SOLAR UVR EXPOSURES OF THREE GROUPS OF OUTDOOR WORKERS ON THE SUNSHINE COAST, QUEENSLAND

The solar ultraviolet radiation (UVR) exposures of three groups of outdoor workers, physical education (PE) teachers, ground staff/gardeners and lifeguards were measured using UVR-sensitive polysulfone (PS) film badges. The exposures all took place on the Sunshine Coast, Queensland over 5 consecutive weekdays in November 1992. For the three groups, the shoulder badges received greater UVR exposures than the chest badges, in agreement with previous studies. The PE teachers received the highest UVR exposures while the lifeguards received the least. One of the 5 days of the study was overcast with some rain showers and UVR doses for this day for all groups were significantly lower than on the other 4 days, however the ratio of exposure to ambient remained relatively constant. All groups had measured UVR exposures in excess of occupational guidelines, indicating that protective measures, including education and behavior modification, which are becoming much more common in occupational situations in Australia, are both timely and necessary.     

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 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.     

Measurement of the UVR Exposures of Expeditioners on Antarctic Resupply Voyages†

A study to assess the potential exposure to solar UV radiation of expeditioners on Australian Antarctic resupply voyages was carried out over the Austral summers of 2004/2005 to 2006/2007. Subjects wore UVR‐sensitive polysulphone (PS) badges on the chest for the duration of their working day, which generally ranged from 5 to 10 h, but could be as long as 14 h. Measurements were carried out during unloading of two vessels while they were at the three Australian Antarctic stations. The subjects wore standard Australian Antarctic Division clothing assemblages, although the face and hands and in some cases more of the limbs were uncovered and subjected to exposure to UVR. The badges worn by the subjects received exposures ranging from 0.2 to 18 standard erythemal doses (SEDs), with a median of 3.2 SEDs. However, comparison with occupational exposure limits showed that more than 80% of the subjects’ PS badges received UVR exposures in excess of the limits while 31% received more than five times the limits. Despite sun protection being provided more than 70% of the workers reported mild erythema.     

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.     

Measured solar ultraviolet radiation exposures of outdoor workers in Queensland in the building and construction industry

The risk to outdoor workers of exposure to solar ultraviolet radiation (UVR) has been known for some time, particularly in the building and construction industry, where workers often use little in the way of protection against solar UVR. In recent years there have been attempts by authorities in Australia and in Queensland in particular, where UVR levels in spring and summer are very high to extreme, to instigate and to encourage the use of personal UVR protection by outdoor workers. To quantify UVR exposure of building and construction industry workers involved in typical outdoor work, a study was conducted using UVR-sensitive polysulphone film badges. The results indicated that the doses were significant, often well in excess of recommended exposure limits. The measured exposures varied between trades. Data on the use of personal UVR-protective equipment and the skin type of workers were also collected. Many of the workers had skin types that were sensitive to UVR and showed signs of sunburn. In summary, the study found that at-risk individuals were exposed to extreme levels of UVR, in most cases without adequate and appropriate sun protection.     

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.     

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

Little is known about the validity of self-recorded sun exposure and time spent outdoors for epidemiological research. The aims of the current study were to assess how well participants' self-recorded time outdoors compared to objective measurements of personal UVR doses. We enrolled 124 volunteers aged 40 and above who were identified from targeted subgroups of US radiologic technologists. Each volunteer was instructed to wear a polysulfone (PS) dosimeter to measure UVR on their left shoulder and to complete a daily activity diary, listing all activities undertaken in each 30 min interval between 9:00 A.M. and 5:00 P.M. during a 7 day period. In a linear regression model, self-recorded daily time spent outdoors was associated with an increase of 8.2% (95% CI: 7.3-9.2%) in the personal UVR exposure with every hour spent outdoors. The amount of self-recorded total daily time spent outdoors was better correlated with the personal daily UVR dose for activities conducted near noon time compared to activities conducted in the morning or late afternoon, and for activities often performed in the sun (e.g. gardening or recreation activities) compared to other outdoor activities (e.g. driving) in which the participant is usually shaded from the sun. Our results demonstrated a significant correlation between diary records of time spent outdoors with objective personal UVR dose measurements.     

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.     

