Erythemal ultraviolet exposure of cyclists in Valencia, Spain

Occupational exposure to solar ultraviolet radiation in an eastern North Carolina university outdoor setting during the four seasons

Outdoor workers perform tasks throughout the year that expose them to solar ultraviolet radiation (UVR) and increase their risk of UVR-related adverse health effects. Multiple studies on occupational solar UVR exposures during summer have been published but similar investigations during other seasons are limited. The purpose of this study was to assess solar UVR exposure in an eastern North Carolina university setting during all four seasons (fall, winter, spring, and summer) to assess risk for outdoor workers, particularly groundskeepers, throughout the year. UVR effective irradiance (UVReff) was measured by area monitoring using a digital data-logging radiometer and a weatherproof UVR detector for 164 days from October 2020 to October 2021. Results showed that hourly and daily mean UVReff exceeded the 1-hr and 8-hr ACGIH Threshold Limit Values (TLVs), respectively, in all months and seasons at varying degrees. Winter had the lowest mean UVReff (3.4 × 10-3 ± 1.7 × 10-3 mW/cm2), but 91.1% and 100% of the hourly and daily UVReff measurements, respectively, still exceeded the TLVs. This study demonstrates the risk of overexposure to solar UVR among outdoor workers during cold months and seasons and the importance of implementing UVR protection throughout the year.

Ultraviolet sun exposure and sun protection behaviors in outdoor rock climbers

BACKGROUND

Overexposure to sunlight and sunburn are the main preventable causes of skin cancer. Outdoor sports are associated with significant levels of sunlight exposure.

AIMS

We sought to quantify the sun radiation exposure received by outdoor rock climbers and assess their sun exposure habits, sun protection behaviors, attitudes, and knowledge regarding skin cancer.

METHODS

From April to June 2021, outdoor rock climbers contacted via email completed an online validated self-reported questionnaire on sun related habits, behaviors, attitudes and knowledge. As a pilot trial, ten participants wore a personal dosimeter during two outdoor climbing weekends in May and November 2021. Ambient ultraviolet radiation (UVR) was also recorded.

RESULTS

A total of 217 outdoor rock climbers (103 women), mean age 36.8 ± 8.8 years (range 20-70 years) and median climbing practice per week of 8 h (IQR 7.5) were studied. Two in three (65.9%) participants reported at least one sunburn event during the previous rock climbing season. Of the survey respondents, 49.3% reported using sunscreen with SPF ≥ 15, 47% wore sunglasses, and 14.3% indicated they reapplied sunscreen every two hours. The median personal UVR dose measured during the two outdoor climbing weekends analyzed was 5.2 (IQR 1.8) and 8.8 (IQR 1.1) standard erythemal doses, respectively.

CONCLUSIONS

The high rates of sunburn, the elevated personal UVR measured and the clearly insufficient sun protection practices followed during rock climbing together with unsatisfactory attitudes towards tanning reveal the need to develop explicit sun protection campaigns and educational strategies to reduce the risk of skin cancer among the athletes studied.

Ultraviolet exposure of competitors during a Tokyo Olympic Sailing Regatta Test Event

BACKGROUND

Overexposure to sunlight is the main cause of skin cancer. Photoprotection practices and sunburn play a crucial role in skin cancer prevention.

OBJECTIVES

This study aimed to quantify the risk of sun exposure and to evaluate photoprotection practices in Spanish sailors during Olympic competitions.

METHODS

Solar daily ultraviolet (UV) radiation cycle, personal UV dosimetry, photoprotection practices and sunburn checking were followed during three consecutive days of competition among sailors from the Spanish Olympic Sailing Team during a Tokyo Olympic Regatta Test Event.

RESULTS

A total of 13 sailors (7 women), with mean age of 27.6 ± 4.7 years and sports experience of 17.7 ± 5.4 years, were studied. The most common phototypes were type III (53.8%) and type II (38.5%). The rate of sunburn checked was high (46.2%). The mean daily personal UV exposure received was 761.0 ± 263.6 J/m² , 3.0 ± 1.1 minimal erythemal dose and 7.6 ± 2.6 standard erythemal dose, seven times greater than the maximum permissible UV light exposure values for an 8 h working day. The use of a T-shirt was the most common practice (94.2%), followed by the use of shade (50.2%), hat/cap (44.0%), sunglasses (26.1%) and sunscreen (11.8%).

