Significant trends of ultraviolet radiation (UVR) have been reported at limited European sites due to changing atmospheric conditions, such as cloudiness. Whether these findings are applicable to larger areas or even the entire continent remains unclear. In a unique comparison, we analyzed measurements of erythemally weighted daily ambient radiant exposure from 40 European locations, covering the period from 2013 to 2022. At 26 locations annual means increases statistically significantly with a median of + 1.2

Solar particle events (SPEs) are short-lived bursts of high-energy particles from the solar atmosphere and are widely recognized as posing significant economic risks to modern society. Most SPEs are relatively weak and have minor impacts on the Earth's environment, but historic records contain much stronger SPEs which have the potential to alter atmospheric chemistry, impacting climate and biological life. The impacts of such strong SPEs would be far more severe when the Earth's protective geomagnetic field is weak, such as during past geomagnetic excursions or reversals. Here, we model the impacts of an extreme SPE under different geomagnetic field strengths, focusing on changes in atmospheric chemistry and surface radiation using the atmosphere-ocean-chemistry-climate model SOCOL3-MPIOM and the radiation transfer model LibRadtran. Under current geomagnetic conditions, an extreme SPE would increase NOx concentrations in the polar stratosphere and mesosphere, causing reductions in extratropical stratospheric ozone lasting for about a year. In contrast, with no geomagnetic field, there would be a substantial increase in NOx throughout the entire atmosphere, resulting in severe stratospheric ozone depletion for several years. The resulting ground-level ultraviolet (UV) radiation would remain elevated for up to 6 y, leading to increases in UV index up to 20 to 25% and solar-induced DNA damage rates by 40 to 50%. The potential evolutionary impacts of past extreme SPEs remain an important question, while the risks they pose to human health in modern conditions continue to be underestimated.

This study analyses the variability and trends of ultraviolet-B (UV-B, wavelength 280–320 nm) radiation that can cause DNA damage. The variability and trends caused by climate change due to enhanced greenhouse gas (GHG) concentrations. The analysis is based on DNA-active irradiance, total ozone, total cloud cover, and surface albedo calculations with the European Centre for Medium-Range Weather Forecasts – Hamburg (ECHAM)/Modular Earth Submodel System (MESSy) Atmospheric Chemistry (EMAC) chemistry–climate model (CCM) free-running simulations following the RCP 6.0 climate scenario for the period 1960–2100. The model output is evaluated with DNA-active irradiance ground-based measurements, satellite SBUV (v8.7) total-ozone measurements, and satellite MODerate-resolution Imaging Spectroradiometer (MODIS) Terra cloud cover data. The results show that the model reproduces the observed variability and change in total ozone, DNA-active irradiance, and cloud cover for the period 2000–2018 quite well according to the statistical comparisons. Between 50∘ N–50∘ S, the DNA-damaging UV radiation is expected to decrease until 2050 and to increase thereafter, as was shown previously by Eleftheratos et al. (2020). This change is associated with decreases in the model total cloud cover and negative trends in total ozone after about 2050 due to increasing GHGs. The new study confirms the previous work by adding more stations over low latitudes and mid-latitudes (13 instead of 5 stations). In addition, we include estimates from high-latitude stations with long-term measurements of UV irradiance (three stations in the northern high latitudes and four stations in the southern high latitudes greater than 55∘). In contrast to the predictions for 50∘ N–50∘ S, it is shown that DNA-active irradiance will continue to decrease after the year 2050 over high latitudes because of upward ozone trends. At latitudes poleward of 55∘ N, we estimate that DNA-active irradiance will decrease by 8.2 %±3.8 % from 2050 to 2100. Similarly, at latitudes poleward of 55∘ S, DNA-active irradiance will decrease by 4.8 % ± 2.9 % after 2050. The results for the high latitudes refer to the summer period and not to the seasons when ozone depletion occurs, i.e. in late winter and spring. The contributions of ozone, cloud, and albedo trends to the DNA-active irradiance trends are estimated and discussed.

