A randomized trial of a wearable UV dosimeter for skin cancer prevention

Background

Non-melanoma skin cancer (NMSC) is the most prevalent cancer in the United States. Despite guidelines on ultraviolet (UV) avoidance, it remains difficult for people to assess their exposure, as UV is invisible and the onset of UV-induced symptoms is delayed.

Methods

In a prospective randomized trial, 97 elderly patients with a history of actinic keratoses (AK) were followed over 6 months. Fifty patients received UV counseling from a dermatologist and a wearable UV dosimeter that provided real-time and cumulative UV exposure. Forty-seven patients received only UV counseling from a dermatologist.

Results

Over 75% of participants recorded UV exposure at least once a week during the summer. After 6 months of intervention, when comparing the device group to the control group, we observed a non-significant 20% lower ratio of incidence rates of AKs (95% CI = [-41, 55%], p-value = 0.44) and a significant 95% lower ratio of incidence rates of NMSCs (95% CI = [33, 99.6%], p-value = 0.024). Surveys demonstrated that the control group's score in self-perceived ability to participate in social activities significantly increased by 1.2 (p-value = 0.04), while in the device group, this score non-significantly decreased by 0.9 (p-value = 0.1). We did not observe changes, or between-group differences, in anxiety and depression surveys.

Conclusion

This pilot clinical trial has a short duration and a small sample size. However, device adherence and quality of life questionnaires suggest a smartphone-connected wearable UV dosimeter is well accepted by an elderly population. This trial also indicates that a wearable UV dosimeter may be an effective behavioral change tool to reduce NMSC incidence in an elderly population with a prior history of AKs.Clinical trial registration: clinicaltrials.gov, identifier NCT03315286.

Solar UV Measured under Built-Shade in Public Parks: Findings from a Randomized Trial in Denver and Melbourne

Reducing exposure to ultraviolet radiation (UV) is crucial for preventing UV-induced diseases of the skin and eyes. Shade may offer significant protection from UV. More empirical research to quantify the UV protection offered from built shade is needed to guide disease prevention practices and confidence in investment in shade. This study quantified UV levels under built-shade relative to unshaded passive recreation areas (PRAs) over summer months in parks in two cities. In a randomized controlled trial, n = 1144 UV measurements were conducted at the center and periphery of PRAs in a total sample of 144 public parks as part of pretest and posttest measures of use of the PRAs by park visitors for three recruitment waves per city during 2010 to 2014. Following pretest, 36 PRAs received built-shade and 108 did not. Regression analyses modelled pre-post change in UV (Standard Erythemal Dose (SED) per 30 min) at PRAs; and environmental predictors. Mean UV at the center of built-shade PRAs decreased from pretest to posttest (x¯ = 3.39, x¯ = 0.93 SED), a change of x¯ = -3.47 SED relative to control PRAs (p < 0.001) adjusting for the covariates of ambient SED, (cosine) solar elevation and cloud cover. Clouds decreased and solar elevation increased UV levels under shade. No significant differences in UV by shade design occurred. A substantial reduction in exposure to UV can be achieved using built-shade with shade cloth designs, offering considerable protection for shade users. Supplementary sun protection is recommended for extended periods of shade use during clear sky days.

Solar Ultraviolet Radiation Temporal Variability Analysis from 2-Year of Continuous Observation in an Amazonian City of Brazil

Solar ultraviolet radiation (UVR) is a highly energetic component of the solar spectrum that needs to be monitored because of the effects on human health and on the ecosystems. In Brazil, few cities monitor UVR, especially in the Amazon region which is particularly poor in observation. This work is the first to address the short-term (2-year) time variability of UVR in Santarém (2°25′ S, 54°44′ W, 51 m) using ground-based measurements. The irradiance in the wavelength range of 250–400 nm was investigated on different time scales. Furthermore, to understand how the UVR varies without the influence of clouds, the hours corresponding to the clear sky condition were analyzed as well as the hours in all sky conditions. Regarding the averages, there is a slight variation over the year. In all sky and clear sky conditions, the dry season had a higher average than the rainy season, despite the slight difference. Also, both in all-sky and clear-sky conditions the maximums occurred around local solar noon, and reached a maximum of 87 in the dry season under the clear sky condition. Further understanding of the radiative effects of the clouds in UVR time variability is considered essential for future research. This study can serve as a reference for UVR levels in this region where no other ground-based UVR measurements are made.