CONCLUSIONS

Olympic sailor's studies presented high levels of UV radiation received, high rate of sunburn and insufficient adherence to sun-protective behaviours (especially, to use of sunscreen) to prevent sunburn, the main cause of skin cancer. Sport Federations should develop educational campaigns addressing sun-related exposure habits and photoprotection behaviours to reduce the risk of skin cancer among these athletes.

Sun Protection Behaviour and Sunburns in Spanish Cyclists

Sunburn caused by overexposure to ultraviolet radiation is the main cause of preventable skin cancer. This study aimed to describe the sun protection habits and rate of sunburns associated with the practice of cycling and to identify predictive factors of sunburn among cyclists. A descriptive observational study based on online surveys was conducted. Recruitment of participants was conducted through the Andalusian Cycling Federation (Spain). A questionnaire on behaviour, attitudes, and knowledge related to sun exposure was used. A bivariate analysis was carried out with sunburn episodes during the previous year as outcome variable, and a multivariate logistic regression model was built. Of the 1018 surveys returned, 87.6% were answered by men, mean age was 41.8 years (SD: 11.0), and 37.6% of the participants had phototype I or II. Sunburns during the previous year were reported by 45.6% (95% CI: 42.5-48.7) of the respondents. Sunscreen use was reported by 39.2%, and 61.0% did not examine their skin regularly despite the fact that 34 subjects (3.4%) reported a personal history of skin cancer. The multivariate logistic regression analysis showed that there was a negative correlation between episodes of sunburn and age, phototypes I-II, more than 2 h of sun exposure, and inconsistent use of sunscreen. Cyclists have high rates of sunburns and thus constitute a high-risk group for developing skin cancer. Educational interventions specifically aimed at this group of athletes would improve sun protection knowledge and practices, particularly the use of sunscreen.

Probing Different Approaches in Ultraviolet Radiation Personal Dosimetry - Ball Sports and Visiting Parks

Solar ultraviolet radiation (UVR) continues to be a decisive influencing factor for skin health. Besides acute damage (e.g. erythema), chronic light damage is of particular relevance. Skin cancer can develop on the basis of this light damage. Knowledge about irradiation is crucial for the choice of preventive measures, but has so far been incomplete in many occupational and leisure activities. Often a methodological problem in study design is the cause. Here we report on the clarification of two issues. First, further values are to be determined on the way to a comprehensive exposure register of leisure-related activities. Furthermore, it is to be determined to what extent the measurement setting can have an influence on the measurement campaigns. For long-term measurements, football referees were equipped with dosimeters over several months, selective measurements during visits to parks were carried out by on-site recruitment of test persons. It turned out that the choice of method also depends on the expected compliance of the test persons. Long-term measurements of specific activities such as playing football are particularly suitable for observing the course of UV exposure over the year and generating resilient mean values. Point measurements such as visits to parks can also do this if there are enough such events spread over the year. However, they are particularly suitable for such on-site campaigns, as they may be combined with awareness campaigns of the issue of skin cancer. They also allow many measurements to be taken at the same time in one place. Both playing football and visiting parks are associated with high levels of radiation, so specific prevention concepts need to be developed. We were able to determine that the sunburn dose for light skin types was reached or exceeded for both of the investigated activities.

Wearable ultraviolet radiation sensors for research and personal use

Skin cancers are strongly linked to personal exposure to ultraviolet (UV) radiation, yet UV exposure is also the most preventable risk factor. People are exposed to UV rays when they engage in outdoor activities, particularly exercise, which is an important health behavior. Thus, researchers and the general public have shown increasing interest in measuring UV exposure using wearable sensors during outdoor physical activity. However, minimal research exists at the intersection of UV sensors, personal exposure, adaptive behavior due to exposures, and risk of skin damage. Recent years have seen an influx of new consumer-based and research-based UV-sensing technologies with wide-ranging form factors and purposes to fill this research gap, yet a thorough review of available sensors for specific purposes does not exist. Hence, the overall goal of this state-of-the-art review is to synthesize the current academic and gray literature surrounding personal UV-sensing technologies. Peer-reviewed journal articles and "gray literature," such as working papers, manuals, and UV sensor websites, were reviewed, assessing attributes of UV wearables marketed for research use, personal use, or both. Overall, 13 wearable UV sensors are available for personal use and/or research applications. These sensors vary from electronic to photochromic, with large differences in price, data outputs, accuracy, and precision. Recommendations are provided for which sensors are most suitable for various types of research or public use. Notably, the review findings will help guide researchers in future studies assessing UV exposure during physical activity.

