IMPORTANCE UV radiation (UVR) exposure is the primary environmental risk factor for developing cutaneous malignant melanoma (CMM). OBJECTIVE To measure changes in sun behavior from the first until the third summer after the diagnosis of CMM using matched controls as a reference. DESIGN, SETTING, AND PARTICIPANTS Three-year follow-up, observational, case-control study performed from May 7 to September 22, 2009, April 17 to September 15, 2010, and May 6 to July 31, 2011, at a university hospital in Denmark of 21 patients with CMM and 21 controls matched to patients by sex, age, occupation, and constitutive skin type participated in the study. Exposure to UVR was assessed the first and second summers (n=20) and the first and third summers (n=22) after diagnosis. Data from 40 participants were analyzed. MAIN OUTCOMES AND MEASURES Exposure to UVR was assessed by personal electronic UVR dosimeters that measured time-related UVR in standard erythema dose (SED) and corresponding sun diaries (mean, 74 days per participant each participation year). RESULTS Patients' daily UVR dose and UVR dose in connection with various behaviors increased during follow-up (quantified as an increase in daily UVR dose each year; all days: mean, 0.3 SED; 95% CI, 0.05-0.5 SED; days with body exposure: mean, 0.6 SED; 95% CI, 0.07-1.2 SED; holidays: mean, 1.2 SED; 95% CI, 0.3-2.1 SED; days abroad: 1.9 SED; 95% CI, 0.4-3.4 SED; and holidays with body exposure: mean, 2.3 SED; 95% CI, 1.1-3.4 SED). After the second year of follow-up, patients' UVR dose was higher than that of controls, who maintained a stable UVR dose. No difference was found between groups in the number of days with body exposure or the number of days using sunscreen in the second and third years of follow-up. CONCLUSIONS AND RELEVANCE Our findings suggest that patients with CMM do not maintain a cautious sun behavior in connection with an increase in UVR exposure, especially on days with body exposure, when abroad, and on holidays.
Solar ultraviolet radiation (UVR) is known to be the main cause of skin cancer, the incidence of which is rising with national differences across Europe. With this observation study we aimed to determine the impact of nationality on sun behaviour and personal UVR exposure on sun and ski holidays. 25 Danish and 20 Spanish sun-seekers were observed during a sun holiday in Spain, and 26 Danish and 27 Austrian skiers were observed during a ski holiday in Austria. The participants recorded their location and clothing in diaries. Personal time-logged UVR data were recorded as standard erythema doses (SEDs) by an electronic UVR dosimeter worn on the wrist. Danish sun-seekers were outdoors for significantly longer, received significant higher percentages of ambient UVR, and received greater accumulated UVR doses than Spanish sun-seekers. Danish skiers were also outdoors for significantly longer than Austrian skiers, but the behaviour of the Danish skiers did not result in significantly greater accumulated UVR doses. Both Danish and Spanish sun-seekers and Danish and Austrian skiers received substantial UVR doses. The behaviour's influence on the UVR doses received by the Danish participants may indicate an explanation of the higher skin cancer incidence among Scandinavians compared with other European populations.
OBJECTIVE: To assess individual time-related (time-stamped) UV radiation (UVR) dose pattern and sun exposure behavior. DESIGN: Open prospective observational study. SETTING: University hospital.Study Subjects Two hundred eighty-five Danish volunteers with apparently healthy skin: children, adolescents, indoor workers, sun worshippers, golfers, and gardeners (age range, 4-68 years).Measurements We developed a personal electronic UVR dosimeter in a wristwatch (SunSaver) and measured continuously time-related UVR doses in standard erythema dose (SED) and corresponding sun exposure behavior from diaries, resulting in 346 sun-years (median, 119 days). The estimated yearly UVR doses were calculated based on personal and ambient measured doses. RESULTS: The median estimated yearly UVR dose was 173 SEDs (range, 132 SEDs [indoor workers]-224 SEDs [gardeners]), with no significant difference by age (P =.25) or sex (P =.75). The SED of girls (175 SEDs) was significantly (P =.04) higher than that of boys (116 SEDs). Subjects younger than 20 years had an increase of 5 SEDs per year (P =.03). Sunbathing or exposing shoulders (risk behavior) outside the beach resulted in a median of 2.5 SEDs per day in northern Europe and 3.2 SEDs per day in southern Europe; however, at the beach, corresponding values were 4.6 and 6.9 SEDs per day. Children and adolescents received more than half their total UVR dose at the beach. Sunburning doses above 10 SEDs per day were connected with sunbathing or exposing shoulders. Of the UVR dose, 50% was received between noon and 3 PM. Only the gardeners received most of their UVR dose (55%) on working days. CONCLUSIONS: High UVR doses are connected with risk behavior, except for outdoor workers. There is no need to change sun exposure habits on days without risk behavior.
The influence of the summer UVR exposure on serum-25-hydroxyvitamin D (25(OH)D) in late summer and winter was investigated in an open study on 25 healthy, adult volunteers. The UVR exposure dose in standard erythema dose (SED) was monitored continuously during a summer season with personal, electronic wristwatch UVR dosimeters and sun exposure diaries. Constitutive and facultative skin pigmentation was measured in September. 25(OH)D was measured in September and February and was in mean 82 nmol/L +/- 25 (mean +/- SD) in September and 56 nmol/L +/- 19 (mean +/- SD) in February. The received cumulative UVR dose measured during a mean of 121 days was 156 SED +/- 159 (mean +/- SD). The following UVR exposure parameters correlated with 25(OH)D in September and February, respectively: (1) The cumulative UVR dose (r = 0.53; P