Chemical identity and cardiovascular toxicity of hydrophobic organic components in PM.

Numerous experimental and epidemiological studies have demonstrated that exposure to PM may result in pathogenesis of several major cardiovascular diseases (CVDs), which can be attributed to the combined adverse effects induced by the complicated components of PM. Organic materials, which are major components of PM, contain thousands of chemicals, and most of them are environmental hazards. However, the contamination profile and contribution to overall toxicity of PM-bound organic components (OCs) have not been thoroughly evaluated yet. Herein, we aim to provide an overview of the literature on PM-bound hydrophobic OCs, with an emphasis on the chemical identity and reported impairments on the cardiovascular system, including the potential exposure routes and mechanisms. We first provide an update on the worldwide mass concentration and composition data of PM, and then, review the contamination profile of PM-bound hydrophobic OCs, including constitution, concentration, distribution, formation, source, and identification. In particular, the link between exposure to PM-bound hydrophobic OCs and CVDs and its possible underlying mechanisms are discussed to evaluate the possible risks of PM-bound hydrophobic OCs on the cardiovascular system and to provide suggestions for future studies.