Photoprotection in Outdoor Sports: A Review of the Literature and Recommendations to Reduce Risk Among Athletes

Solar exposure, for long hours and often at peak times with limited shade available, predisposes athletes to episodic sunburn and chronic damage, causing increased risk of precancerous lesions and skin cancer. Environmental factors and training intensity affect risk. Clothing provides good protection, but changing established "uniforms" may not be possible for reasons of practicality, safety, or simply custom. Although physical activity should be encouraged for its physical and mental benefits, risk of skin damage should be minimised. We review existing behaviours, skin cancer risk, and campaigns in the sporting population and highlight key recommendations to help sun protection practices become engrained in sports practice.

"Beach Lifeguards' Sun Exposure and Sun Protection in Spain"

BACKGROUND

Sunburn is the main avoidable cause of skin cancer. Beach lifeguards spend many hours exposed to the effects of solar radiation during their work day, precisely at times of the year when levels of solar irradiation are highest. The aim of this study is to quantify the risk to beach lifeguards of sun exposure.

METHODS

A descriptive cross-sectional study was carried out in the Western Costa del Sol, southern Spain, during the summer of 2018. The research subjects were recruited during a skin cancer prevention course for beach lifeguards. All participants were invited to complete a questionnaire on their habits, attitudes, and knowledge related to sun exposure. In addition, ten were specially monitored using personal dosimeters for three consecutive days, and the results were recorded in a photoprotection diary. A descriptive analysis (mean and standard deviation for the quantitative variables) was performed, and inter-group differences were evaluated using the Mann-Whitney U test.

RESULTS

Two hundred fifteen lifeguards completed the questionnaire, and 109 met the criteria for inclusion in this analysis. The mean age was 23.8 years (SD: 5.1), 78.0% were male, 71.5% were phototype III or IV (Fitzpatrick's phototype), and 77.1% had experienced at least one painful sunburn during the previous summer. The mean daily personal ultraviolet exposure per day, the minimal erythema dose, and the standard erythema dose, in J/m2, were 634.7 [standard deviation (SD): 356.2], 2.5 (SD: 1.4) and 6.35 (SD: 3.6), respectively.

CONCLUSION

Beach lifeguards receive very high doses of solar radiation during the work day and experience correspondingly high rates of sunburn. Intervention strategies to modify their sun exposure behavior and working environment are necessary to reduce the risk of skin cancer for these workers and to promote early diagnosis of the disease.

Sun-related behaviors, attitudes and knowledge among paralympic sailors

BACKGROUND

Overexposure to sunlight is the main cause of skin cancer. Outdoor sports increased sun exposure times. Sun protection behaviors and attitudes are utmost importance to reduce sun exposure.

AIMS

To evaluate sun exposure habits, sun protection practices, and sun-related attitudes and knowledge among paralympic sailors.

METHODS

This descriptive observational study analysed the answers of a validated self-reported questionnaire of habits, attitudes and knowledge related to sun exposure and skin cancer completed by 56 elite sailors with disabilities from 19 countries which taking part in 2019 Para World Sailing Championships.

RESULTS

Three in four (76.8%) participants reported a history of sunburn in the previous season. Overall, participants showed an average for sport practice per week of 8.0 h (SD: 4.9). Participants reported a low adherence to sun protection practice, with the exception of using sunglasses (85.7%), sunscreen (83.9%) and hat (75%), having a very low rate (28.6%) of avoidance of midday sun and an inadequate sunscreen reapplication (33.9% reported "do not reapply" and 16.1% "reapply every one or 2 h"). Although 82.1% of participants reported to be worried about can get skin cancer out of the sun, they also presented excessive sun tanning attitudes (42.9% likes sunbathing and 57.1% sunbathing makes them feel well). The average score for sun-related knowledge was low (62.1 out 100 points; SD: 13.6).

CONCLUSIONS

Awareness campaigns on sun risk are needed specifically directed at this target group, in order to improve their sun protection habits and reduce the rates of sunburn associated with sports practice.

