Solar UVR exposure, concurrent activities and sun-protective practices among primary schoolchildren

Comprehensive measures of ultraviolet radiation (UVR) exposure, concurrent activities and sun-protective practices are needed to develop and evaluate skin cancer prevention and sun protection interventions. The UVR exposures of 345 primary schoolchildren at 23 schools around New Zealand were measured using electronic UVR monitors for 1-week periods over 12 weeks in 2004 and 2005. In addition, ambient UVR levels on a horizontal surface were measured on-site at each school. Children completed activity diaries during the period UVR measurements were made and provided information on their indoor and outdoor status and clothing and sun protection worn. Mean total daily UVR exposure (7:00-20:00 h NZST + 1) at the body location where the UVR monitors were worn was 0.9 SED (standard erythemal dose, 1 SED = 100 J m(-2)). This was 4.9% of the ambient UVR on a horizontal surface. Mean time spent outdoors was 2.3 h day(-1). Differences in children's UVR exposure could be explained in part by activity, where outdoor passive pursuits were associated with higher UVR exposure rates than outdoor active and outdoor travel pursuits. Compared with older children, the activities of younger children, although labeled the same, resulted in different UVR exposures, either as a result of reporting differences or a real difference in UVR exposure patterns. UVR exposure rates were generally higher on weekdays compared with the weekend, confirming the important role of school sun protection and skin cancer prevention programs. High UVR exposure activities included physical education, athletics and lunch break.     

Simplified categorization of outdoor activities for male and female U.S. indoor workers-a feasibility study to improve assessment of ultraviolet radiation exposures in epidemiologic study questionnaires

Skin cancer studies depend on questionnaires to estimate exposure to ultraviolet light and subsequent risk but are limited by recall bias. We investigate the feasibility of developing a short checklist of categories comprising outdoor activities that can improve sun exposure questionnaires for use in epidemiologic studies. We recruited 124 working and retired U.S. radiologic technologists (52% women). Each subject was instructed to complete a daily activity diary, listing main indoor and outdoor activities between 9:00 A.M. and 5:00 P.M. during a 7 day period. A total of 4697 entries were associated with 1408 h (21.1%) of the total 6944 h spent outdoors. We were able to classify the activities into seven main activity categories: driving, yard work, home-maintenance, walking or performing errands, water activities, other recreational or sports activities and leisure activities or relaxing outside. These activities accounted for more than 94% of time spent outdoors both for working and retired men and women. Our data document the feasibility and guidance for developing a short checklist of outdoor activities for use in epidemiologic questionnaires for estimating sunlight exposures of working and retired indoor workers.     

Seasonal Minimum and Maximum Solar Ultraviolet Exposure Measurements of Classroom Teachers Residing in Tropical North Queensland,Australia

The risk of keratinocyte skin cancer, malignant melanoma and ultraviolet radiation (UVR)‐induced eye disease is disproportionately higher in Australia and New Zealand compared to equivalent northern hemisphere latitudes. While many teachers are aware of the importance of reinforcing sun safety messages to students, many may not be aware of the considerable personal exposure risk while performing outdoor duties in locations experiencing high to extreme ambient UVR year‐round. Personal erythemally effective exposure of classroom teachers in tropical Townsville (19.3°S) was measured to establish seasonal extremes in exposure behavior. Mean daily personal exposure was higher in winter (91.2 J m^‐2, 0.91 Standard Erythema Dose [SED]) than summer (63.3 J m^?2, 0.63 SED). The range of exposures represents personal exposures that approximate current national guidelines for Australian workers at the study latitude of approximately 1.2 SED (30 J m^?2 effective to the International Commission on Non‐Ionizing Radiation Protection). Similar proportions of teachers spent more than 1 h outdoors per day in winter (28.6%) and summer (23.6%) as part of their teaching duties with seasonal differences having little effect on the time of exposure. Personal exposures for teachers peaked during both seasons near school meal break times at 11:00 am and 1:00 pm, respectively.     

