Agreement between diary records of time spent outdoors and personal ultraviolet radiation dose measurements

Adherence with statins and all-cause mortality in days with high temperature

PURPOSE

It has been suggested that statins may exert thermo-protective effects that can reduce mortality on hot days. We aimed to examine the relationship between statin adherence and mortality in days with high temperature.

METHODS

Utilizing data from a prior historical new-user cohort study, we analyzed a cohort of 229 918 individuals within a state-mandated health provider in Israel who initiated statin therapy between 1998 and 2006. Adherence to statins was assessed through the mean proportion of days covered (PDC) with statins during the follow-up period. The study's primary outcome was all-cause mortality during hot days.

RESULTS

During the study follow-up period, a total of 13 165 individuals (5.7%) died. In a multivariable model, a 10% increase in PDC with statins was associated with an HR of (0.85; 95% CI: 0.72-1.00) for deaths (n = 16) in extremely hot days (≥39°C). This association was numerically stronger compared to HR = 0.94 (0.93-0.94) in cooler days and displayed a significant difference between sexes. In males, the fully-adjusted HR for a 10% increase in PDC with statins was 0.66 (0.45-0.95), while in women, it was 0.98 (0.78-1.23). In contrast, no such effect modification was observed for death in cooler days.

CONCLUSIONS

These findings align with earlier research, supporting the notion that adherence with statin treatment may be associated with a reduced risk of death during extremely hot days, particularly among men.

Weather-Related Human Outdoor Behavior with Respect to Solar Ultraviolet Radiation Exposure in a Changing Climate

Climate-related changes in human sun exposure behavior can be an important influence on future ultraviolet radiation (UVR) related disease risks. In particular, active leisure mobility and leisure activities are more dependent on weather conditions than routine activities. However, the direction and extent of the effects vary. For temperate and cold climates, the available studies provide indications that a possible increase in UVR exposure would primarily result from a reduction in clothing and only secondarily from changes in the time spent outdoors. Existing studies suggest a nonlinear, bell-shaped relationship with threshold value effects for the relationship between outdoor time and thermal conditions. If the local climate is already very warm and there are only minor seasonal differences, there is no statistically significant evidence of changes in behavior. If there is significant warm discomfort, there is a tendency to avoid being outdoors or in the sun. It is not justified to simply transfer and generalize results and conclusions to different climates and seasons and between different leisure activities and forms of active mobility. The geographical context must be considered also in terms of cultures and habits, adaptations, traffic and land use (urban, rural). In addition, changes in behavior can develop differently depending on individual characteristics of people such as heat affinity, leisure type, age and gender. Differentiated analyses are required that take into account and balance opposing effects.

Estimating personal solar ultraviolet radiation exposure through time spent outdoors, ambient levels and modelling approaches

BACKGROUND

 Evidence on validation of surrogates applied to evaluate the personal exposure levels of solar ultraviolet radiation (UVR) in epidemiological studies is scarce.

OBJECTIVES

 To determine and compare the validity of three approaches, including (i) ambient UVR levels, (ii) time spent outdoors, and (iii) a modelling approach integrating the aforementioned parameters, to estimate personal UVR exposure over a period of six months among indoor and outdoor workers and in different seasons (summer/winter).

METHODS

 This validation study was part of the EU ICEPURE project and was performed between July 2010 and January 2011 in a convenience sample of indoor and outdoor workers in Catalunya - Spain. We developed linear regression models to quantify the variation in the objectively measured personal UVR exposure that could be explained, separately, by the ambient UVR, time spent outdoors, and modelled UVR levels.

RESULTS

Our 39 participants - mostly male and with a median age of 35 years- presented a median daily objectively measured UVR of 0.37 standard erythemal doses (SEDs). The UVR dose was statistically significantly higher in summer and for outdoor workers. The modelled personal UVR exposure and self-reported time spent outdoors could reasonably predict the variation in the objectively measured personal UVR levels (R² = (0.75, 0.79)), whereas ambient UVR was a poor predictor (R² =0.21). No notable differences were found between seasons or occupation.

CONCLUSIONS

 Time outdoors and our modelling approach were reliable predictors and of value to be applied in epidemiological studies of the health effects of current exposure to UVR.