Measured UV Exposures of Ironman, Sprint and Olympic-Distance Triathlon Competitors

Triathletes present an extreme case of modelled behaviour in outdoor sport that favours enhanced exposure to solar ultraviolet radiation. This research presents personal solar ultraviolet exposures, measured using all-weather polysulphone film dosimeters, to triathletes during the distinct swimming, cycling and running stages of competitive Sprint, Olympic and Ironman events conducted within Australia and New Zealand. Measurements of exposure are made for each triathlon stage using film dosimeters fixed at a single site to the headwear of competing triathletes. Exposures are expressed relative to the local ambient and as absolute calibrated erythemally effective values across a total of eight triathlon courses (two Ironman, one half Ironman, one Olympic-distance, and four Sprint events). Competitor exposure results during training are also presented. Exposures range from between 0.2 to 6.8 SED/h (SED: standard erythema dose) depending upon the time of year, the local time of each event and cloud conditions. Cycle stage exposures can exceed 20 SED and represent the highest exposure fraction of any triathlon (average = 32%). The next highest stage exposure occurred during the swim (average = 28%), followed by the run (average = 26%). During an Ironman, personal competitor exposures exceed 30 SED, making triathlon a sporting discipline with potentially the highest personal ultraviolet exposure risk.

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.

Biologically effective solar ultraviolet exposures and the potential skin cancer risk for individual gold medalists of the 2020 Tokyo Summer Olympic Games

Personal solar ultraviolet radiation exposure models were developed for 144 Olympic events scheduled outdoors from across the 33 sport disciplines that will compete in Tokyo between 24 July and 9 August 2020. Ambient exposure models were developed from existing atmospheric parameters measured over Tokyo (35.7°N 139.7°E) and were used to weight erythemally effective solar ultraviolet exposure to gold medalists, taking into account body posture and expected protection by competitor's clothing which was assessed in comparison to respective medalists of the 2016 Rio Olympics. Individual exposure models consider the ultraviolet surface albedo (lawn, concrete, water or sand) and timing of daily events held within Olympic venues. Exposure assessments are presented, including assessments of all preliminary rounds and qualifiers. Within scheduled outdoor events, we award first place (representing the highest and most harmful UV exposure) to the women's tennis singles (1680 J/m²), second to men's golf (1530 J/m²) and third to the men's cycling road race (941 J/m²) for the highest expected erythemally effective solar ultraviolet radiation exposures of the 2020 Tokyo Games. The highest expected solar ultraviolet exposures for nations expected to win greater than three gold medals among the outdoor events were found to occur in athletes from Kenya followed closely by the United States and Hungary. Gold medalists from South Korea were found to demonstrate the highest level of sun protection due to clothing at the 2016 Rio Games, and are thus expected to receive the greatest relative reduction in erythemally effective exposure during the 2020 Tokyo Games.

Sun exposure of indoor workers in the UK – survey on the time spent outdoors

A lifestyle questionnaire has been used to obtain information on the time spent outdoors by indoor workers that could be used in combination with dosimetry studies in smaller targeted groups to quantify UV exposure for health risk/benefit analysis.

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.

Contribution of sun exposure to the vitamin D dose received by various groups of the Spanish population

Although the harmful effects of excessive exposure to solar ultraviolet (UV) radiation are well known, the recommended dose of UV radiation is beneficial for the synthesis of vitamin D by the skin, in addition to being useful in the treatment of various illnesses and mental problems. Numerous studies have shown that vitamin D performs important functions in the human organism, such as absorbing calcium and phosphorous and contributing to the immune system, among others. Several studies have found that a high percentage of various groups of the Spanish population suffer from vitamin D deficiency, and since very few natural foods contain vitamin D, it was considered important to determine whether groups such as schoolchildren, outdoor workers and athletes, receive enough solar radiation to produce adequate levels of vitamin D in their daily activities. It was found that the amount of vitamin D (in IU) produced by personal effective solar UV doses could exceed the recommended dose of 1000IU/day in spring and summer, while the winter estimate (about 220IU/day) is only one quarter of the recommended dose. These results suggest that most people would not receive the recommended daily vitamin D dose in winter from exposure to solar UV radiation, the main source of vitamin D.

