Urbanization, Environmental Pollution and Skin Aging

Abstract

The skin aging process, which is induced by environmental factors, is named premature or extrinsic skin aging process and can be distinguished from the chronologically (intrinsic) skin aging process by characteristic skin aging signs. Although human skin acts as a biological shield against pro-oxidative chemicals and physical air pollutants, prolonged or repetitive exposure to high levels of these pollutants may have profound negative effects on the skin. Gender differences in toxicity have been reported for many substances. Children are known to be more vulnerable to the adverse health effects of air pollution. Environmental pollution by traffic is also associated with the occurrence of signs of extrinsic skin aging. Heavy metals such as cadmium, lead and mercury are common air pollutants that pose health hazards due to bioaccumulation. Ozone in the stratosphere has protective effects by filtering solar UV radiation; however, in the troposphere ozone has toxic implications for skin. Due to paucity of scientific evidence, there are no established guidelines currently available for protecting the skin against air pollution. Aside from reducing exposure, potential protection strategies should focus on repairing the skin barrier, replenishing antioxidant reserve, and reducing inflammation caused by air pollutants.