Validation of Sun Exposure Reported Annually Against Interim Self‐report and Daily Sun Diaries

Data on personal sun exposure over a period exceeding the immediate past days or weeks are typically self‐reported in brief questionnaire items. The validity of such self‐reporting of longer term personal sun exposure, for example over a year, including detail on variation across seasons, has not previously been investigated. In a volunteer sample (n = 331) of Australian adults aged 18 years and over, we assessed the 12‐month reliability of sun exposure reported separately for each season, and its accuracy compared to a daily sun diary in the same season. Seasonal time outdoors displayed fair‐to‐good reliability between baseline and end of study (12 months), with responses showing higher agreement at lower levels of time outdoors. There was good agreement for ranking of individuals' time outdoors with the daily sun diary data, although the actual diary time outdoors was typically considerably lower than the self‐reported questionnaire data. Place of residence, education, being a smoker, day of the week (i.e. working day vs nonworking day) and working mainly outdoors were significant predictors of agreement. While participants overestimated their actual time outdoors, the self‐report questionnaire provided a valid ranking of long‐term sun exposure against others in the study that was reliable over time.     

Sun Exposure at School

There is strong evidence that sun exposure during childhood and adolescence plays an important role in the etiology of skin cancer, in particular cutaneous melanoma. Between the age of 6 and 18, most children and adolescents will spend around 200 days per year at school and may receive a substantial fraction of their daily total solar ultraviolet radiation (UVR) exposure while at school. This study estimated the average daily erythemally effective dose of 70 grade 8 students from a high school in Townsville during 5 school days in July 1998. Through UV measurements of shade locations at the school and a combination of frequency counts and a questionnaire of grade 8 students, it was possible to determine the fraction of solar UVR reaching under the shade structures during lunch breaks and routine outdoor activities. Also, a routinely operating UV-Biometer provided the annual variation of the daily dose that was used to calculate exposure levels for the 70 students. Our results suggest that up to 47% of the daily total dose fell within the time periods where students were outdoors during school hours. For students not seeking shade structures during the breaks (which usually was the case when involved in sport activities such as basketball or soccer), the average daily dose could have been as high as 14 SED (standard erythemal dose). Using results from the questionnaire of 70 grade 8 students, their average annual dose while at school was 414 SED or 2 SED per school day. However, the distribution of average daily erythemal effective dose per grade 8 student over the whole year showed that on 31% of all school days in 1998, this dose was exceeded. Because most previous attempts to change arguably poor sun-protective behavior of young Australian children and adolescents at school showed little success, one way of decreasing the amount of harmful UVR reaching unprotected skin is the more careful design of shade structures at schools.     

Solar Ultraviolet Radiation Exposure and Sun Protection Behaviors and Knowledge Among a High‐Risk and Overlooked Group of Outdoor Workers in South Africa

The exposure of outdoor car guards to solar ultraviolet radiation (UVR), the majority with deeply pigmented skin, to solar UVR was measured for five consecutive days during early spring (September 2017) in South Africa using electronic UVR dosimeters attached to the upper arm of each participant. The exposure of the nape of the neck, forehead, nose, cheek and hand was extrapolated from the measurements. The onsite ambient solar UVR on a flat, horizontal, unshaded surface was measured concurrently. The sun‐related knowledge, behavior and attitudes of the car guards were evaluated using questionnaires. Total personal daily solar UVR exposure as a percentage of the ambient solar UVR exposure was 24%. The exposure of car guards on several body sites was in excess of the occupational threshold limit value. Sleeved shirts and hats were the most commonly used sun protection measures (worn by 70% and 80%, respectively). Considering the high levels of solar UVR reported on most days throughout the year in South Africa, more studies quantifying the personal exposure of outdoor workers in both the informal and formal sectors are necessary.     

Seasonal Variation in Measured Solar Ultraviolet Radiation Exposure of Adults in Subtropical Australia

Generating accurate population-specific public health messages regarding sun protection requires knowledge about seasonal variation in sun exposure in different environments. To address this issue for a subtropical area of Australia, we used polysulphone badges to measure UVR for the township of Nambour (26° latitude) and personal UVR exposure among Nambour residents who were taking part in a skin cancer prevention trial. Badges were worn by participants for two winter and two summer days. The ambient UVR was approximately three times as high in summer as in winter. However, participants received more than twice the proportion of available UVR in winter as in summer (6.5%vs 2.7%, P < 0.05), resulting in an average ratio of summer to winter personal UVR exposure of 1.35. The average absolute difference in daily dose between summer and winter was only one-seventh of a minimal erythemal dose. Extrapolating from our data, we estimate that ca. 42% of the total exposure received in the 6 months of winter (June–August) and summer (December–February) is received during the three winter months. Our data show that in Queensland a substantial proportion of people’s annual UVR dose is obtained in winter, underscoring the need for dissemination of sun protection messages throughout the year in subtropical and tropical climates.     