Maximum Incident Erythemally Effective UV Exposure Received by Construction Workers, in Valencia, Spain

This article analyzes the influence of Ultraviolet Erythematic Radiation (UVER) dose received by construction workers in Valencia highlighting the upper limit of the dose received for a worker in different periods of a year. Building construction usually implies workers to stand for several hours outdoors while working until roof top is finished. In Valencia, construction carried out near the coastline has been very intense in the last few years with the construction of a great amount of summer flats. This article focuses on the maximum values UVER can reach in different seasons of the year for cities with similar latitude to Valencia (39°28'N, 0°22'W), as an important way of warning construction workers about the necessity of taking preventive actions. Viospor dosimeters placed on a mannequin have been used in this study. The measurements took place between 2012 December and 2013 July.

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.

Ultraviolet Erythematic Radiation dose received by golfers in winter, in Valencia

This article analyzes Ultraviolet Erythematic Radiation (UVER) dose received by several golf players in winter in Valencia. Playing golf involves spending several hours outdoors because of the length of golf matches and training. Moreover, in Valencia there are many golf players coming from northern Europe, with a phototype very sensitive (I-II). For that reason, these people have an increasing risk while playing. This article shows that harmful effects coming from UVER radiation may occur not only in summer time but also in winter, especially at these latitudes. VioSpor dosimeters have been used to develop this analysis over several golf players on January 2013 between 10:00 h and 15:00 h, local time.

Ultraviolet radiation and the athlete: risk, sun safety, and barriers to implementation of protective strategies

Ultraviolet (UV) radiation plays a pivotal role in the development of both melanoma and non-melanoma skin cancers. Numerous factors potentially place athletes at high risk for developing these cancers. Various prevention strategies ameliorate this risk, including avoiding sun exposure during peak UV exposure hours, applying sunscreen with a sun protection factor of 30 or above before participating in outdoor sports, wearing hats and sunglasses, and reducing exposure with long pants and long-sleeve shirts. The literature, however, cites several barriers to these prevention approaches, including sports' competition rules, the lack of availability of sunscreen, and the lack of information about sun safety behaviors. Sun safety education programs prove effective in getting athletes to participate in prevention strategies. This article reviews the effect of UV radiation on athletes' skin and provides sports medicine clinicians with suggestions to improve the sun safety behaviors of their athletes.

Personal UV exposure for different outdoor sports

The aim of this paper is to measure UV exposure for three groups of amateur athletes in their training/recreational schedules using VioSpor personal dosimeters and we found that two of these groups exceeded the international UV threshold level for non-sun-adapted Mediterranean skin.

Doses of erythemal ultraviolet radiation observed in Brazil

Non-melanoma skin cancer represents a quarter of the new cancer cases detected in Brazil. Despite the importance of this issue to public health, there are deficits in knowledge on the local UV radiation levels among physicians. In this work, we evaluate a set of daily erythemal UV doses measured in different Brazilian locations. Very high erythemal UV doses that often exceeded safe amounts were observed over almost the whole year, even during the time interval usually recommended as safe (before 10:00 h and after 16:00 h). These findings will hopefully enable foreign tourists, dermatologists, and decision-makers to implement new measures for solar protection according to South American standards.

Melanoma induction by ultraviolet A but not ultraviolet B radiation requires melanin pigment

Malignant melanoma of the skin (CMM) is associated with ultraviolet radiation exposure, but the mechanisms and even the wavelengths responsible are unclear. Here we use a mammalian model to investigate melanoma formed in response to precise spectrally defined ultraviolet wavelengths and biologically relevant doses. We show that melanoma induction by ultraviolet A (320-400 nm) requires the presence of melanin pigment and is associated with oxidative DNA damage within melanocytes. In contrast, ultraviolet B radiation (280-320 nm) initiates melanoma in a pigment-independent manner associated with direct ultraviolet B DNA damage. Thus, we identified two ultraviolet wavelength-dependent pathways for the induction of CMM and describe an unexpected and significant role for melanin within the melanocyte in melanomagenesis.

