Extrinsic skin aging and air pollution

Skin aging is influenced by two different processes: general ageing, which is genetically determined and occurs as a factor of passing time (intrinsic skin aging), as well as environmental aging (extrinsic skin aging). For decades the former has been associated to chronic exposure to solar radiation and, more recently, tobacco smoke. Very recent epidemiological studies, however, have demonstrated a strict association between skin aging and air pollution (traffic related airborne particles in particular). A direct relation between airborne particulate matter (PM) and skin pigment spots (affecting face, hands dorsal aspects and forearms) has been demonstrated. The pathogenetic mechanisms through which ambient PM exerts its skin ageing effects are different: reactive oxygen species (ROS), mitochondrial damage, and releasing of polycyclic aromatic hydrocarbons, which are adsorbed by the surface of suspended PM.