ABSTRACT
OBJECTIVE: Air pollution PM is associated with cardiovascular morbidity and mortality. In Appalachia, PM from mining may represent a health burden to this sensitive population that leads the nation in cardiovascular disease, among others. Cardiovascular consequences following inhalation of PM(MTM) are unclear, but must be identified to establish causal effects. METHODS: PM was collected within 1 mile of an active MTM site in southern WV. The PM was extracted and was primarily <10 µm in diameter (PM10), consisting largely of sulfur (38%) and silica (24%). Adult male rats were IT with 300 µg PM(MTM) . Twenty-four hours following exposure, rats were prepared for intravital microscopy, or isolated arteriole experiments. RESULTS: PM(MTM) exposure blunted endothelium-dependent dilation in mesenteric and coronary arterioles by 26%, and 25%, respectively, as well as endothelium-independent dilation. In vivo, PM(MTM) exposure inhibited endothelium-dependent arteriolar dilation (60% reduction). α-adrenergic receptor blockade inhibited PVNS-induced vasoconstriction in exposed animals compared with sham. CONCLUSIONS: These data suggest that PM(MTM) exposure impairs microvascular function in disparate microvascular beds, through alterations in NO-mediated dilation and sympathetic nerve influences. Microvascular dysfunction may contribute to cardiovascular disease in regions with MTM sites.
Subject(s)
Air Pollutants/toxicity , Coal Mining , Microcirculation/physiology , Particulate Matter/toxicity , Vascular Diseases/etiology , Animals , Appalachian Region , Arterioles/physiopathology , Coronary Circulation/physiology , Endothelium, Vascular/physiopathology , Male , Metals/toxicity , Microscopy/methods , Rats , Rats, Sprague-Dawley , Splanchnic Circulation/physiology , Vascular Diseases/physiopathologyABSTRACT
PURPOSE: To determine if chronic cardiovascular disease (CVD) mortality rates are higher among residents of mountaintop mining (MTM) areas compared to mining and nonmining areas, and to examine the association between greater levels of MTM surface mining and CVD mortality. METHODS: Age-adjusted chronic CVD mortality rates from 1999 to 2006 for counties in 4 Appalachian states where MTM occurs (N = 404) were linked with county coal mining data. Three groups of counties were compared: MTM, coal mining but not MTM, and nonmining. Covariates included smoking rate, rural-urban status, percent male population, primary care physician supply, obesity rate, diabetes rate, poverty rate, race/ethnicity rates, high school and college education rates, and Appalachian county. Linear regression analyses examined the association of mortality rates with mining in MTM areas and non-MTM areas and the association of mortality with quantity of surface coal mined in MTM areas. FINDINGS: Prior to covariate adjustment, chronic CVD mortality rates were significantly higher in both mining areas compared to nonmining areas and significantly highest in MTM areas. After adjustment, mortality rates in MTM areas remained significantly higher and increased as a function of greater levels of surface mining. Higher obesity and poverty rates and lower college education rates also significantly predicted CVD mortality overall and in rural counties. CONCLUSIONS: MTM activity is significantly associated with elevated chronic CVD mortality rates. Future research is necessary to examine the socioeconomic and environmental impacts of MTM on health to reduce health disparities in rural coal mining areas.
