ABSTRACT

The risk to outdoor workers of exposure to solar ultraviolet radiation (UVR) has been known for some time, particularly in the building and construction industry, where workers often use little in the way of protection against solar UVR. In recent years there have been attempts by authorities in Australia and in Queensland in particular, where UVR levels in spring and summer are very high to extreme, to instigate and to encourage the use of personal UVR protection by outdoor workers. To quantify UVR exposure of building and construction industry workers involved in typical outdoor work, a study was conducted using UVR-sensitive polysulphone film badges. The results indicated that the doses were significant, often well in excess of recommended exposure limits. The measured exposures varied between trades. Data on the use of personal UVR-protective equipment and the skin type of workers were also collected. Many of the workers had skin types that were sensitive to UVR and showed signs of sunburn. In summary, the study found that at-risk individuals were exposed to extreme levels of UVR, in most cases without adequate and appropriate sun protection.

Abbreviations: CIE, Commission International d E'clairage; EED, erythemally effective dose; EL, exposure limit; ICNIRP, international Commission on Non-Ionizing Radiation Protection; PPE, personal protective equipment; PS, polysulphone; SED, standard erythemal dose; SPD, spectral power distribution; SPF, sun protection factor; UPF, ultraviolet protection factor;UVR, ultraviolet radiation; WHO, World Health Organization.


INTRODUCTION

Australia has high ambient levels of solar ultraviolet radiation (UVR), attributed mainly to its geographical position, with the mainland covering the latitude range 10[degrees]S-38[degrees]S. As a result, Australia has very high skin cancer rates, particularly in the northern state of Queensland (1-3). The World Health Organization (WHO) has recommended that for latitudes between 30[degrees]N and 30[degrees]S sun protection should be used all year round (4). These recommendations would apply to Queensland, which is located between 10[degrees]S and 28[degrees]S (Brisbane is 27.5[degrees]S and Cairns is 17[degrees]S). Educational campaigns run by the various state Cancer Councils have attempted to change the sun-exposure behavior of the population and have had considerable success in raising awareness of the hazards and in affecting behaviour (5-7). In Queensland, occupational exposure to UVR, whether from artificial or solar sources, is a risk that employers and self-employed individuals are legally obliged to control (8). Outdoor workers are a group that receives regular and significant solar UVR exposures (9-11). However, measures to help reduce the UVR exposures of outdoor workers by the use of personal protective equipment (PPE) such as hats, clothing, sunscreens and sunglasses (often provided by employers) have not been well adopted in the building and construction industry. A recent test case that supported the rights of workers who work in the sun for all or part of the day to claim a tax deduction (12) for sun protection items purchased may help improve the situation. Employers now do not have to pay fringe benefits tax when these items are provided for workers.

The National Health and Medical Research Council of Australia adopted the exposure limits (EL) (13) of the International Radiation Protection Association in its occupational UVR exposure standard (14) in 1989. Subsequently, these UVR EL were adopted and reissued by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) in 1999 (15). The occupational EL is a maximum personal dose of 30 J m^sup -2^ of UVR, weighted for the spectral characteristics of the radiation. Occupational exposure includes exposure to artificial sources of UVR and also applies to exposures of outdoor workers to solar UVR.

A number of previous studies have measured the solar UVR exposures of outdoor workers. Larko and Diffey (16) found that outdoor workers received 10-70% of ambient UVR depending on the amount of work time spent outdoors, whereas indoor workers received 6% of ambient UVR in summer, comparable with a study that found that indoor workers received 2-4% of ambient UVR (17). Holman et al. (9) examined the anatomical distribution of UVR exposures for five occupations and for a range of outdoor recreational activities. They found that a classroom teacher received 7-11% of ambient UVR, whereas physical education teachers received 30-50% and other outdoor workers (a gardener, a roof carpenter and a bricklayer) received 44-85% of ambient UVR. Herlihy et al. (10) found that gardeners had UVR exposures of 11% of ambient on the chest and 24% on the back, whereas physical education teachers, groundsmen and lifeguards had measured UVR exposures of 8-9% of ambient on the chest (11). The measured anatomical distributions of solar UVR varied with activity (9,10). Ocular exposures of outdoor workers (fishermen, landscape workers and construction workers) were found to vary between 2% and 17% of ambient levels and were significantly reduced by wearing hats and also showed seasonal variation (18).