Adult UVR exposure changes with life stage – a 14-year follow-up study using personal electronic UVR dosimeters†
Over a period spanning 14 years (1999–2001, 2006 and 2012), 31 volunteers participated in sun behaviour studies with the same protocol wearing a personal, electronic wrist-borne UVR dosimeter and completed sun exposure diaries resulting in a total of 15 946 measurements days (126 days per person per year). The participants individually maintained their UVR dose level and behaviour over the years. No statistically significant differences were seen from year to year in the “estimated annual UVR dose”, the “mean UVR dose per day”, the “mean percentage of ambient UVR”, “days sunbathing to get a tan”, “days with intermittent exposure” or in “sunburn episodes”. The 20 participants still active in the labour market used sunscreen on more days in 2012 than in 1999 (p = 0.019) and with a significantly higher SPF (sun protecting factor (p < 0.001)) resulting in significantly fewer days with risk behaviour without sunscreen applied in 2012 than in 2006 (p < 0.001) and 1999 (p < 0.003). This was in contrast to the 11 participants who retired during the study period. The retired group received a non-significant 45% higher UV dose in 2012 than in 1999 (p = 0.054). In an additional study, nine 30-year-old indoor workers (high school students in the 1999 study) had changed their sun exposure pattern and had fewer days sunbathing (p = 0.008) and fewer risk behaviour days without sunscreen applied in 2012 than in 1999 (p = 0.002). Conclusion: The participants still active in the labour market maintained their sun exposure behaviour over a 14-year period. The retirees had a higher UVR dose and riskier exposure behaviour after retirement, while the high school students had changed to less risky sun behaviour on becoming indoor workers.