The Montreal Protocol on Substances that Deplete the Ozone Layer has been hailed as the most successful environmental treaty ever ( https://www.unenvironment.org/news-and-stories/story/montreal-protocol-triumph-treaty ). Yet, although our main concern about ozone depletion is the subsequent increase in harmful solar UV radiation at the Earth's surface, no studies to date have demonstrated its effectiveness in that regard. Here we use long-term UV Index (UVI) data derived from high-quality UV spectroradiometer measurements to demonstrate its success in curbing increases in UV radiation. Without this landmark agreement, UVI values would have increased at mid-latitude locations by approximately 20% between the early 1990s and today and would approximately quadruple at mid-latitudes by 2100. In contrast, an analysis of UVI data from multiple clean-air sites shows that maximum daily UVI values have remained essentially constant over the last ~20 years in all seasons, and may even have decreased slightly in the southern hemisphere, especially in Antarctica, where effects of ozone depletion were larger. Reconstructions of the UVI from total ozone data show evidence of increasing UVI levels in the 1980s, but unfortunately, there are no high-quality UV measurements available prior to the early 1990s to confirm these increases with direct observations.

Ultraviolet (UV) radiation has affected life at least since the first life forms moved out of the seas and crawled onto the land. Therefore, one might assume that evolution has adapted to natural UV radiation. However, evolution is mostly concerned with the propagation of the genetic code, not with a long, happy, and fulfilling life. Because rickets is bad for a woman giving birth, the beneficial effects of UV-radiation outweigh the adverse effects like aged skin and skin tumors of various grades of malignancy that usually only afflict us at older age. Anthropogenic damage to the stratospheric ozone layer and frighteningly high rates of melanoma skin cancer in the light-skinned descendants of British settlers in Australia piqued interest in the health impacts of UV radiation. A changing cultural perception of the beauty of tanned versus light skin and commercial interests in selling UV-emitting devices such as tanning booths caught public health experts off-guard. Counseling and health communication are extremely difficult when dealing with a "natural" risk factor, especially when this risk factor cannot (and should not) be completely avoided. How much is too much for whom or for which skin type? How even measure "much"? Is it the (cumulative) dose or the dose rate that matters most? Or should we even construct a more complex metric such as the cumulative dose above a certain dose rate threshold? We find there are still many open questions, and we are glad that this special issue offered us the opportunity to present many interesting aspects of this important topic.

In a recent study, melanoma incidence rates for Austrian inhabitants living at higher altitudes were found to increase by as much as 30% per 100 m altitude. This strong increase cannot simply be explained by the known increase of erythemally-weighted irradiance with altitude, which ranges between 0.5% and 4% per 100 m. We assume that the discrepancy is partially explainable by upwelling UV radiation; e.g., reflected by snow-covered surfaces. Therefore, we present an approach where the human UV exposure is derived by integrating incident radiation over the 3D geometry of a human body, which enables us to take upwelling radiation into account. Calculating upwelling and downwelling radiance with a radiative transfer model for a snow-free valley and for snow-covered mountain terrain (with albedo of 0.6) yields an increase in UV exposure by 10% per 100 m altitude. The results imply that upwelling radiation plays a significant role in the increase of melanoma incidence with altitude.

Recreational sun exposure accounts for a large number of acute and chronic dermatological diseases, including skin cancer. This study aimed at estimating the one-year prevalence of sun exposure and skin health-associated knowledge and attitudes among Austrian citizens. The population-based UVSkinRisk survey investigated a representative sample of Austrian adults using a structured questionnaire. In total, 1500 study subjects (median age 33.0 years, 50.5% females) participated in this questionnaire survey. Among study participants, prevalence of sun exposure was 47%, with slightly higher rates in males (48%) compared to females (46%). Younger age, lower professional category, darker skin type, motives to tan, sunbed use, sunburn, and outdoor sport activity increased the odds for prevalent sun exposure. This is the first population-based study evaluating the prevailing sun exposure and recreational habits influencing skin health among Austrian citizens. Despite public media campaigns educating on the harmful effects of sunlight exposure, we found a high prevalence of self-reported sunlight exposure. The results suggest that multifaceted socio-cultural characteristics stimulate recreational sun exposure and tanning habits. Communicating individualized Public (Skin) Health messages might be the key to prevent photo-induced skin health hazards in light-skinned populations. The practical and theoretical implications of these findings are discussed.