Time spent outdoors in childhood is associated with reduced risk of myopia as an adult

Myopia (near-sightedness) is an important public health issue. Spending more time outdoors can prevent myopia but the long-term association between this exposure and myopia has not been well characterised. We investigated the relationship between time spent outdoors in childhood, adolescence and young adulthood and risk of myopia in young adulthood. The Kidskin Young Adult Myopia Study (KYAMS) was a follow-up of the Kidskin Study, a sun exposure-intervention study of 1776 children aged 6–12 years. Myopia status was assessed in 303 (17.6%) KYAMS participants (aged 25–30 years) and several subjective and objective measures of time spent outdoors were collected in childhood (8–12 years) and adulthood. Index measures of total, childhood and recent time spent outdoors were developed using confirmatory factor analysis. Logistic regression was used to assess the association between a 0.1-unit change in the time outdoor indices and risk of myopia after adjusting for sex, education, outdoor occupation, parental myopia, parental education, ancestry and Kidskin Study intervention group. Spending more time outdoors during childhood was associated with reduced risk of myopia in young adulthood (multivariable odds ratio [OR] 0.82, 95% confidence interval [CI] 0.69, 0.98). Spending more time outdoors in later adolescence and young adulthood was associated with reduced risk of late-onset myopia (≥ 15 years of age, multivariable OR 0.79, 95% CI 0.64, 0.98). Spending more time outdoors in both childhood and adolescence was associated with less myopia in young adulthood.

Recalling our day in the sun: comparing long-term recall of childhood sun exposure with prospectively collected parent-reported data

To examine the impact of sun exposure on human health, accurate measures of past sun exposure are required. We investigated how young adults' recall of childhood sun-related behaviours compares with parent-reported measures collected during childhood. The Kidskin-Young Adult Myopia Study (KYAMS) is a follow-up of the Kidskin Study, a sun-protection intervention study conducted from 1995-2001. KYAMS participants, aged 25-30 years, reported time in sun, and use of hats and sunscreen, for each year from ages 5-26 years (n = 244). Using weighted kappa, we assessed agreement between these data and corresponding variables derived from the Kidskin Study parent questionnaires completed when KYAMS participants were aged 6-12 years. Ordinal logistic regression was used to test the association between self-reported sun-behaviours and corresponding parent-reported data. We found slight agreement between self-reported and parent-reported data for all sun-behaviour measures except hat use at 12 years. KYAMS recall of time in sun at 8-12 years was not associated with Kidskin Study parent-reported responses after adjustment for current time in sun. Recall of higher hat and sunscreen use was associated with higher parent-reported hat and sunscreen use (OR[hat] = 1.37, 95% CI: 1.16, 1.62; OR[sunscreen] = 1.23, 95% CI: 1.03, 1.48). However, KYAMS self-reported data were unable to predict corresponding parent-reported responses. Group data from retrospective recall of sun-related behaviours may be of limited value in studying the relationship between sun exposure and health outcomes; however, individual data are likely of little use.

Shade coverage, ultraviolet radiation and children's physical activity in early childhood education and care

OBJECTIVE

To investigate the association between shade coverage in early childhood education and care (ECEC) centres and pre-school children's physical activity, outdoor time and ultraviolet radiation (UVR) exposure.

METHODS

A total of 48 ECEC centres (678 children) in the Western Australian Play Spaces and Environments for Children's Physical Activity (PLAYCE) study took part. Physical activity at ECEC was measured using 7-day accelerometry. UVR exposure was measured using polysulphone film attached to children's shoulders. Educators reported time spent outdoors. The Shade Factor and remote sensing imagery captured shade coverage.

RESULTS

Centre vegetation but not Shade Factor was significantly negatively associated with children's UVR exposure (p < 0.001). Higher levels of vegetation were associated with increased time outdoors, but higher levels of the Shade Factor were associated with decreased time outdoors (all p < 0.001). Neither shade measure was significantly associated with physical activity. Outdoor time moderated the relationships between shade measures, physical activity and UVR exposure.

