Ultraviolet radiation exposure in children, behavioral factors associated with measured doses and seasonality

Abstract

BACKGROUND AND AIM Ultraviolet radiation (UVR) exposure is associated with both positive and adverse health, such as beneficial aspects of vitamin D and skin cancer, respectively. Childhood is a time of great variability for sun behaviours and increased sensitivity to UVR. However, the relationship between one’s received exposure and the level of ambient UVR is modified by activities. There is a need to document UVR exposure in relation to concurrent activities and sun protection behaviour for children and adolescents. While several studies have measured UVR exposure in children there has been no study conducted in Switzerland, where skin cancer incidence is one of the highest in Europe. METHODS UVR was measured in children aged 4-17 years (n=120) over 5 consecutive days using dosimeters worn on the chest. The dosimeter included an acceleration sensor, to identify periods during which it was worn. During measurement of UVR parents recorded children's activities in activity diaries. Measurements were related to reported activities and mean exposure (and spread) was assessed by activity type and season. RESULTS 4'058 hours of exposure measurements was assessed. The measured mean cumulative daily exposure was 0.46 standard erythmal dose (SED) per participant. The largest contribution to the total cumulative dose came from activities that involved playing outdoors (83.4 SED), followed by walking (32.6 SED), and hiking (25.7 SED), which had the highest mean exposures. The mean exposures were higher during midday hours and at higher altitudes; however, did not evidently vary by season during the measurement period. CONCLUSIONS Children’s UVR in Switzerland varies considerably by activity and whereabouts, and is highest during midday and early afternoon hours, with only modest variation between seasons. While measured UVR intensities are similar for different outdoor activities, the largest contribution to received doses comes from playing outdoors. KEYWORDS Ultraviolet radiation exposure, children, exposure assessment