Ultra-Violet (UV) radiation covers the spectrum of wavelengths from 100 to 400 nm. The potency and biological activity for a variety of endpoints differ by wavelength. For monitoring and communication purposes, different UV action spectra have been developed. These spectra use different weighting functions. The action spectrum for erythemal dose is the most widely used one. This erythemal dose per time or dose-rate has been further simplified into a "UV index". Following this example, in our review we use the term "index" or (plural) "indices" in a more general description for all simplified single-value measures for any biologically effective UV dose, e.g., for human non-melanoma skin cancer and for previtamin D production rate. Ongoing discussion about the existence of an increased melanoma risk due to UV-A exposure underscores the uncertainties inherent in current weighting functions. Thus, we performed an online literature search to review the data basis for these indices, to understand their relevance for an individual, and to assess the applicability of the indices for a range of exposure scenarios. Even for natural (solar) UV, the spectral composition varies spatially and temporally. Artificial UV sources and personal protection introduce further variation to the spectral composition. Many biological effects are proposed for UV radiation. Only few endpoints have been studied sufficiently to estimate a reliable index. Weighting functions for chronic effects and most importantly for cancer endpoints have been developed in animal models, and often for proxy endpoints only. Epidemiological studies on biological effects of UV radiation should not only depend on single-value weighted UV dose estimates (indexes) but should strive for a more detailed description of the individual exposure. A better understanding of the adverse and beneficial effects of UV radiation by wavelength would also improve medical counseling and health communication regarding individual health-supportive behavior.

Recreational sunbed use accounts for the main non-solar source of exposure to ultraviolet radiation in fair-skinned Western populations. Indoor tanning is associated with increased risks for acute and chronic dermatological diseases. The current community-based study assessed the one-year prevalence of sunbed use and associated skin health habits among a representative, gender-balanced sample of 1500 Austrian citizens. Overall one-year prevalence of sunbed use was 8.9% (95% confidence interval (CI) 7.5%–10.4%), with slightly higher prevalence in females (9.2%, 95% CI 7.3%–11.2%) compared to males (8.6%, 95% CI 6.7%–10.6%). Factors predicting sunbed use were younger age (by trend decreasing with older age), place of living, smoking, skin type (by trend increasing with darker skin), sun exposure, motives to tan, and use of UV-free tanning products. Despite media campaigns on the harmful effects of excessive sunlight and sunbed exposure, we found a high prevalence of self-reported sunbed use among Austrian citizens. From a Public (Skin) Health perspective, the current research extends the understanding of prevailing leisure time skin health habits in adding data on prevalence of sunbed use in the general Austrian population.

Individual skin health attitudes are influenced by various factors, including public education campaigns, mass media, family, and friends. Evidence-based, educative information materials assist communication and decision-making in doctor-patient interactions. The present study aims at assessing the prevailing use of skin health information material and sources and their impact on skin health knowledge, motives to tan, and sun protection. We conducted a questionnaire survey among a representative sample of Austrian residents. Print media and television were perceived as the two most relevant sources for skin health information, whereas the source physician was ranked third. Picking the information source physician increased participants' skin health knowledge (p = 0.025) and sun-protective behavior (p < 0.001). The study results highlight the demand for targeted health messages to attain lifestyle changes towards photo-protective habits. Providing resources that encourage pro-active counseling in every-day doctor-patient communication could increase skin health knowledge and sun-protective behavior, and thus, curb the rise in skin cancer incidence rates.

PurposeLifetime risk for melanoma skin cancer is enlarged by sunlight exposure and reduced by sun protection. Austrian melanoma incidence and mortality rates are constantly rising with higher rates in males. Thus, we aimed at investigating gender-specific recreational sun exposure habits among the Austrian population.MethodsWe conducted a telephone survey among 1500 adults (50.5% females) representing sociodemographic characteristics of the Austrian population. Using a structured questionnaire, we studied gender-specific sun exposure-related knowledge, motives to tan, and behavior.ResultsOverall, using sunscreen, wearing sunglasses, and seeking shade were among the three most frequent sun safe measures. Basic skin health knowledge and tanning motives were similar among genders, although females protected themselves more. In general, sunburn occurrence (odds ratio [OR] = 1.4, 95% confidence interval [CI] = 1.0-1.8), skin type IV (OR = 2.4, 95% CI = 1.3-4.5), ex-/non-smoking (OR = 1.4-1.6, 95% CI = 1.0-2.1), low motives to tan (both OR = 1.3, 95% CI = 1.0-1.7), no outdoor sport (OR = 1.3, 95% CI = 1.0-1.7), all P < 0.05, as well as the use of sunscreen with lower SPF values (OR = 1.0-3.0, 95% CI = 1.4-4.3) and male gender (OR = 1.6, 95% CI = 1.2-2.0), both P < 0.001, increased the odds of practicing low sun protection.ConclusionThe results of this investigation suggest considering gender specificity when planning Public (Skin) Health-related educative campaigns and programs, for example, by highlighting the appearance-related benefits of sun light avoidance.

