In 1775, Sir Percival Pott reported an increased risk of Squamous Cell Carcinoma (SCC) of the scrotum in English chimney sweeps exposed to coal-tar products. Other chemical carcinogens can also promote the development of non-melanoma skin cancer. If a long and intensive enough exposure to those chemicals is given at the work place, an occupational skin disease can be induced.
However, there is an increased exposure to natural and artificial UV light at many work places, exposure to which could theoretically induce skin cancer, too. But according to epidemiological studies, the situation for UV-light induced skin cancer is much more difficult. For the recognition of an occupational skin cancer, one requisite is that the occupational UV exposure must at least double the risk (RR > 2). Today there is not enough scientific and epidemiological evidence for all types of skin cancer to support the idea of recognizing UV-induced skin cancer as an occupational disease. Taking recent publications into consideration, we came to the conclusion that epidemiological proof of an at least doubled risk (RR > 2) due to occupational UV-radiation can only be given for squamous cell carcinoma (Drexler & Diepgen 2000). The clear dose response relationship supports these epidemiological findings. For the individual risk assessment, an attributive UV-radiation < 40% due to occupational factors is needed. Under these circumstances, squamous cell carcinoma should be recognized and compensated for as an occupational disease.
There is a paradoxical relationship with work-related exposure to sunlight in that there appears to be a lower risk of melanoma in outdoor workers compared to indoor workers. For melanoma, the reason for this is that episodic UV exposure is more dangerous than continual UV exposure. Also selection bias could have distorted the association between occupational sun exposure and skin cancer. Outdoor workers tend to be a self-selected group with fewer of the established phenotypic risk factors for skin cancer and melanoma than in other occupations, thus explaining the lower than expected risk of skin cancer and melanoma among outdoor workers.
All outdoor workers should, however, use our current knowledge to develop compensation strategies, such as wearing protective clothing and using sun screens. Also a regular skin check is strongly recommended.