Solar UV exposure of children in a summer school in Valencia, Spain

Ultraviolet (UV) exposure is the major environmental factor involved in the development of skin cancers and occurs mainly during outdoor activities. During summer schools, children receive regular and significant solar ultraviolet erythemal radiation (UVER) while practising outdoor activities. Personal dosimeters (VioSpor) were attached to the shoulders of schoolchildren and used to quantify their exposure to UVER. The study took place in Valencia, Spain, during July 2008, with three age groups (7-8, 9-10 and 11-12 years old) and involved about 15 schoolchildren. The median (25, 75 percentiles) twice-daily UV exposure values for all groups was 5.49 (3.59, 8.00) standard erythemal doses (SEDs), where 1 SED is defined as effective 100 Jm(-2) when weighted with the CIE erythemal response function. Exposure ratio (ER) is defined as the ratio between the personal dose on a selected body site and the corresponding ambient dose received on a horizontal plane during the same exposure period. The median (25, 75 percentiles) ER value for all groups in the study was 5.9% (4.1, 8.7).

The eicosanoid response to high dose UVR exposure of individuals prone and resistant to sunburn

High personal UVR doses can be gained during leisure activities, causing intense self-resolving inflammation (sunburn) of unprotected skin. UVR activates release of membrane fatty acids and upregulates their metabolism by cyclooxygenases (COX) and lipoxygenases (LOX) to different eicosanoids. While COX-derived prostaglandin (PG)E(2) is a potent mediator of sunburn vasodilatation, LOX-derived 15-hydroxyeicosatetraenoic acid (HETE) and its lipoxin metabolites may contribute to sunburn limitation. We explored the relationships between expression of these lipid mediators and the clinical and histological outcomes, comparing responses of individuals prone and more resistant to sunburn. An acute UVR exposure of 12 SED (standard erythema dose) was applied to buttock skin of 32 white Caucasians (n = 16 phototype I/II, n = 16 phototype III/IV), and over the subsequent 72 h assessments were made of skin erythema, immunohistochemical expression of leukocyte markers, COX-2, 12-LOX, 15-LOX and nitric oxide synthase (NOS), and eicosanoid levels by LC/ESI-MS/MS. Evidence of a significant inflammatory response was seen earlier in phototype I/II with regard to expression of erythema (4 h, p < 0.001), neutrophil infiltration (24 h, p = 0.01), epidermal COX-2 (24 h, p < 0.05) and 12-LOX (24 h, p < 0.01), and dermal eNOS (24 h, p < 0.05) proteins, although CD3+ lymphocyte infiltration showed an earlier increase in phototype III/IV (24 h, p < 0.05). Although erythema was equivalent at 72 h in both groups, phototype I/II showed higher PGE(2) accompanied by elevated 15-HETE, and a strong positive correlation was seen between these mediators (n = 18, r = 0.805, p = 0.0001). Hence anti-inflammatory eicosanoid 15-HETE may temper the pro-inflammatory milieu in sunburn, having greater influence in those prone to sunburn than those more resistant, given the same high UVR exposure conditions.

Interferon-γ links ultraviolet radiation to melanomagenesis in mice

Cutaneous malignant melanoma is a highly aggressive and frequently chemoresistant cancer, whose incidence continues to rise. Epidemiological studies reveal that the major etiological melanoma risk factor is ultraviolet (UV) solar radiation, with the highest risk associated with intermittent burning doses, especially during childhood1,2. We have experimentally validated these epidemiological findings using the hepatocyte growth factor/scatter factor (HGF/SF) transgenic mouse model, which develops lesions in stages highly reminiscent of human melanoma with respect to biological, genetic and etiologic criteria, but only when irradiated as neonatal pups with UVB, not UVA3,4. However, mechanisms underlying UVB-initiated, neonatal-specific melanomagenesis remain largely unknown. Here we introduce a mouse model permitting fluorescence-aided melanocyte imaging and isolation following in vivo UV irradiation. We use expression profiling to show that activated neonatal skin melanocytes isolated following a melanomagenic UVB dose bear a distinct, persistent interferon response signature, including genes associated with immunoevasion. UVB-induced melanocyte activation, characterized by aberrant growth and migration, was abolished by antibody-mediated systemic blockade of interferon-γ (IFN-γ), but not type-I interferons. IFN-γ was produced by macrophages recruited to neonatal skin by UVB-induced ligands to the chemokine receptor Ccr2. Admixed recruited skin macrophages enhanced transplanted melanoma growth by inhibiting apoptosis; notably, IFN-γ blockade abolished macrophage-enhanced melanoma growth and survival. IFN-γ-producing macrophages were also identified in 70% of human melanomas examined. Our data reveal an unanticipated role for IFN-γ in promoting melanocytic cell survival/immunoevasion, and suggest that IFN-γ-R signaling represents a novel therapeutic melanoma target.