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For some years, the German Social Accident Insurance Institution for Transport and Traffic has observed a clear increase in reported cases of skin cancer among seamen. Seamen on deck duty in merchant shipping and the fishing industry are primarily affected. They are exposed during work on deck to varying levels of UV radiation, depending upon the route of the vessel, season, time of the day and weather conditions. Reliable data on the level of this radiation were not previously available. Four measurement voyages were therefore conducted on typical international shipping routes on which high UV radiation exposure is encountered. The individual UV radiation exposure was determined over several weeks and in a number of climate zones by means of personal measurements. Static UV radiation exposure levels on deck were also measured. A job-exposure matrix was produced. The duration of the voyages, length of time spent on deck, typical zones traversed, etc. were described in this matrix for a range of tasks and occupations. The matrix is to be used in conjunction with the measured UV exposure values in order for individuals' UV exposure doses to be determined as precisely as possible during investigations of cases of suspected occupational disease. Interpretation of the measured values enables conclusions to be drawn regarding the daily UV radiation exposure dose. As expected, the results were seen to depend upon the solar zenith angle, i.e. radiation increases with decreasing latitude. Radiation also occurs both directly from the sun, and in the form of diffuse radiation from the sky and reflection from surfaces (superstructure of the vessel). The personal measurements on the test subjects showed exposure to UV radiation to be highest on the head and shoulders. Model analyses of the measured results were performed in conjunction with the DWD, Germany's national meteorological service. Calculations of the erythemal radiation level were compared with the results of measurements taken on the routes of the vessels. The model analyses yield general information on maximum anticipated values; these are exceeded by the measured values only under exceptional meteorological conditions. The project has succeeded in producing a sound and cohesive body of data. The data are to be edited in a follow-on project such that they can be used in conjunction with a future model for computerized estimation of the personal erythemal radiation dose for appropriate processing of cases of occupational disease. |