Bacillus subtilis spore film dosimeters in personal dosimetry for occupational solar ultraviolet exposure

Objective: Ultraviolet (UV) radiation is noted to be one of the most important risk factors for non-melanoma and melanoma skin cancers. The recent development of a spore film test chamber containing spores of Bacillus subtilis resulted in a new method of UV measurement with a spectral sensitivity profile similar to erythema-weighted data calculated from spectroradiometric measurements. Methods: The practical application of dosimeters was tested on 11 persons for 43 days, under different conditions of UV exposure in five different geographical regions. Four professional lifeguards at a public swimming pool carried dosimeters attached to their shoulders or to their caps, for 11 days. Three mountain guides attached dosimeters laterally to their heads on 27 different occasions of mountaineering activity in different mountain regions. Four ski instructors carried lateral head dosimeters during eight days of skiing in the Alps. Results: The life guards received daily UV exposures ranging from 3.6 to 9.5 minimal erythema doses (MED) (mean 5.9, SD ± 1.9). The mountain guides had personal daily UV exposures of from 4.4 to 17.1 MED (11.9 ± 3.9) and ski instructors from 2.8 to 8.8 MED (6.1 ± 1.8). Conclusions:Bacillus subtilis spore film dosimeters can be applied effectively for personal solar UV measurements of occupationally exposed persons, such as lifeguards, mountain guides and ski instructors. UV levels in these occupations exceed international limits of exposure.