CONCLUSIONS

The provision of shade, particularly through natural forms such as tree canopy, is an important sun protection strategy and enabler of outdoor time in children attending ECEC.

Daily Minutes of Unprotected Sun Exposure (MUSE) Inventory: Measure description and comparisons to UVR sensor and sun protection survey data

One in five US adults will be diagnosed with skin cancer. As most skin cancers are attributable to sun exposure, this risk factor is an important target for research and intervention. Most sun exposure measures assess frequency of specific sun-protection behaviors, which does not account for the use of multiple, potentially overlapping sun-protection methods. In contrast, the Daily Minutes of Unprotected Sun Exposure (MUSE) Inventory assesses sun-protection behavior during self-reported activities, providing several useful metrics, including duration of unprotected sun exposure on 17 body sites, combined to yield an overall MUSE score weighted by percent of body exposed. The present study was conducted July–September 2017, in Chicago, IL USA. For 10 days, participants (39 melanoma survivors; M_age = 58.59, 64.5% female) wore an ultraviolet radiation (UVR) sensor and completed the Daily MUSE Inventory each evening. The Sun Habits Survey was completed at the end of the study. Outdoor time reported in the MUSE Inventory significantly predicted outdoor time recorded by UVR sensors, B = 0.53, p < .001. For all sun-protection behaviors except shade, reports from the Daily MUSE Inventory (i.e., percentage of outdoor time a particular strategy was used) correlated with frequency ratings of the same strategy from the Sun Habits Survey (rs = 0.66–0.75, p < .05). In sum, the Daily MUSE Inventory corresponds with sensor and survey data, and provides a novel metric of unprotected sun exposure that will be useful for evaluating overall extent of sun exposure, including exposure on several smaller body sites that are at high risk for skin cancer.

The measurement of time spent outdoors in child myopia research: a systematic review

The purpose of this article is to summarize the methods most commonly used to measure time spent outdoors and provide a comprehensive review of time and activity recording methods with the aim of encouraging the development of new methods. PubMed, Embase and the Cochrane Library were searched from Jan. 1^st, 1990 to Aug. 31^th, 2017. Studies including the following specific terms: "outdoor", "outside", "outdoor activity", "outside activity", "outdoor time", "outside time", and "outdoor AND measurement of time spent outdoors" were considered for this review. In total, three kinds of outdoor time measurements were discussed. Questionnaires have the longest history and are the most thoroughly revised instruments for assessing time spent outdoors, but recall bias is their most substantial drawback. Global positioning system (GPS) tracking can distinguish between indoor and outdoor locations, but its utility is limited due to several factors such as subject compatibility. Light exposure measurement devices are newly emerging, but all of these devices require good subject cooperation. Further efforts and exploration are needed to develop better methods and new tools to record exposure to the outdoors in real time. Moreover, inventing a new device by combining two or more types of devices mentioned above and using the latest technology of en ergy supplementation and autoswitching may make the best use of the advantages and bypass the disadvantages of each tool.

Review on Nonoccupational Personal Solar UV Exposure Measurements

Solar ultraviolet (UV) radiation follows people during their whole life. Exposure to UV radiation is vital but holds serious risks, too. The quantification of human UV exposure is a complex issue. UV exposure is directly related to incoming UV radiation as well as to a variety of factors such as the orientation of the exposed anatomical site with respect to the sun and the duration of exposure. The use of badge-sensors allows assessing the UV exposure of differently oriented body sites. Such UV devices have been available for over 40 years, and a variety of measuring campaigns have been undertaken since then. This study provides an overview of those studies which reported measurements of the personal UV exposure (PE) during outdoor activities of people not related to their occupation. This overview is given chronologically to show the progress of knowledge in this research and is given with respect to different activities. Special focus is put on the ratio of personal exposure to ambient UV radiation. This ratio, when given as a function of solar elevation, allows estimating PE at any other location or date if ambient UV radiation is known.

Capturing Ultraviolet Radiation Exposure and Physical Activity: Feasibility Study and Comparison Between Self-Reports, Mobile Apps, Dosimeters, and Accelerometers

Background

Skin cancer is the most prevalent cancer in Australia. Skin cancer prevention programs aim to reduce sun exposure and increase sun protection behaviors. Effectiveness is usually assessed through self-report.

