Impact of particulate matter exposition on the risk of ischemic stroke: epidemiologic evidence and putative mechanisms.

Ambient particulate matter (PM) pollution is estimated to be responsible for 3.2 million deaths annually worldwide. Although many studies have demonstrated PM as a serious risk factor for cardiovascular diseases, less is known on its association with cerebrovascular events. Over the last decade, however, an increasing number of studies have provided data showing a relationship between PM exposure and ischemic stroke (IS). In this article, we will report on existing epidemiologic findings for an association between PM exposure and IS based on a systemic literature search. Thus, despite inconsistencies in the results, currently available data suggest that PM exposure is a risk factor for IS, especially in patients with preexisting illnesses. With regards to the mechanisms leading to PM-dependent vascular damage, in particular proinflammatory, prooxidative, as well as proatherogenic pathways have been suggested to be involved. Notably, to date there is only one study published, which demonstrates the influence of PM exposure on cerebrovascular function. We will discuss reasonable approaches for future neurovascular research in this field.