Ultraviolet radiation exposure of children and adolescents in Durban,South Africa

The solar ultraviolet radiation (UVR) exposure of 30 children and adolescents in three age groups (4-6 years, 7-9 years and 13-14 years) was measured for 1 week in late summer (February-March) in Durban, South Africa, using UVR-sensitive polysulfone film badges (PSFB) attached to the lapel region of the body. The mean and median values for all ages over the study period were 2.0 and 1.2 standard erythemal dose (SED) units, respectively, where 1 SED = 100 J x m(-2). Individual PSFB doses were analyzed as a function of age, gender and behavior. No significant statistical differences were found between different age groups; however, there was a statistical difference between males and females, with males generally receiving higher PSFB doses. Subjects completed UVR exposure journals documenting their time outdoors, shade versus sun conditions, nature of their activities, clothing worn and their use of sunscreen for each day of the study. Activity patterns were noted as the most important factor influencing individual UVR dose. Ambient erythemal UVR was measured by a Yankee Environmental Systems UVB pyranometer, and a relationship between ambient UVR and individual UVR dose was derived. On average, subjects received a dose of 4.6% of the total daily erythemal UVR. Based on this factor, the potential dose of an individual over a full annual cycle was estimated. Accordingly, there were 139 days during the year when an individual with skin type I (light skin) would be likely to experience minimal erythema and 97 and 32 days for individuals with skin types II and III, respectively.     

Validation of Brief Questionnaire Measures of Sun Exposure and Skin Pigmentation Against Detailed and Objective Measures Including Vitamin D Status

Self‐reported sun exposure is commonly used in research, but how well this represents actual sun exposure is poorly understood. From February to July 2011, a volunteer sample (n = 47) of older adults (≥45 years) in Canberra, Australia, answered brief questions on time outdoors (weekdays and weekends) and natural skin color. They subsequently maintained a sun diary and wore an ultraviolet radiation (UVR) digital dosimeter for 7 days. Melanin density was estimated using reflectance spectrophotometry; lifetime sun damage was assessed using silicone casts of the back of the hand; and serum 25‐hydroxyvitamin D (25(OH)D) concentration was assayed. Questionnaire‐reported time outdoors correlated significantly with diary‐recorded time outdoors (Spearman correlation r_s = 0.66; 95% CI 0.46, 0.80; P < 0.001) and UVR dosimeter dose (r_s = 0.46; 95% CI 0.18, 0.68; P = 0.003), but not 25(OH)D concentration (r_s = 0.24; 95% CI ?0.05, 0.50; P = 0.10). Questionnaire‐reported untanned skin color correlated significantly with measured melanin density at the inner upper arm (r_s = 0.49; 95% CI 0.24, 0.68; P < 0.001). In a multiple linear regression model, statistically significant predictors of 25(OH)D concentration were self‐reported frequency of physical activity, skin color and recent osteoporosis treatment (R² = 0.54). In this study, brief questionnaire items provided valid rankings of sun exposure and skin color, and enabled the development of a predictive model for 25(OH)D concentration.     

A Comparison of Solar Ultraviolet Radiation Exposure in Urban Canyons in Venice,Italy and Johannesburg,South Africa

Urban environments can have high-risk spaces that can provide excess personal sun exposure, such as urban or street canyons, and the spaces between buildings, among others. In these urban spaces, sun exposure can be high or low depending on several factors. Polysulphone film (PSF) was used to assess possible daily solar ultraviolet radiation (UVR) exposure in urban canyons in Venice, Italy and, for the first time in Africa, in Johannesburg, South Africa. The photodegradation of PSF upon solar exposure was monitored at a wavelength of 330 nm by ultraviolet-visible spectrophotometry, and the resultant change was converted to standard erythemal dose (SED) units (1 SED = 100 J m⁻²). Mean daily ambient solar UVR exposure measured for Venice and Johannesburg ranged between 20–28 SED and 33–43 SED, respectively. Canyon-located PSF exposures were lower in Venice (1–9 SED) than those in Johannesburg (9–39 SED), depending mainly on the sky view factor and orientation to the sun. There was large variation in solar UVR exposure levels in different urban canyons. These preliminary results should be bolstered with additional studies for a better understanding of excess personal exposure risk in urban areas, especially in Africa.     