Objective

It was the aim of this study to test the acceptance and validity of a newly developed ultraviolet radiation (UVR) exposure app, designed to reduce the data collection burden to research participants. Physical activity data was collected because a strong focus on sun avoidance may result in unhealthy reductions in physical activity. This paper provides lessons learned from collecting data from participants using paper diaries, a mobile app, dosimeters, and accelerometers for measuring end-points of UVR exposure and physical activity.

Methods

Two participant groups were recruited through social and traditional media campaigns 1) Group A—UVR Diaries and 2) Group B—Physical Activity. In Group A, nineteen participants wore an UVR dosimeter wristwatch (University of Canterbury, New Zealand) when outside for 7 days. They also recorded their sun exposure and physical activity levels using both 1) the UVR diary app and 2) a paper UVR diary. In Group B, 55 participants wore an accelerometer (Actigraph, Pensacola, FL, USA) for 14 days and completed the UVR diary app. Data from the UVR diary app were compared with UVR dosimeter wristwatch, accelerometer, and paper UVR diary data. Cohen kappa coefficient score was used to determine if there was agreement between categorical variables for different UVR data collection methods and Spearman rank correlation coefficient was used to determine agreement between continuous accelerometer data and app-collected self-report physical activity.

Results

The mean age of participants in Groups A (n=19) and B (n=55) was 29.3 and 25.4 years, and 63% (12/19) and 75% (41/55) were females, respectively. Self-reported sun exposure data in the UVR app correlated highly with UVR dosimetry (κ=0.83, 95% CI 0.64-1.00, P<.001). Correlation between self-reported UVR app and accelerometer-collected moderate to vigorous physical activity data was low (ρ=0.23, P=.10), while agreement for low-intensity physical activity was significantly different (ρ=-0.49, P<.001). Seventy-nine percent of participants preferred the app over the paper diary for daily self-report of UVR exposure and physical activity.

Conclusions

This feasibility study highlights self-report using an UVR app can reliably collect personal UVR exposure, but further improvements are required before the app can also be used to collect physical activity data.

A Pilot Randomized Controlled Trial of the Feasibility, Acceptability, and Impact of Giving Information on Personalized Genomic Risk of Melanoma to the Public

BACKGROUND

Communication of personalized melanoma genomic risk information may improve melanoma prevention behaviors.

METHODS

We evaluated the feasibility and acceptability of communicating personalized genomic risk of melanoma to the public and its preliminary impact on behaviors and psychosocial outcomes. One hundred eighteen people aged 22 to 69 years provided a saliva sample and were randomized to the control (nonpersonalized educational materials) or intervention (personalized booklet presenting melanoma genomic risk as absolute and relative risks and a risk category based on variants in 21 genes, telephone-based genetic counseling, and nonpersonalized educational materials). Intention-to-treat analyses overall and by-risk category were conducted using ANCOVA adjusted for baseline values.

RESULTS

Consent to participate was 41%, 99% were successfully genotyped, and 92% completed 3-month follow-up. Intervention participants reported high satisfaction with the personalized booklet (mean = 8.6, SD = 1.6; on a 0-10 scale) and genetic counseling (mean = 8.1, SD = 2.2). No significant behavioral effects at 3-month follow-up were identified between intervention and control groups overall: objectively measured standard erythemal doses per day [-16%; 95% confidence interval (CI), -43% to 24%] and sun protection index (0.05; 95% CI, -0.07 to 0.18). There was increased confidence identifying melanoma at 3 months (0.40; 95% CI, 0.10-0.69). Stratified by risk category, effect sizes for intentional tanning and some individual sun protection items appeared stronger for the average-risk group. There were no appreciable group differences in skin cancer-related worry or psychologic distress.

CONCLUSIONS

Our results demonstrate feasibility and acceptability of providing personalized genomic risk of melanoma to the public.

IMPACT

Genomic risk information has potential as a melanoma prevention strategy. Cancer Epidemiol Biomarkers Prev; 26(2); 212-21. ©2016 AACR.

