Non-melanoma skin cancer: occupational risk from UV light and arsenic exposure

Non-melanoma skin cancer (NMSC) has a significant impact on public health and health care costs as a result of high morbidity and disfigurement due to the destruction of surrounding tissues. Although the mortality rates of these tumors are low, the high incidence rates determine a considerable number of deaths. NMSC is the most common type of skin cancer, representing about 1/3 of all malignancies diagnosed worldwide each year. The most common NMSC are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Studies on humans and experimental animals indicate that ultraviolet (UV) light and arsenic play important roles in the development of these skin malignancies. Several epidemiological studies have investigated the risk of developing NMSC and the potential link between exposure to sunlight and arsenic in the agricultural and industrial occupational settings. To date, the published literature suggests that there is no apparent skin cancer risk as regards workplace exposure to artificial UV light or arsenic. Concerning UV light from sun exposure at the workplace, most published studies indicated an elevated risk for SCC, but are less conclusive for BCC. Many of these studies are limited by the methodology used in the evaluation of occupational exposure and the lack of adjustment for major confounders. Therefore, further epidemiological studies are required to focus on exposure assessment at the individual level as well as potential interactions with other occupational and non-occupational exposures and individual susceptibility. In doing so, we can better quantify the true risk of skin cancer in exposed workers and inform effective public health prevention programs.