Sunburn Risk Among Children and Outdoor Workers in South Africa and Reunion Island Coastal Sites

To estimate potential sunburn risk for schoolchildren and outdoor workers, ground‐based ambient solar ultraviolet radiation (UVR) measurements were converted into possible child (5% of ambient solar UVR) and outdoor worker (20% of ambient solar UVR) solar UVR exposures by skin type and season for three coastal sites: Durban, Cape Point (South Africa) and Saint Denis (Reunion Island, France). Cumulative daily ambient solar UVR levels were relatively high at all sites, especially during summer, with maximum values of about 67, 57 and 74 Standard Erythemal Dose (SED) (1 SED = 100 J m^?2) at Durban, Cape Point and Saint Denis respectively. Sunburn risk was evident for both children and outdoor workers, especially those with skin types I and II (extremely to moderately sensitive) during summer, early autumn and/or late spring at all three sites. Although results need to be verified with real‐time, instantaneous and nonintegrated personal solar UVR measurements, this understanding of sunburn risk is useful for initiating the development skin cancer prevention and sun protection awareness campaigns in both countries.     

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.     

Schoolyard Shade and Sun Exposure: Assessment of Personal Monitoring During Children's Physical Activity

Childhood exposure to ultraviolet radiation (UVR) is a major risk factor for the development of melanoma later in life. However, it is challenging to accurately determine personal outdoor exposure to UVR, specifically erythemally weighted UVR (UV_Ery), due to technological constraints, variable time–activity patterns, and the influence of outdoor environmental design. To address this challenge, this study utilized mobile and stationary techniques to examine the UV_Ery exposures of 14 children in a schoolyard in Lubbock, TX, in spring 2016. The aims of the study were to examine the influence of artificial shade on personal UV_Ery exposures and to assess full sun exposure ratios (ERs) within the same playground microenvironment. On average, personal wrist dosimeters worn during play in the sun measured 18% of the total onsite UV_Ery measured by a stationary UV pyranometer. Shade was found to significantly reduce the personal UV_Ery exposures by 55%, UVB_{280–315 nm} exposures by 91%, and the overall solar radiation by 84%. Substantial benefits can be garnered through focused design of children's recreational space to utilize shade—both natural and artificial—to reduce UVR exposures during play, and to extend safe outdoor stays. Finally, although the wrist is a practical location for a dosimeter, it often underestimates full exposures, particularly during physical activity.     

Sunlight-induced DNA Damage in Marine Micro-organisms Collected Along a Latitudinal Gradient from 70°N to 68°S

We examined ultraviolet radiation (UVR)-induced DNA damage in marine micro-organisms collected from surface seawater along a latitudinal transect in the Central Pacific Ocean from 70°N to 68°S. Samples were collected predawn and incubated under ambient UVR in transparent incubators at in situ temperatures until late afternoon at which time they were filtered into primarily bacterioplankton and eukaryotic fractions. Cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts [(6-4)PDs] were quantified in DNA extracts using radioimmunoassays. UVB was lowest in the polar regions and highest near the equator and correlations between UVB and DNA damage were observed. The eukaryotic fraction showed significant CPDs across the entire transect; (6-4)PDs were detected only in the tropics. The bacterial fraction showed no accumulation of (6-4)PDs at any latitude, although residual (6-4)PDs were observed. Bacterial cell volumes were greatest in the sub-Arctic and northern temperate latitudes and lower in the tropics and southern hemisphere, a unique observation that parallels Bergmann's rule. A strong negative correlation was observed between cell volume and CPDs. The environmental impact of solar UVR on marine micro-organisms in the open ocean is complex and our results suggest that several factors such as DNA repair, cell size, temperature, salinity, nutrients and species composition are important in determining relative sensitivity.     

The Simulated Ocular and Whole-Body Distribution of Natural Sunlight to Kiteboarders: A High-Risk Case of UVR Exposure for Athletes Utilizing Water Surfaces in Sport

Kiteboarding is an aquatic sporting discipline that has not yet been considered in the literature to date in terms of solar ultraviolet radiation (UVR) measurement. Kiteboarders need to look upward and are placed obliquely relative to the horizon when towed behind an overhead kite over a reflective water surface. This research defines the typical body surface orientation of a kiteboarder in motion through video vector analysis and demonstrates the potential risk to ocular and skin surface damage through practical measurement of solar UVR using a manikin model. Video analysis of 51 kiteboarders was made to construct skeletal wireframes showing the surface orientation of the leg, thigh, spine, humerus, lower arm and head of a typical kiteboarder. Solar UVR dosimeter measurements made using a manikin model demonstrate that the vertex and anterior surfaces of the knee, lower leg and lower humerus received 89%, 90%, 80% and 63% of the available ambient UVR, respectively, for a typical kiteboarder who is tilted back more than 15° from vertical while in motion. Ocular (periorbital) exposures ranged from 56% to 68% of ambient. These new findings show that the anterior skin surfaces of kiteboarders and the eye are at elevated risk of solar UVR damage.     

