We’ve talked before on this blog about West Virginia University research that found rats exposed to dust from mountaintop removal communities showed changes in the diameter of blood vessels, which could in turn reduce blood flow. The research is among the work going on now that aims to explain the findings of WVU’s Michael Hendryx that residents living near mountaintop removal sites face greater risks of serious disease, including cancer and birth defects.
Well, the full scientific paper on this issue is out now. You can read the abstract here, but the full paper is available by subscription only I’m afraid. Here’s the abstract:
Air pollution particulate matter (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 mountaintop mining (MTM)-derived PM (PM-MTM) are unclear, but must be identified in order to establish causal effects.
PM was collected within 1 mile of an active MTM site in southern West Virginia. The PM was extracted and was primarily <10 μm in diameter (PM10), consisting largely of sulfur (38%) and silica (24%). Adult male rats were intratracheally instilled (IT) with 300 μg PM-MTM. Twenty-four hours following exposure, rats were prepared for intravital microscopy, or isolated arteriole experiments.
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 perivascular nerve stimulation (PVNS)-induced vasoconstriction in exposed animals compared to sham.
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.
Why is all of this important? Here’s what the study authors, led by WVU’s Travis Knuckles, said about that:
Pulmonary PM exposure is a potent contributor to cardiovascular morbidity and mortality. PM point sources, such as mountaintop mining sites, can contribute significantly to the overall particle concentration. We have demonstrated that PM collected from populated areas with several active mine sites has the potential to adversely affect microvascular reactivity. This is the first investigation that has identified PM from mountaintop mining operations as a microvascular toxicant. If our findings translate into human outcomes, this may account or contribute to the known cardiovascular health disparities frequently observed in this unique population.