04.11.2025 BOKU-Met Seminar
The approval of actinic keratosis or squamous cell carcinoma as occupational diseases depends on the received annual occupational ultraviolet radiation (UVR) exposure. The estimation of the annual occupational UVR exposure bases on daily personal UVR exposure measurements in conjunction with ambient UVR measurements for the determination of the “Exposure Ratio to Ambient” (ERTA). The ERTA can be used to transfer personal UVR exposure measurements to other dates/locations and can be applied for estimations of annual occupational UVR exposure.
To derive meaningful data from temporally arbitrary personal UVR exposure measurements is challenging. Beside the requirements on measuring equipment in a harsh environment and mounting (intensive movements), the duration of measurements has to be considered. Working hours of outdoor workers are rather variable and flexible compared to others. Nevertheless, companies respectively working contracts specify the work-time model which includes the normal working hours (start and end time) and these should be met in general. These are also the official base for all kind of considerations like approving an occupational disease for a worker. Personal UV exposure measurements campaigns cannot cover all cases of real occurring work time models. Therefore, it is often necessary to recalculate measured UVR exposure to the normal working hours (standard workday).
While ERTA is suitable for recalculations, it cannot always be determined directly. In practice, mismatches between the measuring periods of personal and ambient UVR exposure measurements can occur. In some cases, ambient UVR exposure measurements may not have been conducted at all and must be substituted with, for example, total daily values.
In this work, we will present a method - together with its validation - that enables to recalculate UVR exposure measurements made over any period during the day to any declared standard workday with high degree of accuracy, even if ERTA cannot be determined directly. Further, we will care on the estimation of annual personal UV exposure. The annual exposure depends on several factors like the number of working days, days off (leave days, public holiday etc.) and working hours. We will run some realistic scenarios for Vienna, Austria, starting with temporally arbitrary personal UVR exposure measurements during different working hours within the day. After recalculation to a declared standard working day and the determination of the ERTA, the annual exposure will be calculated for different work time models and number of days off.