The Ultraviolet Index Is Well Estimated by the Terrestrial Irradiance at 310 nm

Ultraviolet (UV) exposure significantly contributes to non-melanoma skin cancer. In the context of health, UV exposure is the product of time and the UV Index (UVI), a weighted sum of the irradiance I(λ) over all wavelengths from λ = 250 to 400 nm. In our analysis of the United States Environmental Protection Agency’s UV-Net database of over 400,000 spectral irradiance measurements taken over several years, we found that the UVI is well estimated by 77 I₃₁₀. To further understand this result, we applied an optical atmospheric model to generate terrestrial irradiance spectra and found that it applies across a wide range of conditions. An accurate UVI radiometer can be built from a photodiode covered by a bandpass filter centered at 310 nm.

Review of Wearable and Portable Sensors for Monitoring Personal Solar UV Exposure

Sunlight is one of the main environmental resources that keeps all the organisms alive on earth. The ultraviolet (UV) radiation from the sun is essential for vitamin D synthesis in the human body, which is crucial for bone and muscle health. In addition, sun exposure also helps to reduce the risk of some cardiovascular diseases and cancers. However, excessive UV exposure can lead to adverse effects, including some eye diseases, premature aging, sunburn and skin cancers. The solar UV irradiance itself depends on many environmental factors. In fact, the UV index reported in weather forecasts is an estimation under cloudless conditions. Personal UV exposure also depends on one's outdoor activities and habits. Furthermore, the UV intake depends on the skin sensitivity. Therefore, there is a need for research into monitoring the optimal daily UV exposure for health benefits, without developing potential health risks. To facilitate the monitoring of solar UV intensity and cumulative dose, a variety of UV sensors have been developed in the past few decades and many are commercially available. Examples of sensors being marketed are: portable UV dosimeter, wearable UV radiometer, personal UV monitor, and handheld Solarmeter®. Some of the UV sensors can be worn as personal health monitors, which promote solar exposure protection. The paper provides a comprehensive review of the wearable and portable UV sensors for monitoring personal UV exposure, including a discussion of their unique advantages and limitations. Proposals are also presented for possible future research into reliable and practical UV sensors for personal UV exposure monitoring.

Comparison between EPA UV index app and UV monitor to assess risk for solar ultraviolet radiation exposure in agricultural settings in Eastern North Carolina

Agricultural workers are exposed to solar ultraviolet (UV) radiation due to the significant amount of time spent working outdoors. Risk information on UV exposure from the EPA SunWise UV Index mobile app is conveniently available for timely advice on risk management, but its reliability is unknown. The purpose of this study was to determine the reliability of the EPA UV Index app in providing accurate risk information to reduce UV exposure and prevent related illnesses among agricultural workers in eastern North Carolina. UV radiation effective irradiance (UV _eff ) indices were datalogged at two agricultural sites using radiometers from April-August 2019 and were assigned to risk levels (low, moderate, high, very high, extreme) based on the ACGIH^® Threshold Limit Values (TLVs^®). The UV index (UV _app ) and its corresponding risk level were obtained using the app. Hourly UV _app -based risk level assignments were time-matched to their corresponding UV _eff /TLV-based risk level assignments (871 pairs) and analyzed using cross tabulation by determining the percentage of hourly UV _eff /TLV-based risk levels ("gold standard") with the same hourly UV _app -based risk levels, with a larger percentage indicating higher app reliability. Results showed that the app correctly identified 100% of low risk conditions, but its reliability decreased as the UV risk condition became more severe. The app correctly identified 0% of moderate, high and very high risk conditions but instead assigned 100% of them to lower risk levels (30-100% as low risk, 5-70% as moderate risk), indicating that the app was less protective in assessing UV risk. The app correctly identified 0.6% of extreme risk conditions but assigned 99.4% of them to lower risk levels (9.4% as low, 29.7% as moderate, 24.6% as high, 35.8% as very high). It is concluded that the performance of the EPA UV Index app in assessing occupational UV risk is not protective of workers particularly for high risk conditions, and that the use of the app for the assessment of risk to UV exposure in agricultural settings is not recommended.

