Measurement of the exposure of seamen to UV radiation

Status:

completed 12/2011

Aims:

During work on the decks of seagoing vessels, seamen may be exposed to varying levels of ultraviolet (UV) radiation caused by sunlight, depending upon the route of the vessel, season, time of the day and weather conditions. High UV radiation exposure may cause acute skin damage such as sunburn, and long-term damage such as premature ageing of the skin and skin cancer. The formal recognition of cancer caused by exposure to UV radiation at workplaces as an occupational disease is currently the subject of discussion. The results of exposure measurements are already available for certain occupational groups such as mountain guides, construction workers, agricultural workers, etc. Reliable data on the UV radiation levels to which seamen are exposed would, however, also be valuable. The UV radiation exposure of seamen on a number of different voyages was therefore measured by way of example. The purpose of the data is firstly to determine whether seamen are exposed to higher levels of UV radiation than the wider population. Secondly, they are to provide a basis for the investigation and assessment of UV exposure in formally recognized cases of occupational disease in the future.

Activities/Methods:

A total of four measurement voyages were conducted on typical maritime routes on which high exposure to UV radiation may be anticipated: from Spain to Brazil, from Panama to Belgium, from Slovenia to Singapore, and a tour of the Mediterranean. Stationary measurements were taken, as were measurements on test subjects. Electronic and biological dosimeters were used for this purpose. For the stationary measurements, a support beam bearing dosimeters was fitted to a stand which in turn was erected on the observation deck at a point with no shadow. This enabled the maximum possible UV radiation exposure to be determined. The test subjects were equipped with a belt and headgear to which dosimeters were attached in various positions (chest, shoulders, back and head). Parallel to the measurements, the routes were recorded by means of GPS, and the weather observed.

Results:

As anticipated, the UV radiation exposure is dependent upon the solar zenith angle: radiation increases with increasing proximity to the equator, reaches its peak when the equator is crossed and then falls again. The incident radiation was also found to be dependent upon both the direct solar radiation, and the diffuse sky radiation and the radiation reflected from surfaces (water, superstructure of the vessel).
The measurements on the test subjects showed the head and shoulders to be exposed to the highest levels of UV radiation.
The project succeeded in producing a sound and cohesive body of data. It is therefore planned for these data to be presented in the form of an IFA report and also for them to be used within a follow-up project, enabling cases of suspected occupational disease to be processed properly.

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