Elisabeth Thieden

The wrist is a reliable body site for personal dosimetry of ultraviolet radiation

The purpose of this study was to investigate the reliability of measuring solar ultraviolet radiation (UVR) doses with personal UV dosimeters worn on the wrist. Individual solar UVR exposure was measured over one day under standardised conditions (One‐day Beach Study), and over an extended period of time with varying UV exposure and activities (Holiday Study). Dosimeters of a UV‐sensitive spore‐film filter type (VioSpor®) were placed on the right wrist and on the top of head of the test subjects. The wrist was chosen as being a practical position for personal dosimetry and the head position as an internal control for maximal personal UV doses. The One‐day Beach Study took place in the vicinity of Copenhagen in June 1998 over 5 h and included 11 subjects. The Holiday Study included 9 subjects during a period with a mean of 14 days in Scandinavia and Europe from June to September 1998. The head position received the highest UV dose in all subjects in both studies. In both studies, despite considerable individual variation, the mean wrist dose was the same (50%) of that received on the head, although the wrist dose correlated significantly with head dose (P<0.01) only in the Holiday Study. We conclude that the wrist position is a practical and convenient body site for personal dosimetry, yielding reliable results in group exposure studies.

Ultraviolet exposure patterns of Irish and Danish gardeners during work and leisure

Background  Skin cancer, caused by solar ultraviolet (UV) radiation, is a growing problem in Europe. Reliable data on occupational exposure of outdoor workers are needed to develop protective strategies.

Sunbed Radiation Provokes Cutaneous Vitamin D Synthesis in Humans—A Randomized Controlled Trial

We wanted to investigate whether the use of sunbeds with sunlamps emitting mainly UVA and only 0.5% or 1.4% UVB will increase the level of serum 25‐hydroxyvitamin D (25(OH)D). In a randomized, controlled, open study on healthy, Caucasian females (>50 years) sunbed radiation was given as follows: four 6‐min sunbed sessions (days 0, 2, 4 and 7) and four 12‐min sunbed sessions (days 9, 11, 14 and 16 ) with sunlamps emitting 0.5% UVB (n = 20) or with sunlamps emitting 1.4% UVB (n = 15). The controls (n = 21) had no intervention. Serum levels of 25(OH)D were measured on days 0, 9 and 18 in all three groups. The average increase in serum 25(OH)D from day 0 to day 9 was 12 nmol L−1 (SD 11 nmol L−1, P = 0.0002) in the 0.5% UVB group and 27 nmol L−1 (SD 9 nmol L−1, P < 0.0001) in the 1.4% UVB group. From day 9 to day 18 a further but not significant increase in serum 25(OH)D of 3 nmol L−1 (SD 9 nmol L−1, P = 0.2) in the 0.5% UVB group and 0.6 nmol L−1 (SD 18 nmol L−1, P = 0.9) in the 1.4% UVB group was seen. No significant changes were found in the control group. Increasing with UVB dose and exposure time, 37–64% of the sunbed sessions resulted in side effects such as erythema or polymorphic light eruption. The results showed that sunbeds emitting 0.5% and 1.4% UVB increased 25(OH)D serum levels. The increases were dose dependent but reached a plateau after few sessions. Sunbed use as vitamin D source is, however, not generally recommendable due to the well‐known carcinogenicity and high frequency of acute side effects.

Vitamin D Level in Summer and Winter Related to Measured UVR Exposure and 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 < 0.01) and (r = 0.43; P = 0.03); (2) Mean daily hours with UVR measurements monitored by the dosimeter (r = 0.64, P = 0.001) and (r = 0.53; P = 0.007); (3) Days “with sun‐exposed upper body” (r = 0.58, P = 0.003) and (r = 0.50; P = 0.01); (4) Facultative pigmentation (r = 0.47; P < 0.02) and (r = 0.7; P < 0.001); (5) Constitutive pigmentation (r = 0.06, n.s.) and (r = 0.43, P = 0.03). Neither days “sunbathing” nor days with “sunscreen applied” correlated with 25(OH)D. The fall in 25(OH)D during winter was dependent on the entry value.

Solar UVR exposures of indoor workers in a Working and a Holiday Period assessed by personal dosimeters and sun exposure diaries.

Background/Aim: The aim of this study was to quantify ultraviolet radiation (UVR) exposure of fully employed indoor workers during a Working Period and a Holiday Period in the summer months. A further aim was to investigate the correlation between individual personal UVR dosimeter reading and self‐reported data in a diary about sun exposure habits and to investigate whether skin type, age and gender influence sun exposure.

Skin autofluorescence as a biological UVR dosimeter.

Background/Purpose: Collagen is one of the major endogenous skin fluorophores. Alteration in the structure of collagen due to chronic ultraviolet radiation (UVR) exposure may influence the intensity of the autofluorescence. The aim of this study was to investigate the relation between collagen‐linked autofluorescence and sun exposure to clarify whether the skin can be used as a biological UVR dosimeter.

Ultraviolet radiation exposure pattern in winter compared with summer based on time-stamped personal dosimeter readings

Background  Personal annual ultraviolet (UV) radiation data based on daily records are needed to develop protective strategies.

Compliance and data reliability in sun exposure studies with diaries and personal, electronic UV dosimeters

Background/purpose: Skin cancer risk estimations are based on sun exposure data. However, the reliability of collected data in personal ultraviolet (UV) dosimeters studies has not previously been validated. We aimed at investigating the data reliability and subject compliance in a study of sun exposure behaviour among 407 subjects (age range, 4–68 years) during 54 943 days based on time‐stamped personal UV dosimeter readings and diary records.

Determinants of personal ultraviolet-radiation exposure doses on a sun holiday

Background  A great number of journeys to sunny destinations are sold to the Danish population every year. We suspect that this travel considerably increases personal annual ultraviolet‐radiation (UVR) exposure doses. This is important because such exposure is the main cause of skin cancer, and studies have shown a correlation between intermittent solar UVR exposure and malignant melanoma.

A sun holiday is a sunburn holiday

Many people take holidays in sunny locations with the express aim of sunbathing. This may result in sunburn, which is a risk factor for skin cancer. We investigated 25 Danish sun seekers during a weeks holiday in the Canary Islands. The percentage of body surface area with sunburn was determined by daily skin examinations by the same observer. Erythemally effective ultraviolet radiation (UVR) exposure was assessed with time‐stamped personal dosimeters worn on the wrist. Volunteers reported their clothing cover and sunscreen use in diaries, and this information was used to determine body site‐specific UVR doses after adjustment for sun protection factor. Remarkably, we found that all volunteers sunburned at some point. The risk of sunburn correlated significantly with the adjusted body site‐specific UVR dose. Furthermore, there was also a significant relationship between the daily UVR dose and percentage of body surface area with sunburn. Our study shows that holiday UVR exposure results in a high risk of sunburn, which potentially increases the risk of skin cancer. Possible protection by melanogenesis is insufficient to protect against sunburn during a 1‐week sun holiday. Finally, our data clearly support a substantial skin cancer risk from sun holidays.