Solar UV Radiation in the Tropics: Human Exposure at Reunion Island (21° S, 55° E) during Summer Outdoor Activities

Reunion Island is a popular tourist destination with sandy beaches, an active volcano (Piton de la Fournaise), and Piton des Neiges, the highest and most dominant geological feature on the island. Reunion is known to have high levels of solar ultraviolet radiation (UVR) with an ultraviolet index (UVI) which can reach 8 in winter and 16 in summer (climatological conditions). UVR has been linked to skin cancer, melanoma, and eye disease such as cataracts. The World Health Organization (WHO) devised the UVI as a tool for expressing UVR intensity. Thresholds ranging from low (UVI 1-2) to extreme (UVI > 11) were defined depending on the risk to human health. The purpose of the study was to assess UVR exposure levels over three of the busiest tourist sites on the island. UVR was measured over several hours along popular hiking trails around Piton de la Fournaise (PDF), Piton des Neiges (PDN), and St-Leu Beach (LEU). The results were compared with those recorded by the local UV station at Saint-Denis. In addition, cumulative standard erythemal dose (SED) was calculated. Results showed that UVI exposure at PDF, PDN, and LEU were extreme (>11) and reached maximum UVI levels of 21.1, 22.5, and 14.5, respectively. Cumulative SEDs were multiple times higher than the thresholds established by the Fitzpatrick skin phototype classification. UVI measurements at the three study sites showed that Reunion Island is exposed to extreme UVR conditions. Public awareness campaigns are needed to inform the population of the health risks related to UVR exposure.

Technological Advances in Herpetoculture

Technology plays a vital role in herpetoculture because ectothermic animals rely on their environment to carry out basic physiologic functions. Controlling the environment appropriately ensures the health and welfare of captive reptiles and amphibians. This article summarizes some of the technological advances and products currently available, including lighting, climate control, and recordkeeping.

Solar UV Radiation in Saint-Denis, La Réunion and Cape Town, South Africa: 10 years Climatology and Human Exposure Assessment at Altitude

Solar ultraviolet radiation (UVR) monitoring is important since it depends on several atmospheric parameters which are associated with climate change and since excess solar UVR exposure and has significant impacts on human health and wellbeing. The objective of this study was to investigate the trends in solar UVR during a decade (2009–2018) in Saint-Denis, Reunion Island (20.9°S, 55.5°E, 85 m ASL) and Cape Town, South Africa (33.97°S, 18.6°E, 42 m ASL). This comparison was done using total daily erythema exposure as derived from UVR sensors continuously at both sites. Climatology over the 10-year period showed extreme UVR exposure for both sites. Slight changes with opposite trends were found, +3.6% at Saint-Denis and −3.7% at Cape Town. However, these two sites often experience extreme weather conditions thereby making the trend evaluation difficult. Human exposure assessment was performed for hiking activities at two popular high-altitude hiking trails on the Maïdo–Grand Bénare (Reunion) and Table Mountain (Cape Town) with a handheld radiometer. Extreme exposure doses of 64 SED and 40 SED (Standard Erythemal Dose, 1 SED = 100 J.m−2) were recorded, respectively. These high exposure doses highlight the importance of raising public awareness on the risk related to excess UVR exposure at tourist sites, especially those at high altitude.