Annual solar ultraviolet radiation (UVR) is mostly determined by latitude and altitude. Over the last decades, increasing UVR ground levels have been observed. Exposure to UVR is associated with a life-time risk to develop melanoma, a malign skin cancer. Thus, we hypothesized that melanoma incidence in Austria is associated with altitude of place of living and time of diagnosis. We investigated this hypothesis in an ecological study by district and year for Austrian melanoma incidence (1990–2010) and mortality (1970–2011) data. As expected, incidence rates increased with altitude (about 2% per 10 m) and year (about 2%). Additionally, melanoma incidence rates were about 50% higher in urban than in rural districts. In contrast, mortality rates decreased with altitude (for males: 0.4% per 10 m, for women: 0.7% per 10 m, respectively). The observed discrepancy between incidence and mortality data could partly be explained by melanoma diagnosis at earlier tumor stage in districts with higher altitude. Possible reasons for this finding include higher awareness of patients, better diagnostic performance of medical professionals working at higher altitudes, or slower tumor growth due to protective effects of sun light-associated vitamin D synthesis.

Connectedness to nature (CN) influences motivation to have contact with outdoor natural environments. Spending leisure time in natural environments is beneficial for human health and well-being. Besides these positive effects, health risks of open-air activities are mainly related to unprotected sun light exposure-associated acute and chronic skin hazards. Thus, we conducted a cross-sectional, representative telephone survey among Austrian residents to study the association of perceived CN level with sun-exposure knowledge, tanning habits, and sun protective behaviour. In total, 1,500 study subjects (50.5% females) participated in this questionnaire survey. Although knowledge about tanning and motives to tan were similar among genders, females performed more photoprotective measures and were more connected to nature (all p < 0.001) compared to males. Older age and outdoor sport were significant gender-independent predictor variables influencing perceived CN level. Additionally, level of education was relevant in male CN, whereas non-smoking and higher knowledge were predictive of female CN. This survey provides so far unreported empirical data on the relationship between nature connectedness and skin health-relevant recreational habits of Austrian residents. The findings suggest to integrate hitherto neglected gender-specific Public (Skin) Health promotion when counselling on the manifold health advantages of outdoor activities.

Continuous measurements of spectral UV according to the quality requirements of NDACC (Network for the Detection of Atmospheric Composition Change) as well as total ozone measurements are performed at Hoher Sonnblick since 1994. The uninterrupted dataset is among the longest in Europe, and unique because of the clean, undisturbed air at the high-altitude mountain observatory. Based on these data-series, long-term trends in surface UV levels are investigated for the time period 1994-2011, accounting for several wavelengths, sub-periods, solar zenith angles and different levels of cloudiness, using nonparametric trend tests and regression models, further expanding and extending an existing analysis with the newest data sets. Trends that are identified are tested for significance at various levels and are examined in detail to identify changes due to trends in e. g. ozone, albedo, sunshine duration and cloudiness, which could, in the course of a changing global climate, significantly contribute to changing surface UV levels and consequently potential risks to the biosphere. Throughout the year, significant upward trends are found at wavelengths of 315 nm and longer, ranging from about +10 %/dec up to +14 %/dec for all-sky conditions, depending on solar zenith angle. Trend estimates at wavelengths that are heavily affected by ozone absorption are smaller and less significant. Seasonally, the largest trends are found during winter and spring. Total ozone has significantly increased by about +2 %/dec since 1997 and therefore cannot explain these significant increases. They are rather attributed to decreases in total cloud cover and aerosol optical depth and increased sunshine duration over the investigated period.

