Influence of meteorological variables upon the UV radiation exposure of workers working outdoors

Status:

completed

Aims:

The weather has a decisive influence upon exposure to ultraviolet (UV) radiation. To date, no scientific studies have been conducted directly linking dosimetric measurements of individuals' UV radiation exposure to meteorological data.

The objective of this research project was to link the results of measurements – obtained over many years by means of GENESIS-UV – of workers' exposure to UV radiation to meteorological data, and to clarify as-yet unresolved issues. These particularly concern the UV index, which is to be examined for its suitability for use by the accident insurance institutions as a possible prevention instrument. The project was also to determine whether measurements obtained with GENESIS-UV enable shadow components during work or periods spent indoors or outdoors to be estimated.

Activities/Methods:

Based upon the UV index (UVI) measured on a static, level surface, proposals are formulated for protective and behavioural measures commensurate with the level. The objective was a scientifically validated conclusion of whether the UV index correctly reflects the actual exposure at the person.

A large body of data has already been built up over the years by means of GENESIS-UV and dosimeters worn on the body for measurement of outdoor workers' exposure to UV radiation. GENESIS-UV supplied data for the timing, UV-A and UV-B/C radiation, three-dimensional data for the acceleration, and three-dimensional data for the (Earth's) local magnetic field.

A meteorological station was used for static measurement of the following parameters directly at the work location of test persons fitted with a dosimeter for GENESIS-UV: UV radiation (global, diffuse, erythema-weighted, spectrally resolved irradiance), temperature, atmospheric humidity, atmospheric pressure, wind speed, precipitation. These measurements were placed in relation to the values measured by the dosimeter worn on the person and were linked to the recorded task profiles by precise logging of the tasks performed. A further key aspect was creation of a meteorological data record. This was to contain parameters such as the precise timing of the sun's path, direct and diffuse solar radiation fluxes, temperature, humidity, wind speed, cloud cover, precipitation and data from the UV monitoring network of the German Federal Office for Radiation Protection. These data were linked to the data records from GENESIS-UV.

The project is linked closely to DGUV research project FF-FB 181, Part 2 of the research project: Malignant skin tumors induced by UV-irradiation – Development and evaluation of differentiation criteria between occupational and non-occupational causes relevant for the occupational health insurance, and the IFA projects 4206, DGUV-FB 181: Skin cancer caused by UV radiation, 4207, Measurement programme employing the GENESIS-UV measurement system: ultraviolet radiation during outdoor tasks, and 4208, UV transmission of vehicle windows.

Results:

In the first milestone, the meteorological station was procured and extended with dosimeters used in the GENESIS-UV measuring system, thus providing a direct link to recordings of the dosimetric data on the insured individual. The meteorological station will remain in use beyond the end of this project for further measurements and for campaigns (such as the sunlight protection days conducted by the individual accident insurance institutions).

A large number of data records were obtained during the 14 measurement tours carried out across Germany in 2016 and 2017. The UV exposure of test persons working outdoors was compared with the global solar UV radiation. The UV Index (UVI) was determined from the global solar UV radiation and compared with the forecasts of the German weather service (DWD). The actual UVI was never overestimated, but showed close agreement with the forecast only under clear skies.

In addition to the measurements conducted at workplaces, a series of measurements was carried out in a project conducted jointly with the University of Jena concerning the irradiation of various parts of the body of beach volleyball players. From the results, the IFA is able to draw conclusions regarding the distribution of irradiation in different body postures. Together with the other data recorded in GENESIS-UV, these conclusions can in turn be incorporated into a project to be conducted jointly with the University of Lausanne. This project is to use software-based modelling to build up a register of the distribution of exposure at different parts of the body among workers in different occupations. Initial model simulations were used to study the influence of cloud cover on the personal UV radiation exposure in a number of anatomical body regions.

In a project conducted jointly with Public Health England (PHE), measurements were taken over several days during a low ozone event. The effect of the ozone mini-hole was quantified by means of the radiation amplification factor (RAF). This was broken down into an RAFm based upon UV measured data and a new parameter, the cloud ozone factor (COF), for the future characterization of ozone mini holes. This enables the elevated UV radiation on a particular day to be quantified.

This project served to support a project funded by a DGUV doctoral scholarship in cooperation with the University of Bonn's meteorological institute. The concluding dissertation, including scientific evaluation, is currently being published by the university.

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