Ultraviolet radiation sensors: a review

Knowledge of when to actively modify outdoor sun protective behaviour is crucial for sun safety and should be based upon personal susceptibility to sunburn and the intensity of the ultraviolet radiation dose during outdoor exposure. To facilitate measurements of dose and exposure, non-scientific and research-grade instruments measuring different exposure parameters of solar radiation are commercially available. These devices have been marketed as weather stations, purpose-built UVI display stations, portable dosimeters, handheld solarmeters, watches, and even stickers that can be worn. According to their measurements, the public can be educated and reminded to adopt appropriate sun safety practices such as limiting midday sun exposure, seeking shade, wearing protective clothing such as a broad-brimmed hat, and regularly applying and reapplying broad-spectrum sunscreen. There are many different commercial devices and smart phone applications (apps) that allow the public to be informed about current ultraviolet radiation levels in their immediate area, but each aims to enable the public to practise good sun safety behaviour. Naturally, each device is not without its various limitations and unique advantages. This study explores the ways in which ultraviolet radiation sensors can provide an accurate and highly convenient way of practising good sun safety behaviour in various contexts of high sun exposure such as playgrounds, tourist attractions, workplaces, and swimming pools. However, the author advises caution on the use of personal meters that have not been validated for their reliability and accuracy as public health tools.

UV Index monitoring in Europe

The UV Index was established more than 20 years ago as a tool for sun protection and health care. Shortly after its introduction, UV Index monitoring started in several countries either by newly acquired instruments or by converting measurements from existing instruments into the UV Index. The number of stations and networks has increased over the years. Currently, 160 stations in 25 European countries deliver online values to the public via the Internet. In this paper an overview of these UV Index monitoring sites in Europe is given. The overview includes instruments as well as quality assurance and quality control procedures. Furthermore, some examples are given about how UV Index values are presented to the public. Through these efforts, 57% of the European population is supplied with high quality information, enabling them to adapt behaviour. Although health care, including skin cancer prevention, is cost-effective, a proportion of the European population still doesn't have access to UV Index information.

Controlling sunbathing safety during the summer holidays - The solar UV campaign at Baltic Sea coast in 2015

Information regarding the intensity of surface UV radiation, provided for the public, is frequently given in terms of a daily maximum UV Index (UVI), based on a prognostic model. The quality of the UV forecast depends on the accuracy of column amount of ozone and cloudiness prediction. Daily variability of UVI is needed to determine the risk of the UV overexposure during outdoor activities. Various methods of estimating the temporary UVI and the maximum duration of UV exposures (received a dose equal to minimal erythemal dose - MED), at the site of sunbathing, were compared. The UV indices were obtained during a field experiment at the Baltic Sea coast in the period from 13th to 24th July 2015. The following UVI calculation models were considered: UVI measurements by simple hand-held biometers (Silver Crest, Oregon Scientific, or more advanced Solarmeter 6.5), our smartphone models based on cloud cover observations at the site and the cloudless-sky UVI forecast (available for any site for all smartphone users) or measured UVI, and the 24h weather predictions by the ensemble set of 10 models (with various cloud parameterizations). The direct UV measurements, even by a simple biometer, provided useful UVI estimates. The smartphone applications yielded a good agreement with the UV measurements. The weather prediction models for cloudless-sky conditions could provide valuable information if almost cloudless-sky conditions (cloudless-sky or slightly scattered clouds) were observed at the sunbathing site.

Comparing Handheld Meters and Electronic Dosimeters for Measuring Ultraviolet Levels under Shade and in the Sun

This study aimed to compare the validity, reliability and practicality of alternative portable methods for measuring erythemal UVR levels in passive recreation areas in public parks. UVR levels were measured for point in time comparisons between Solarmeter 6.5 handheld meters and time-stamped electronic dosimeters in a large central park in Melbourne, Australia. Observations were made at 20 locations in the park by two research assistants under two conditions: (1) matched shade (2) contrasting shade-no shade. Comparisons were also made with scientific instruments on the UVR monitoring station rooftop and by remotely selecting UV records and forecasts on cloud-free dates of park observations. There was good agreement between the portable UVR instruments in the park setting as confirmed via Bland Altman plots, while the dosimeter appeared less sensitive to change in shade conditions. The rooftop measurements showed that the Solarmeter 6.5 UVR readings were comparable to those of the adjacent rooftop instruments. The practicalities of using the dosimeters and Solarmeters for behavioral studies are discussed. These findings provide a basis for use of the Solarmeter 6.5 to measure changes in UVR levels due to different environmental conditions with relative accuracy for intervention studies in outdoor settings.