Ultraviolet radiation and systemic lupus erythematosus

Exposure to ultraviolet (UV) radiation is among the environmental factors that have been proposed and studied in association with systemic lupus erythematosus (SLE). While it is known that UV radiation exposure may exacerbate pre-existing lupus, it remains unclear whether UV exposure is a risk factor for the development of SLE. Experimental studies show a significant immunomodulatory role for UV radiation, but strong epidemiologic data regarding its role in triggering SLE onset are lacking. Further studies are needed to assess the role of UV radiation in relation to development of incident SLE, yet they are challenging to design due to difficulties in accurate exposure assessment, the heterogeneous nature of SLE, and the challenge of assessing photosensitivity, a feature of SLE, which often precedes its diagnosis.

The relationship between ambient ultraviolet radiation (UVR) and objectively measured personal UVR exposure dose is modified by season and latitude

Despite the widespread use of ambient ultraviolet radiation (UVR) as a proxy measure of personal exposure to UVR, the relationship between the two is not well-defined.

Investigation on the capability of polysulphone for measuring biologically effective solar UV exposures

Polysulphone (PS) dosimetry is a well-known technique broadly used to assess the erythemally effective solar UV dose received by anatomical sites (personal exposure). We investigate the capability of PS dosimetry to convert doses absorbed by PS badges into biologically effective solar UV exposures taking as examples two relevant effects for human skin: erythema induction and pre-vitamin D3 production. PS calibration curves for erythemal and pre-vitamin D3 were distinctly determined by using an empirical relationship between the biologically effective UV exposures and the PS absorbance change. This relationship is parameterized by a coefficient, distinct for each of the two considered biological effects, multiplying the same cubic polynomial function. It is shown how the multiplying coefficient is related to the ratio between the biologically effective and the PS weighted irradiances which is the prevailing factor affecting the accuracy of the calibration and, consequently, the capability of PS films for measuring biologically effective solar UV exposures. The points addressed in this paper can be extended to other biological effects of interest whose action spectra have some similarity with the PS film response.

Individual, environmental, and meteorological predictors of daily personal ultraviolet radiation exposure measurements in a United States cohort study

BACKGROUND

Individual exposure to ultraviolet radiation (UVR) is challenging to measure, particularly for diseases with substantial latency periods between first exposure and diagnosis of outcome, such as cancer. To guide the choice of surrogates for long-term UVR exposure in epidemiologic studies, we assessed how well stable sun-related individual characteristics and environmental/meteorological factors predicted daily personal UVR exposure measurements.

METHODS

We evaluated 123 United States Radiologic Technologists subjects who wore personal UVR dosimeters for 8 hours daily for up to 7 days (N = 837 days). Potential predictors of personal UVR derived from a self-administered questionnaire, and public databases that provided daily estimates of ambient UVR and weather conditions. Factors potentially related to personal UVR exposure were tested individually and in a model including all significant variables.

RESULTS

The strongest predictors of daily personal UVR exposure in the full model were ambient UVR, latitude, daily rainfall, and skin reaction to prolonged sunlight (R(2) = 0.30). In a model containing only environmental and meteorological variables, ambient UVR, latitude, and daily rainfall were the strongest predictors of daily personal UVR exposure (R(2) = 0.25).

CONCLUSIONS

In the absence of feasible measures of individual longitudinal sun exposure history, stable personal characteristics, ambient UVR, and weather parameters may help estimate long-term personal UVR exposure.

New approach for particulate exposure monitoring: determination of inhaled particulate mass by 24 h real-time personal exposure monitoring