Correlation between Objective Measures of Sun Exposure and Self-Reported Sun Protective Behavior and Attitudes in Predominantly Hispanic Youth

Melanoma incidence is increasing, with poor prognosis cases growing faster in California Hispanics than in non-Hispanic whites. Ultraviolet Radiation (UVR) exposure as a child has been found to disproportionately increase the risk of melanoma. To determine correlates of UVR exposure in this high-risk population, we conducted a study in predominately Hispanic 4th and 5th grade classrooms in Los Angeles County, a high UVR environment, during the spring. To address potential reporting bias, electronic UV dosimeters were utilized to objectively measure the association between UVR exposure and constructs (acculturation, sun protective behavior and knowledge, family interventions) obtained on baseline questionnaires (n = 125). Tanning attitude (wanting to get a tan) was associated with lower median time spent outside (1.73 min versus 22.17, AUC 82.08, Sensitivity 0.78, Specificity 0.73) and standard erythemal dose (SED) on weekends, but positively associated with sun protective knowledge. Sun protective knowledge and family discussion of sunscreen were also inversely associated with objectively measured time outside. Students spent a median 30.61 (IQR 19.88) minutes outside per day (SED 0.30, IQR 0.20), with only 35.70% of it occurring in nonschool hours. We determined the majority of UVR exposure in this population occurs at school, providing valuable guidance for future interventions.     

UV Radiation Exposure of Outdoor Workers in Antarctica

The Antarctic region is a place of increasing interest. A growing number of personnel are working outdoors in extreme environmental conditions. They receive significant exposure to solar ultraviolet radiation (UVR) and are thereby at increased risk of adverse consequences. The aim of this study was to evaluate the UVR dose received by the outdoor workers at the Bulgarian Antarctic Base. Ten Caucasian healthy subjects, 8 males and 2 females with a mean age of 38 years (29–51) were enrolled. Of them, 5 were scientists and 5 were logistic workers. We measured the accumulated daily dose of UVR assessed by standard erythemal dose (SED) in the two groups. All subjects wore personal dosimeters located near the face—he only noncovered skin area. The dosimeters were factory calibrated for use in the Antarctic region. No statistical difference (P = 0.441) could be revealed between the SEDs in the two groups. The maximum UVR dose detected in a single day was 67.9 SEDs, and the highest cumulative dose was 548.03 SEDs. Study results are showing extreme measurements of UVR received by the members of the expeditions. We suggest meticulous UV protection for outdoor workers.     

A pilot study of the validity of self-reported ultraviolet radiation exposure and sun protection practices among lifeguards, parents and children

Outdoor recreation settings, such as swimming pools, provide a promising venue to assess UVR exposure and sun protection practices among individuals who are minimally clothed and exposed to potentially high levels of UVR. Most studies assessing sun exposure/protection practices rely on self-reported data, which are subject to bias. The aim of this study was to establish the feasibility of conducting a multimethod study to examine the validity of self-reported measures within a swimming pool setting. Data were collected from 27 lifeguards, children and parents in Hawaii. Each participant filled out a survey and a 4 day sun habits diary. On two occasions, researchers assessed observable sun protection behaviors (wearing hats, shirts, sunglasses), swabbed the skin to detect the presence of sunscreen, and subjects wore polysulphone dosimeters to measure UVR exposure. Overall, observed sun protection behaviors were more highly correlated with diary reports than with survey reports. While lifeguards and children reported spending comparable amounts of time in the sun, dosimeter measures showed that lifeguards received twice as much UVR exposure. This study demonstrated the feasibility of implementing a multimethod validity study within a broader population of swimming pools.     

Changes in Time Spent Outdoors During the Daytime in Rural Populations in Four Geographically Distinct Regions in China: A Retrospective Study

Changes in time‐activity patterns may influence personal exposure to various environmental factors and affect individual health. However, few studies have investigated the changes in patterns of time spent outdoors. To investigate the trends in outdoor activity in recent decades in China, a retrospective questionnaire was used to examine the amount and pattern of time spent outdoors during the day by 2076 subjects in four geographically distinct rural regions of China. Rural Chinese people spent less time outdoors than they used to because of the economic development, increase in education and changes in working conditions that occurred over time. Outdoor time was the shortest during the school stage of life (Sanya: 3.24–3.61; Shaoxing: 3.35–3.68; Lhasa: 4.37–4.54; Xiuyan: 2.94–3.26 h per day). Subjects in wealthy regions spent less time outdoors during their working stage of life. In the four regions in this study, the average daily times spent outdoors were 3–13% lower for subjects aged 40–59 years and 20–38% lower for those under 40 years compared to subjects aged 60 years and over. Certain health‐related issues, such as vitamin D deficiency, will become more prominent in China if this trend continues.     