[Sun exposure at school: Evaluation of risk (erythema dose), benefits (vitamin-D synthesis) and behaviour among children in France]

BACKGROUND

To better understand the potential risk associated with sun exposure during the school year, we decided to evaluate behaviour, risk [UV index (UVI), minimal erythema dose (MED)] and benefits (vitamin-D synthesis) of sun exposure in primary schoolchildren in France, as well as the various sun protection methods used for children.

MATERIAL AND METHODS

We performed the study on a sunny day (July 24) in a school in Antony (France). Evaluation of UVI (with calculation of MED) and the amount of vitamin D synthesized according to exposed body surface area and phototype were performed every 15minutes from 9 a.m. to 5 p.m. The effects of albedo and shade on UVI were assessed in 8 different locations at the school. The sun-protection measures used by the children were systematically evaluated.

RESULTS

Fifty-seven children were evaluated; the maximum UVI was 7.2 and the maximum temperature was 30.7°C. Irrespective of phototype and clothing, 1 MED was reached and an adequate level of vitamin D was synthesized in the skin before midday. Albedo had little impact on irradiation. The amount of protection afforded by shadow varied greatly, with the highest level occurring in the covered courtyard (99.5% reduction of UVI) and the lowest in the shadow of buildings (53.7% reduction of UVI). With strict sun protection measures concerning dress, children reached 1 MED before synthesizing 1000IU of vitamin D, but with clothing "suited to high temperatures", 1000IU of vitamin D were synthetized before 1 MED was reached. Compliance with photoprotection measures was poor. Regardless of duration of exposure during the day (minimal model: two play breaks+lunchtime break) and of skin phototype, at least 1.5 MED was reached during the day.

STUDY LIMITATIONS

This was an experimental study ignoring children's actual behaviour (movement, sweating, application of sun protection products, etc.). Moreover, due to weather conditions, the study was performed at a recreation centre in July and not during the "standard" school year.

CONCLUSION

Sun protection campaigns should naturally be directed chiefly towards children for several reasons relating to solar risk and learning. This study shows the complex link between UV, MED, vitamin D as well as the difficulties of implementing solar protection measures in schools in France.

Ozone depletion and climate change: impacts on UV radiation

Percentage changes in the UV Index (UVI) for 2090 relative to 2015 due to changes in ozone (left) and aerosols (right) only. Large decreases are projected over Antarctica due to stratospheric ozone recovery. Increases are projected for parts of Asia due to decreases in aerosols, partly reversing the possible large reductions in UVI after the 1950s.

Shade provision for toddlers at swimming pools in Melbourne

This study assessed the UVR protection provided by shade structures over toddler pools at swimming pool centers in Melbourne. The UVR protection was measured using a combination of UV sensitive polysulfone film to derive an average value during the middle of the day (1-2 P.M.) and handheld UV meters to derive the time variability in UV protection between 11 A.M. and 3 P.M. The amount of UVR protection provided by the shade structures depended upon a number of factors such as location, size, and materials used, but generally ranged from a protection factor (PF) of 2 to ~ 16. The higher PFs were generally for larger structures or where the shade had other structures nearby. The handheld UV meter measurements showed the UV protection varied with position under the shade structure as well as with time of day. While provision of shade structures is becoming more widespread around Australia, improving the shade availability at the pool centers overall, the application of recommendations regarding the provision of shade has been followed to a varying degree by many of the pools visited in this study. In many cases, continued further improvements can be made to provide more adequate protection and further reduce UV exposures.

