DGUV-FB 181 governing skin cancer caused by UV radiation

Status:

completed 06/2016

Aims:

Exposure to ultraviolet radiation is without a doubt the most significant risk factor for the incidence of non-melanocytic skin cancer such as actinic keratoses, squamous-cell carcinomas and basal-cell carcinomas. According to current scientific knowledge, squamous-cell carcinomas correlate more closely to the cumulative lifetime radiation dose, whereas basal-cell carcinomas appear to be associated more strongly with intermittent radiation exposure.

Employees at many outdoor workplaces are exposed to considerably higher ultraviolet radiation than the population as a whole. Despite the continual rise in recent years in the numbers of reported cases of occupational disease in the form of skin cancer caused by ultraviolet radiation, non-melanocytic epithelial skin tumours induced by ultraviolet radiation have not been included in the list of occupational diseases formally recognized as such in Germany. With publication in 2013 of the scientific reasoning of the medical advisory council for occupational diseases at the German Federal Ministry for Labour and Social Affairs, this is set to change. Formal recognition of skin cancer caused by natural UV radiation as an occupational disease in the sense of the German Social Code Vol. VII, Section 9 (2) is thus now possible.

During investigations into suspected cases of occupational disease, their recognition as such is dependent upon the medical and occupational conditions being met. The latter condition is met when the ultraviolet radiation during the insured period exceeds a certain component with reference to the mean radiation exposure of the general population. For precise quantification of historical exposure, the German Social Accident Insurance Institutions have at their disposal only the instruments that were developed in a previous project (DGUV occupational diseases research project 170 on skin cancer caused by UV radiation, Part 1). In addition, primary prevention measures and measures in accordance with Section 3 of the German Ordinance on Occupational Diseases (BKV) are not yet available; nor have broad-based studies been conducted by the accident insurance institutions themselves into the acceptance of in-plant measures for protection against solar radiation.

The objectives of this project are on the one hand to validate the instruments for the recording of exposure and to formulate task-specific workplace descriptions in relation to the associated exposure to solar radiation, and on the other to develop primary prevention measures and prevention measures in accordance with Section 3 of the BKV.

Activities/Methods:

In accordance with the study design, the intention was for the occupational histories of a total of 2,400 test subjects to be recorded in nine study centres. The occupational histories were recorded by the accident insurance institutions involved in the study. The IFA was fully responsible for planning and logistics of the study and for analysis of its results. This particularly includes:

• Development of a software program for recording the occupational histories
• Putting into place the required technical infrastructure in the study centres and at the accident insurance institutions
• Training of the accident insurance institutions in use of the software in order to ensure consistency in recording of the occupational histories
• Coordination of the study's performance in conjunction with the other parties to the joint project
• Storage, pseudo-anonymizing and if applicable clustering of the data in a database structure

The data were analysed with regard to:

• Task-specific behavioural patterns
• Ascertainment of the proportion of time spent outdoors
• The insured individuals' assessment of the non-insured exposure component over their entire lives

Results:

In conjunction with the accident insurance institutions, a software application was developed for recording workers' occupational histories. The software implements the requirements set out in the IFA's technical information document on the handling of cases of skin cancer caused by UV radiation. During the project term, the new formally recognized occupational disease BK No 5103, squamous-cell carcinomas of the skin or multiple actinic keratoses of the skin caused by natural UV radiation, was included in the list of formally recognized occupational diseases. The software for recording the occupational histories was therefore developed further directly into an IFA case history software program (radiation case history software), and was thus able to be transferred directly from research activity to the field.

In the course of the project, the software was used to compute the occupational exposure of 2,400 test subjects. Logistically, these test subjects were distributed among eight clinical study centres in Germany (reduced in number by one following merging of the contingents of Bonn and Bochum in Bonn, in deviation from the original plan). In the first part of the consultation, each test subject was examined medically by a doctor. In the second part, they were interviewed by a member of the prevention service's staff with regard to their occupational history. To assure clear and structured performance of the consultation, one accident insurance institution was assigned as a "mentor" to each medical study centre and was responsible for conducting the interviews. In order to assure uniform interviewing, each centre was equipped by the IFA with PC systems on which the occupational history recording software was installed. The prevention service employees were trained in use of the software by IFA staff on real test subjects in preparatory courses.

The radiation exposure data determined in this way were forwarded to the research management in Dresden and then combined with the observations recorded by the doctors in the study.

A further task was metrological validation of the survey instruments from the preceding project, DGUV FF-FB 170, which also included the principles for the software described above (Wittlich formula). Originally, plans were for a sub-set of 600 test subjects to be recruited from the total of 2,400 test subjects in the main study for exposure measurements involving GENESIS-UV during occupational tasks. However, owing to the age structure of the test subjects, most of whom were already of retirement age, and the time constraints of the project, this was not possible. Instead, the accident insurance institutions recruited a further 600 test subjects of their own who were monitored by the use of dosimeters during the measurement campaigns in 2014 and 2015 and were also interviewed with the aid of the occupational history recording software. This allowed the measured and calculated exposure values to be linked directly to each other.

If exposure were presented correctly by calculation from the technical information and by means of the Wittlich formula in its current form, it could be expected to correlate with the measurements with only minor deviations. Analysis revealed there to be virtually no demonstrable statistical correspondence between calculation and measurement. This can be attributed to the strong dependency of the measured radiation upon the occupation and task: the occupational group with the highest exposure is exposed over the year around 15 times as strongly as the occupational group with the lowest measured exposure. Up to now, the calculation has assumed a common reference value for all occupations.

The outcomes of the project were production of an occupational history software application for routine use by the accident insurance institutions, and the results of research project DGUV FF-FB181 obtained jointly with the medical research partners. Measurements in the sister projects employing GENESIS-UV have now also permitted comparison between measurement and calculation, the associated creation of a job-exposure matrix, and further development of the criteria for the assessment of cases of occupational disease BK No 5103.

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