Intercomparison of Effective Erythemal Irradiance Measurements from Two Types of Broad-Band Instruments during June 1995

The biologically effective global solar ultraviolet radiation (UVR) measurements from a multiband UVR monitor and a conventional broadband UVR monitor are compared. The measurements were performed during the varied weather conditions of June 1995. We compared the daily total exposures measured by both instruments, as well as the ratio of the measured doses throughout the course of each day. The daily total exposures agreed within approximately 11% throughout the month. The ratio between the measured doses held at 1.12 between 0900 and 1700 h (solar zenith angles ?16-52°). The ratio decreased from 1.12 to 0.90 during the next 90 min outside that period (solar zenith angles ?52-72°) and decreased further beyond that point. Spectral response and cosine response mismatch between the instruments are discussed as the possible cause of discrepancies between the measured doses. Implications for erythemal irradiance monitoring and suggestions for further study are discussed.     

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.     

Measurements of the UVR protection provided by hats used at school

The importance of protection against solar ultraviolet radiation (UVR) in childhood has lead to SunSmart policies at Australian schools, in particular primary schools, where children are encouraged and in many cases required to wear hats at school. Hat styles change regularly and the UVR protection provided by some of the hat types currently used and recommended for sun protection by the various Australian state cancer councils had not been previously evaluated. The UVR protection of the hats was measured using UVR sensitive polysulphone film badges attached to different facial sites on rotating headforms. The sun protection type hats included in this study were broad-brimmed hats, "bucket hats" and legionnaires hats. Baseball caps, which are very popular, were also included. The broad-brimmed hats and bucket hats provided the most UVR protection for the six different sites about the face and head. Legionnaires hats also provided satisfactory UVR protection, but the caps did not provide UVR protection to many of the facial sites. The highest measured UVR protection factors for facial sites other than the forehead were 8 to 10, indicating that, while some hats can be effective, they need to be used in combination with other forms of UVR protection.     

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.     

International Intercomparison of Solar UVR Spectral Measurement Systems in Melbourne in 2013

Monitoring ambient solar UVR levels provides information on how much there is in both real time and historically. Quality assurance of ambient measurements of solar UVR is critical to ensuring accuracy and stability and this can be achieved by regular intercomparisons of spectral measurement systems with those of other organizations. In October and November of 2013 a solar UVR spectroradiometer from Public Health England (PHE) was brought to Melbourne for a campaign of intercomparisons with a new Bentham spectrometer of Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) and one at the Australian Bureau of Meteorology (BOM), supported by New Zealand's National Institute for Water and Atmosphere (NIWA). Given all three spectroradiometers have calibrations that are traceable to various national standards, the intercomparison provides a chance to determine measurement uncertainties and traceability that support UV measurement networks in Australia, New Zealand and the UK. UV Index measurements from all three systems were compared and ratios determined for clear sky conditions when the scans from each instrument were within 2 min of each other. While wavelengths below 305 nm showed substantial differences between the PHE unit and the two other systems, overall the intercomparison results were encouraging, with mean differences in measured UV Index between the BOM/NIWA and those of PHE and ARPANSA of <0.1% and 7.5%, respectively.     

Suberythemal Sun Exposures at Swedish Schools Depend on Sky Views of the Outdoor Environments – Possible Implications for Pupils’ Health

More scheduled outdoor stay is increasingly advocated for school children. This study measured 2^nd, 5^th and 8^th graders’ erythemal UV‐exposure in September, March and May at four Swedish schools. We related those exposures, as fractions of total available ambient radiation, to the schools outdoor environments differing in amount of shade, vegetation, and peripheral city‐scape quantified as percentage of free sky view calculated from fish‐eye photographs. Exposures correlated with the sky views (with exceptions in May) and were suberythemal. The exposures were also below the threshold limit of the International Commission on Non‐Ionizing Radiation Protection (ICNIRP) for hazard evaluation of UVR but were potentially enough for adequate vitamin D formation according to a cited model calculation – as illustrated in the results and discussed. The school environments, typical in southern and middle Sweden, offer enough shade to protect children from overexposure during seasons with potentially harmful solar UV radiation. Pupils’ outdoor stay may be extended during September and March. In May extended outdoor stay of the youngest pupils requires a more UVR‐protective environment.