The objectives of this study were to measure particulate pollution (PM(10), PM(2.5), and PM(1.0)) continuously (24 h/day for 7 day) using real-time exposure monitoring and to estimate total inhalation mass using breathing rate and time-activity. Breathing rates were calculated from measured heart rates. Participants were asked to record a time-activity diary every 15 min. Five microenvironments were defined based on the time-activity diary: home, workplace/school, other indoor, outdoor, and transportation. The average masses of inhaled PM(10) were 530, 316, and 280 μg/day for two office workers, a housewife, and three students, respectively; those of PM(2.5) were 316, 279, and 210 μg/day; and those of PM(1.0) were 251, 264, and 187 μg/day, respectively. We found that home and office/school microenvironments were the main contributors of PM(10), PM(2.5), and PM(1.0) inhaled mass during weekdays and weekends because dwelling time was a determinant factor for inhaled mass. Considering microenvironmental concentration, breathing rate, and dwelling time in each microenvironment, indoor home microenvironments were the largest source of particulate inhalation, followed in order by workplace, transportation, other indoor, and outdoor microenvironments. 34.6% and 69.6% of PM(10) inhalation mass were accumulated in home microenvironments during weekdays and weekends, respectively. The inhaled mass of particulate <1.0 μm (PM(1.0)) in size occupied largest, followed in order by particulate 10-2.5 μm (coarse particle) and 2.5-1.0 μm in size for all occupations.

Development and validation of sunlight exposure measurement questionnaire (SEM-Q) for use in adult population residing in Pakistan

Background

Vitamin D deficiency has been identified as a major public health problem worldwide. Sunlight is the main source of vitamin D and its measurement using dosimeters is expensive and difficult for use in population-based studies. Hence, the aim of this study was to develop and validate questionnaires to assess sunlight exposure in healthy individuals residing in Karachi, Pakistan.

Methods

Two questionnaires with seven important items for sunlight exposure assessment were developed. Fifty four healthy adults were enrolled based on their reported sunlight exposure (high = 17, moderate = 18, low = 19) from Aga Khan University, Karachi. Over four days, study participants were asked to wear a dosimeter between sunrise and sunset and report time spent and activities undertaken in the sun for questionnaire validation. Algorithm for item weightage was created as an average score based on ultraviolet B percentage received. Blood samples were obtained for serum vitamin D.

Results

The mean time (minutes) spent in sun over 4 days (±SD) was 69.5 (±32) for low, 83.5 (±29.7) for moderate and 329 (±115) for high exposure group. The correlation between average time (minutes) spent in sun over 4 days and mean change in absorbance of UV dosimeters for 4 days was 0.60 (p < 0.01). Correlation between average score and vitamin D levels was found to be 0.36 (p = 0.01) for short term questionnaire score, 0.43 (p = 0.01) for long term questionnaire score in summers and 0.48 (p = 0.01) in winters.

Conclusions

The sunlight exposure measurement questionnaires were valid tools for use in large epidemiological studies to quantify sunlight exposure.

Validation of a light questionnaire with real-life photopic illuminance measurements: the Harvard Light Exposure Assessment questionnaire

BACKGROUND

Shift work, which necessitates light exposure at night, is now considered a probable carcinogen. To study the effects of light on chronic diseases like cancer, methods to measure light exposure in large observational studies are needed. We aimed to investigate the validity of self-reported current light exposure.

METHODS

We developed a self-administered semiquantitative light questionnaire, the Harvard Light Exposure Assessment (H-LEA) questionnaire, and compared photopic scores derived from this questionnaire with actual photopic and circadian measures obtained from a real-life 7-day light meter application among 132 women (85 rotating night shift workers and 47 day workers) participating in the Nurses' Health Study II.

RESULTS

After adjustment for age, body mass index (BMI), collection day, and night work status, the overall partial Spearman correlation between self-report of light exposure and actual photopic light measurements was 0.72 (P < 0.001; Kendall τ = 0.57) and 0.73 (P < 0.0001; Kendall τ = 0.58) when correlating circadian light measurements. There were only minimal differences in accuracy of self-report of light exposure and photopic or "circadian" light measurement between day (r = 0.77 and 0.78, respectively) and rotating night shift workers (r = 0.68 and 0.69, respectively).

CONCLUSIONS

The results of this study provide evidence of the criterion validity of self-reported light exposure using the H-LEA questionnaire.

IMPACT

This questionnaire is a practical method of assessing light exposure in large-scale epidemiologic studies.

