REDUCING HUMAN EXPOSURE TO SOLAR ULTRAVIOLET RADIATION

J. C. Wong¹, I. Cowling¹, A. V. Parisi²

¹Center for Medical and Health Physics, Queensland University of Technology, GPO Box 2434, Brisbane Q. 4001, Australia

²Center for Astronomy and Atmospheric Research, Faculty of Sciences, University of Southern Queensland, Toowoomba, Q. 4350, Australia

Abstract

Methods for reducing human exposure to solar ultraviolet radiation may not provide the expected degree of reduction in exposures with resultant undesirable effects which could be harmful. This paper examines the use of strategies for campaigns against skin cancer. It was shown that outdoor activities conducted before 10:00 am or after 3:00 pm may reduce the exposure by about 50 %. The choice of UV-protective clothing should look for fabrics with high weight and compact weaving. Hats with a brim size up to 12 cm could reduce the exposure to less than 10 % of the ambient radiation on the forehead only. The protection of the hat for the lower part of the face is negligible (less than 10 % reduction in exposure). A flat shade-structure reduces the exposure to about 30 % of the natural ambient radiation at a height equal to the smallest dimension of the shade-cloth. In a greenhouse, the shoulder of a gardener could receive a cumulative exposure of 2.8 MED over a fortnight, in spring, if he works 2 hours per day, for 5 days in a week. A well planned strategy using a combination of protective methods can minimize the level of exposure to harmful solar radiation.