

Epidemiological studies have correlated human exposure to ambient particulate matter (PM) with increased morbidity and mortality, particularly in cardiopulmonary-compromised individuals. We conducted experimental studies using radiotelemetry methodology to examine the effects of PM; exposure in healthy and compromised rats. Examples of ambient, combustion, and natural source particles, along with their primary metallic constituents, were tested in rodent models chosen to simulate human conditions of systemic hypertension, pulmonary hypertension, pulmonary inflammation, and general cardiac stress. Results indicate that PM induces a robust hypothermia, along with significant decreases in cardiac function, leading to arrhythmogenesis and lethality. These results support those of previous epidemiological studies. (C) 2000 Elsevier Science Ltd. All rights reserved.