Applicability of the polysulphone horizontal calibration to differently inclined dosimeters

Polysulphone (PS) dosimetry has been a widely used technique for more than 30 years to quantify the erythemally effective UV dose received by anatomic sites (personal exposure). The calibration of PS dosimeters is an important issue as their spectral response is different from the erythemal action spectrum. It is performed exposing a set of PS dosimeters on a horizontal plane and measuring the UV doses received by dosimeters using calibrated spectroradiometers or radiometers. In this study, data collected during PS field campaigns (from 2004 to 2006), using horizontal and differently inclined dosimeters, were analyzed to provide some considerations on the transfer of the horizontal calibration to differently inclined dosimeters, as anatomic sites usually are. The role of sky conditions, of the angle of incidence between the sun and the normal to the slope, and of the type of surrounding surface on the calibration were investigated. It was concluded that PS horizontal calibrations apply to differently inclined dosimeters for incidence angles up to approximately 70° and for surfaces excluding ones with high albedo. Caution should be used in the application of horizontal calibrations for cases of high-incidence angle and/or high albedo surfaces.

Validity of self-reported solar UVR exposure compared with objectively measured UVR exposure

BACKGROUND

Reliance on verbal self-report of solar exposure in skin cancer prevention and epidemiologic studies may be problematic if self-report data are not valid due to systematic errors in recall, social desirability bias, or other reasons.

METHODS

This study examines the validity of self-reports of exposure to ultraviolet radiation (UVR) compared to objectively measured exposure among children and adults in outdoor recreation settings in 4 regions of the United States. Objective UVR exposures of 515 participants were measured using polysulfone film badge UVR dosimeters on 2 days. The same subjects provided self-reported UVR exposure data on surveys and 4-day sun exposure diaries, for comparison to their objectively measured exposure.

RESULTS

Dosimeter data showed that lifeguards had the greatest UVR exposure (24.5% of weekday ambient UVR), children the next highest exposures (10.3% ambient weekday UVR), and parents had the lowest (6.6% ambient weekday UVR). Similar patterns were observed in self-report data. Correlations between diary reports and dosimeter findings were fair to good and were highest for lifeguards (r = 0.38-0.57), followed by parents (r = 0.28-0.29) and children (r = 0.18-0.34). Correlations between survey and diary measures were moderate to good for lifeguards (r = 0.20-0.54) and children (r = 0.35-0.53).

CONCLUSIONS

This is the largest study of its kind to date, and supports the utility of self-report measures of solar UVR exposure.

IMPACT

Overall, self-reports of sun exposure produce valid measures of UVR exposure among parents, children, and lifeguards who work outdoors.

Occupational and environmental exposures and risk of systemic lupus erythematosus: silica, sunlight, solvents

OBJECTIVES

We examined occupational and non-occupational exposures in relation to risk of SLE in a case-control study conducted through the Canadian Network for Improved Outcomes in SLE (CaNIOS).

METHODS

SLE cases (n = 258) were recruited from 11 rheumatology centres across Canada. Controls (without SLE, n = 263) were randomly selected from phone number listings and matched to cases by age, sex and area of residence. Data were collected using a structured telephone interview.

RESULTS

An association was seen with outdoor work in the 12 months preceding diagnosis [odds ratio (OR) 2.0; 95% CI 1.1, 3.8]; effect modification by sun reaction was suggested, with the strongest effect among people who reported reacting to midday sun with a blistering sunburn or a rash (OR 7.9; 95% CI 0.97, 64.7). Relatively strong but imprecise associations were seen with work as an artist working with paints, dyes or developing film (OR 3.9; 95% CI 1.3, 12.3) and work that included applying nail polish or nail applications (OR 10.2; 95% CI 1.3, 81.5). Patients were more likely than controls to report participation in pottery or ceramics work as a leisure activity, with an increased risk among individuals with a total frequency of at least 26 days (OR 2.1; 95% CI 1.1, 3.9). Analyses of potential respirable silica exposures suggested an exposure-response gradient (OR 1.0, 1.4. and 2.1 for zero, one and two or more sources of exposure, respectively; trend test P < 0.01).

CONCLUSIONS

This study supports the role of specific occupational and non-occupational exposures in the development of SLE.

