The skin is a target organ for pollution and also allows the penetration of exogenous agents into the body. About 700,000 new cases of skin cancer were diagnosed in 1993, and 9100 people died of cancer; 76% of the deaths were due to melanoma. Skin cancers are most closely associated with exposure to UVB (290 to 320 nm) irradiation. For every 1% decrease in ozone there is a 2% increase in UVB irradiance, and therefore a 2% increase in skin cancer is predicted. Therefore the atmospheric pollution by ozone-depleting chemicals is a major concern to dermatologists. In addition to being a target organ and site of neoplasms and contact allergens, the skin is the site of significant absorption of environmental pollutants. In the case of chloroform, the percutaneous absorption is equivalent to the respiratory uptake, emphasizing how important it is to recognize skin absorption in toxicologic exposures.