Consequences of stratospheric ozone depletion and climate change on the use of materials.

Materials used in the exterior of buildings and in construction are routinely exposed to solar UV radiation. Especially in the case of wood and plastic building materials, the service life is determined by their weather-induced deterioration. Any further increase in ground-level solar UV radiation, UV-B radiation in particular, will therefore reduce the outdoor service life of these products. Any increase in ambient temperature due to climate change will also have the same effect. However, the existing light-stabilizer technologies are likely to be able to mitigate the additional damaging effects due to increased solar UV radiation and maintain the outdoor lifetimes of these materials at the present levels. These mitigation choices invariably increase the lifetime cost of these products. A reliable estimate of what this additional cost might be for different products is not available at the present time. Personal exposure to UV radiation is reduced both by clothing fabrics and glass windows used in buildings and automobiles. This assessment describes how the recent technical advances in degradation and stabilization techniques impact the lifetimes of plastics and wood products routinely exposed to solar UV radiation and the protection to humans offered by materials against solar UV radiation.

Correlations between reported and measured ultraviolet radiation exposure of mothers and young children.

Cumulative and intermittent sun exposure are risk factors for skin cancer, highlighting the need to monitor exposure during childhood. There is currently very little available information concerning the accuracy of self-reported levels of sun exposure, particularly for very young children. In this study, UV radiation (UVR) exposure measured by polysulfone dosimeters worn on the wrist was compared with a measure of estimated exposure using a diary based on recall at the end of the 4 day study period and ambient dosimetric measures. Results of the study indicate that the relative UVR exposures expressed as a fraction of daily total ambient received during the 4 day period by young children and mothers are similar. A high level of association was obtained for the estimated levels of exposure between young children and their mothers. Moderate correlations were evident for dosimeter readings of mother and child on weekends with no significant association on weekdays. The association between estimated exposure and dosimeter readings was poor and needs improvement. This may be achieved by greater consideration of structural and environmental factors that influence the levels of UVR exposure received by individuals and by increasing the level of specificity in the measurement instruments. Methodological issues such as recall of exposure after several days, quantity of sun exposure and more precise measurement of grades of exposure when outside may have more impact than previously expected, and further information is being sought with a larger sample for exposure during the summer months.

Direct measurement of sun protection in primary schools.

BACKGROUND: "Kidskin" is an intervention study involving children at 33 primary schools in Perth, Western Australia. This study includes measurement of changes in implementation of schools' sun protection policies. This paper reports on measurement of observable aspects of sun protection. METHODS: Hat use was assessed from videos of children in the playground. Shade use was measured using UVR-sensitive polysulfone badges worn by a random sample of children. Shade provision was measured from aerial photographs of the schools. Principals were surveyed about school policies and practices. RESULTS: Eighty-seven percent of children wore a hat during lunch time at school, although only 14% wore the most protective styles of hats. The mean proportion of ambient UVR exposure received by Year 1 children was 15.5%; children spent less time in the sun on sunnier days. On average, 14.5% of the playground was shaded; this was not associated with children's sun exposure. Correlations between these results and the principals' estimates were poor. CONCLUSIONS: Children should be encouraged to wear more protective styles of hats and to avoid sun exposure, even on less sunny days during spring and summer. Principals' estimates of shade provision and children's sun protection behavior at school are of little value.

Ambient solar UVR, personal exposure and protection.

Ambient solar ultraviolet radiation (UVR) has been monitored around Australia by the Australian Radiation Laboratory (ARL) and its successor ARPANSA since the mid 1980's using a network of radiometric detectors and a spectroradiometer (SRM) for spectral measurements, based in Melbourne. In a continent the size of Australia, the levels vary markedly, basically following a latitude gradient increasing towards the equator but with local geographical and weather effects also evident. ARL also conducts personal exposure studies of various population groups in collaboration with other research centres to gather information on what fraction of the ambient UVR people receive. ARL also undertakes studies on the UVR protection provided by sunscreens, clothing, hats, sunglasses and other materials in an attempt to improve UVR protection used by the public.

Solar UVR exposures of primary school children at three locations in Queensland.

The ultraviolet radiation (UVR) exposures of primary school children in Brisbane, Toowoomba and Mackay (latitudes 27 degrees 30', 27 degrees 33' and 21 degrees 15' south, respectively) were assessed over a period of 2 weeks at each location using UVR-sensitive polysulfone (PS) film badges attached at the shoulder. The students filled in questionnaires on their time spent outdoors for each day of the study. These data in conjunction with the ambient UVR measured by a detector/datalogger unit at each site were used to correlate the calculated exposures with those measured using the PS badges. Overall, the questionnaires indicated that the males spent more time outdoors and had higher measured UVR exposures than females. For both boys and girls at each location, there was a strong correlation between the mean measured UVR exposure and the ambient solar UVR at that location.