UV exposition during typical lifestyle behavior in an urban environment

In this study the personal exposure to solar UV radiation in an urban environment was measured. Lifestyle in an urban environment is characterized by staying indoors during most of the day. Furthermore, the ambient UV radiation is mitigated by shadowing by buildings. The aim of the study was to find out activities which may contribute to UV-induced health risk in a low exposure environment. Exposure was measured during typical outdoor activities: shopping, walking, sitting in a sidewalk café, cycling, sightseeing and at an open-air pool (solar elevation: 10 degrees-70 degrees). Measurements were taken with an optoelectronic device which was fixed on the chest. Besides the UV Index we used the sun burn time (SBT) for risk assessments. Generalization of our results was made by calculating ratios of personal exposure to the ambient UV radiation. UV exposure was by far the highest when our study subject stayed at the swimming pool. The SBT was around 30 min for melano-compromised skin type. For all other activities, except shopping, the SBT range up to 1 h. With respect to photodamage we found that at high solar elevation (>45 degrees) photoprotective measures should be applied for certain activities even within a city.

Vitamin D intake needed to maintain target serum 25-hydroxyvitamin D concentrations in participants with low sun exposure and dark skin pigmentation is substantially higher than current recommendations

Cutaneous cholecalciferol synthesis has not been considered in making recommendations for vitamin D intake. Our objective was to model the effects of sun exposure, vitamin D intake, and skin reflectance (pigmentation) on serum 25-hydroxyvitamin D (25[OH]D) in young adults with a wide range of skin reflectance and sun exposure. Four cohorts of participants (n = 72 total) were studied for 7-8 wk in the fall, winter, spring, and summer in Davis, CA [38.5 degrees N, 121.7 degrees W, Elev. 49 ft (15 m)]. Skin reflectance was measured using a spectrophotometer, vitamin D intake using food records, and sun exposure using polysulfone dosimeter badges. A multiple regression model (R(2) = 0.55; P < 0.0001) was developed and used to predict the serum 25(OH)D concentration for participants with low [median for African ancestry (AA)] and high [median for European ancestry (EA)] skin reflectance and with low [20th percentile, approximately 20 min/d, approximately 18% body surface area (BSA) exposed] and high (80th percentile, approximately 90 min/d, approximately 35% BSA exposed) sun exposure, assuming an intake of 200 iu/d (5 ug/d). Predicted serum 25(OH)D concentrations for AA individuals with low and high sun exposure in the winter were 24 and 42 nmol/L and in the summer were 40 and 60 nmol/L. Corresponding values for EA individuals were 35 and 60 nmol/L in the winter and in the summer were 58 and 85 nmol/L. To achieve 25(OH)D > or =75 nmol/L, we estimate that EA individuals with high sun exposure need 1300 iu/d vitamin D intake in the winter and AA individuals with low sun exposure need 2100-3100 iu/d year-round.

Assessment of lifetime cumulative sun exposure using a self-administered questionnaire: reliability of two approaches

Few studies have evaluated the reliability of lifetime sun exposure estimated from inquiring about the number of hours people spent outdoors in a given period on a typical weekday or weekend day (the time-based approach). Some investigations have suggested that women have a particularly difficult task in estimating time outdoors in adulthood due to their family and occupational roles. We hypothesized that people might gain additional memory cues and estimate lifetime hours spent outdoors more reliably if asked about time spent outdoors according to specific activities (an activity-based approach). Using self-administered, mailed questionnaires, test-retest responses to time-based and to activity-based approaches were evaluated in 124 volunteer radiologic technologist participants from the United States: 64 females and 60 males 48 to 80 years of age. Intraclass correlation coefficients (ICC) were used to evaluate the test-retest reliability of average number of hours spent outdoors in the summer estimated for each approach. We tested the differences between the two ICCs, corresponding to each approach, using a t test with the variance of the difference estimated by the jackknife method. During childhood and adolescence, the two approaches gave similar ICCs for average numbers of hours spent outdoors in the summer. By contrast, compared with the time-based approach, the activity-based approach showed significantly higher ICCs during adult ages (0.69 versus 0.43, P = 0.003) and over the lifetime (0.69 versus 0.52, P = 0.05); the higher ICCs for the activity-based questionnaire were primarily derived from the results for females. Research is needed to further improve the activity-based questionnaire approach for long-term sun exposure assessment.