Comparison of two personal ultraviolet index monitors for sun awareness in South Africa

Exposure to solar ultraviolet (UV) radiation is known to have both adverse and beneficial consequences for human health. Sunburn and skin cancer are probably the most well-known acute and chronic adverse health impacts. These themes have recently been discussed in the media for the general public; consequently interest in sun protection is growing. The promotion of the use of practical personal strategies to reduce adverse health risks, such as healthy sun behaviour, sun protection mechanisms and solar ultraviolet radiation awareness tools, is increasing. One such tool is the personal UV index (UVI) monitor, promoted commercially as a viable tool for sun awareness; however, such instruments have not been scientifically evaluated in a South African context. Here, two different types of personal UVI monitors, commercially available in South Africa, were compared with a research-grade UVB biometer for a continuous 7-h period on 02 March 2012 in Pretoria. One of the two personal UVI monitors showed reasonable agreement with the UVB biometer, whereas the other monitor overestimated UVI by up to 4 UVI units. When comparing two identical products manufactured by the same company, one monitor overestimated UVI twofold, suggesting inter-instrument variability may be a concern. Commercially available, personal UVI monitors should be used with caution as a public health tool for sun awareness in South Africa.

[Understanding and use of the global solar UV index ("UV index") by French dermatologists]

BACKGROUND

The principal risk factor for development of skin cancers is exposure to ultraviolet (UV) radiation. The universal solar UV index (UVI) consists of a simple measurement of UV radiation at the earth's surface, which provides an indicator of the risk of skin lesions in the absence of protective measures and taking into account individual phototype. The UVI is recommended by the WHO and is used to educate populations about the need to take protective measures in the event of exposure to UV radiation. There have been very few studies to assess understanding of this index, and these have been conducted primarily among the general population. Our study assesses understanding and use of the UVI among dermatologists in metropolitan France.

MATERIALS AND METHODS

This survey was conducted in December 2011 among 400 randomly selected French dermatologists. The questions asked concerned their personal and professional knowledge and their use of the UVI.

RESULTS

We analysed 165 (41.5%) of the answers. The UVI was known to 79% of the dermatologists questioned. Less than one third of dermatologists knew the key values in the UVI. Less than half of the dermatologists aware of the UVI reported acting upon the values in question. Only 12.1% of the dermatologists said that they used the index in their communication concerning prevention of sunburn.

DISCUSSION

The results of our study show that the UVI is poorly known and not very widely used among dermatologists in France. This index, readily understood by anyone, could be incorporated by dermatologists in their prevention messages concerning solar radiation and it could be used throughout the year, particularly in target populations such as schoolchildren and children taking part in outdoor sports.

Outdoor sports and risk of ultraviolet radiation-related skin lesions in children: evaluation of risks and prevention

BACKGROUND

Excessive ultraviolet (UV) radiation exposure can cause skin cancers, skin photoageing and cataracts. Children are targeted by sun-protection campaigns because high sun exposure and sunburn in childhood increase the risk of melanoma in adulthood. Little information is available about UV radiation risk and exposure in children who take part in outdoor sports.

OBJECTIVE

To evaluate the risk of developing UV radiation-induced skin lesions run by children who practise outdoor sports, and UV radiation exposure and sun-protection measures during a soccer tournament.

METHODS

Firstly, we evaluated the relationship between melanocytic naevus - a skin lesion linked with exposure to UV radiation - and outdoor sports in 660 11-year-old children. Secondly, we used the occasion of a 1-day soccer tournament held in the spring to evaluate UV radiation-protective measures used by soccer players and the public. We also evaluated the UV radiation index and cloud cover during the tournament, and calculated the UV radiation dose and minimal erythema dose depending on skin phototype.

RESULTS

The naevus count and acquired naevus count measured over the 2 years of the study were higher in the 344 children who practised outdoor sports. Sun-protective measures were insufficient for soccer players and the public.

CONCLUSIONS

This study shows that outdoor sports increase the risk of developing UV radiation-induced skin lesions in childhood. During a 1-day soccer tournament held in the spring, children and their parents were inadequately protected against the sun. These results suggest that sun-protection campaigns should be aimed at children who practise popular outdoor sports.