An estimate of the total UV-B exposure for outdoor workers during a south-east Queensland summer

A numerical model was used to calculate the facial UV-B exposure received during summer (December-February) by typical outdoor farm workers in south-east Queensland (27.5 degrees S), a population among the groups at highest risk of skin cancer. The exposure was calculated using new, more detailed measurements of the probability of outdoor activity of farmers (FO-measured by the Fraction of time spent Outside), the distribution of incident solar radiation on the human face (ER-the Exposure Ratio, measured by the fraction of the ambient radiation which falls on each site) and the ambient UV-B levels (AE-the Ambient Exposure) for the region. Only the exposure of unprotected faces was considered. An analysis of the distribution of exposure over a typical working day and of the likely spread of exposures is also presented. The group average of exposures at three facial sites (the forehead, nose and cheek) were 8.7 J cm(-2), 14.0 J cm(-2), and 9.5 J cm(-2), respectively, which is substantially higher than estimates for summer made for populations in more temperate latitudes.