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.     

Significant Associations Between Sun Exposure and Adiposity Were Not Observed in Breast and Prostate Cancer Patients in a Cross‐sectional Analysis

Obesity is a significant health problem worldwide. Exposure to low‐dose ultraviolet radiation (like that in sunlight) suppresses the development of obesity in mice; however, the nature of the associations between sun exposure and adiposity is not well understood in humans. The present study characterized cross‐sectional relationships between sun exposure and adiposity in a convenience cohort of breast (n = 269; mean age = 58 years) and prostate (n = 78; mean age = 69 years) cancer patients. Participants were enrolled in a 3‐month exercise program in Perth, Australia. Self‐reported questionnaires measured time spent outdoors (previous week, winter and summer), sex, age, treatment received and physical activity levels. Adiposity measures included body mass index, waist‐hip ratio and body fat percentage (measured via DXA). In unadjusted models, greater time spent outdoors across all times was significantly associated with lower waist‐hip ratio, while greater time spent outdoors in the last winter was associated with lower body fat percentage, but not when stratified by sex. There were no statistically significant associations between time spent outdoors and adiposity after adjusting for sex, age, treatments received and physical activity. Longitudinal studies in larger populations may elucidate significant associations not found in our study due to the cross‐sectional design and power limitations.     

PERSONAL DOSIMETRY OF SOLAR UV RADIATION FOR DIFFERENT OUTDOOR ACTIVITIES

Abstract 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.     

Solar UVR Exposures of Primary School Children at Three Locations in Queensland

Abstract— The ultraviolet radiation (UVR) exposures of primary school children in Brisbane, Toowoomba and Mackay (latitudes 27°30', 27°33' and 21°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.     

Occupational UV Exposure of Environmental Agents in Valencia,Spain

Excessive exposure to ultraviolet radiation (UVR) is considered the most important environmental risk factor in the development of melanoma and skin cancer. Outdoor workers are among those with the highest risk from exposure to solar UVR, as their daily activities constantly expose them to this radiation source. A study was carried out in Valencia, Spain, in summer 2012 and involved a group of 11 workers for a period of six 2‐day recordings. Sensitive spore‐film filter‐type personal dosimeters (VioSpor) were used to measure erythemal UVR received by environmental agents in the course of their daily work. Median 2‐day UV exposure was 6.2 standard erythema dose (SED), with 1 SED defined as effective 100 J m^?2 when weighted with the Commission Internationale de L′Eclairage's (CIE) erythemal response function. These workers were found to receive a median of 8.3% total daily ambient ultraviolet erythemal radiation. Comparison with the occupational UV exposure limit showed that the subjects had received an erythemal UV dose in excess of occupational guidelines, indicating that protective measures against this risk are highly advisable.     

Method for Measurements of Terrestrial Ultraviolet Radiation on Inclined Surfaces in Personal Dosimetry Field Studies

Understanding personal ultraviolet radiation (UVR) exposure is essential for the evaluation of the health risks and benefits; however, personal dosimetry could be challenging in large‐scale or/and long‐term population studies. Alternatively, personal exposure could be simulated using three‐dimensional models and lifestyle surveys together with data on a body position with respect to the sun. These models require a real‐time input on local environmental UVR. The main challenge in using this method is retrieval of the diffuse irradiance as it requires an often‐expensive tracking of solar position. In this study, a hypothesis that UVR measured on a vertical plane in the north direction can be used in the UK as a proxy for diffuse radiation was tested against direct measurements and compared with models based on solar tracker data in Chilton, UK, (51.57°N) in June–July 2018. The statistical analysis over 17 days under all weather conditions showed that for 45° and 90° tilted surfaces the proposed method performed as well as the best of the models based on solar tracker data. A proposed system could offer a portable and low‐cost alternative to measurements of diffuse radiation by solar tracking radiometers for spatial distribution of terrestrial erythema effective UVR in population field studies.