Protection against solar ultraviolet radiation.

Interest in protection against solar ultraviolet radiation (UVR) among the general public in Australia has been increasing steadily as a result of the 'SunSmart' campaigns run by the various state cancer councils. This increasing awareness is due in part to the requirements for occupational protection of outdoor workers and to provision of UVR protection for the recreational market. Behaviour outdoors can significantly affect exposure to solar UVR and use of items of personal protection can provide a substantial reduction in the UVR dose received. The protective properties of sunscreens, sunglasses, hats and clothing against UVR have been the subject of considerable research for some time, and over the last few years interest has extended to the provision of shade structures and the UVR protection provided by various commonly used materials. These materials include shadecloth, plastics, glass, windscreens and applicable tints. Australia has rigorous standards covering protection and UVR, in particular for sunscreens [Standards Australia/Standards New Zealand, Sunscreen products-evaluation and classification, Report No. AS 2604, Sydney/Wellington, 1993.], sunglasses [Standards Australia, Sunglasses and fashion spectacles-nonprescription types, Report No. AS 1067.1, Sydney, 1990.], protective eyewear [Standards Australia/Standards New Zealand, Eye protectors for industrial applications, Report No. AS/NZS 1337, Sydney/Wellington, 1992.] and shadecloth [Standards Australia, Synthetic shadecloth, Report No. AS 4174, Sydney, 1994.]. Compliance with the sunglass standard became mandatory in 1988 and UVR protection provided by sunglasses has increased substantially since then. In July 1996 a standard on 'sun protective textiles' [Standards Australia/Standards New Zealand, Sun protective clothing-evaluation and classification, Report No. AS/NZS 4399, Sydney, 1996.] incorporating ultraviolet protection factors (UPFs) and a rating scheme with protection categories, was introduced; this was the first of its kind in the world. Australian Radiation Laboratory (ARL) UPF swing tags with UVR protection advice from the Australian Cancer Society on the reverse side are used to denote the amount of protection against solar UVR provided by clothing. To date in excess of 5 million ARL swing tags have been issued. Work on the various standards is continuing. The maximum allowed 'sun protection factor' (SPF) limit for sunscreens may be increased to SPF 30 + in the near future, and additions to the sun protective textiles standard are also planned. This paper discusses measurement methods, results, the rationale used in formulating the Australian Standards and the current state of UVR protection in Australia.

Assessment of habitual sun exposure in adolescents via questionnaire--a comparison with objective measurement using polysulphone badges.

The reliability and validity of sun exposure questions were examined in a group of 125 schoolchildren aged 14-15 years of northern European ancestry. We compared estimates of erythemally effective dose (EED) obtained from polysulphone badges worn on four consecutive weekend days in late spring to answers to several questions on habitual sun exposure. The polysulphone badge estimates accurately reflected the reported sun exposure of children and were highly correlated with responses to questions on habitual sun exposure obtained 12 months earlier. For the question "During weekends and school holidays, how much time do you usually spend in the sun each day", the Pearson correlation coefficients for the association with EED were 0.36 (girls) and 0.23 (boys). Adjusted for within-person variation in the EED measurements, the correlation coefficients were 0.65 (girls) and 0.43 (boys). For the question "Weekends and school holidays, where do you spend your time", the correlation coefficients were 0.18 (girls) and 0.32 (boys); the adjusted coefficients were 0.30 (girls) and 0.53 (boys). The findings suggest that "habitual' sun exposure in teenage children is a temporally stable behaviour that is reported with an acceptable degree of reliability and validity.

Personal dosimetry of solar UV radiation for different outdoor activities.

Quantifying individual exposure to ultraviolet radiation (UVR) is critical to understanding the etiology of a number of diseases including nonmelanotic and melanotic skin cancers. Measurements of personal exposure to solar UVR were made in Hobart, Tasmania in February (summer) 1991 for six different outdoor activities using UVR-sensitive polysulfone (PS) film attached at seven anatomical sites. Concurrent behavioral and environmental observations were also made. To date many studies have relied on subject recall to quantify past solar UVR exposures. To gain insight into the accuracy of subject recall the measured UVR exposures received by different subjects using the PS film were compared to those calculated from personal diaries and ambient solar UVB levels from a monitoring station. In general, when UVR exposure activities took place under close supervision, good correlations were obtained between the PS badges and the ambient measurements/diaries approach. Ultraviolet radiation exposures for the field study involving 94 subjects engaged in a number of outdoor activities are presented.