Die Inzidenz von malignem Melanom ist in Österreich wie in vielen anderen Ländern in den letzten Jahrzehnten gestiegen. Neben verbesserter Diagnostik und Meldedisziplin sind für den Anstieg sowohl Änderungen im (Freizeit-)Verhalten als auch ein Anstieg der UV-Belastung als Folge der Zerstörung der stratosphärischen Ozonschicht (bis etwa zur Jahrtausendwende) verantwortlich.

Objectives: Melanoma incidence increased in Austria in the last decades. Solar UV radiation increased until recently because of the damage to the ozone layer. With the restoration of the ozone layer UV radiation is predicted to decline again. If the increase in melanoma incidence were mostly due to the change in natural UV radiation we might expect declining incidence rates in the future. Exposure data: We assessed trends in UV annual cumulative doses at 9 fixed monitoring stations in Austria since 1961. There was strong inter-annual variation that was deemed not relevant for melanoma incidence. Apart from that, we observed an increase in annual cumulative UV dose of 1.2 kJ/m² per year consistently across stations. The only predictor of differences found between stations was the height above sea level with a gradient of 13.1 kJ/m² per 100 meter. Health data and methods: We obtained population data and melanoma incidences per 5-year age groups and gender for all 120 districts of Austria. We performed Poisson regression for each gender-age group with the gender-age specific population size as offset and year and height above sea level as predictor variables. Results: Averaged across strata melanoma incidence increased by 2% annually and by 20% per 100 m increase of height above sea level of the district. This fits well with the change in cumulative UV dose for these predictors. Effects were consistently stronger in younger age groups. Discussion and conclusions: Not only cumulative dose but also day-by day variability of UV radiation increased by year and by height above sea level with the strongest variation seen in summer. Since melanoma risk might be affected most strongly by peak exposures, for future scenarios not only cumulative average exposure but also variability and peak exposures would be of interest.

Series of daily erythemal UV-dose are reconstructed for the last 30 years of the 20th century in Austria and its changes during that period with respect to observed changes in total ozone and cloud cover discussed. The reconstruction method is based on the relationship between long-term global radiation and sunshine duration records and existing measurements of erythemal UV at several locations. Through comparison with different data sources efforts are made to assure high data quality for all input parameters. The results for reconstructed daily sums show high correlations (0.95-0.99) with observed values compared on a yearly and seasonal basis throughout the overlapping period 1998-2010. Assessed from the reconstructed data, long-term variability of erythemal UV daily dose for two time periods has been quantified (1977-1995, 1996-2010). Special emphasis is put on the investigation of changes in UV due to observed trends in clouds and sunshine duration in the Austrian Alpine regions during the last decades. The earlier period shows significant changes between +4.1 %/dec and +6.9 %/dec at six stations in Austria, mainly due to significant decreases in total ozone column of up to -3.7 %/dec. Positive significant trends of around +2%/dec are found in cloud and aerosol modification factors at most of stations along with observed positive trends in sunshine duration, being statistically significant at eastern and southern stations. In spite of ozone layer recovery since the mid 1990s, the latter period does not reveal any statistically significant changes in erythemal UV irradiation.

The aim of this study is to investigate the influence of the spatial resolution of a digital elevation map (DEM) on the three-dimensional (3-D) radiative transfer performance for both spectral ultraviolet (UV) irradiance and actinic flux at 305 nm. Model simulations were performed for clear sky conditions for three case studies: the first and second one using three sites in the Innsbruck area and the third one using three sites at the Sonnblick observatory and surrounding area. It was found that the DEM resolution may change the altitude at some locations by up to 500 m, resulting in changes in the sky obscured by the horizon of up to 15%. The geographical distribution of UV irradiance and actinic flux shows that with larger pixel size, uncertainties in UV irradiance and actinic flux determination of up to 100% are possible. These large changes in incident irradiance and actinic flux with changing pixel size are strongly connected to shading effects. The effect of the DEM pixel size on irradiance and actinic flux was studied at the six locations, and it was found that significant increases in irradiance and actinic flux with increasing DEM pixel size occurred at one valley location at high solar zenith angles in the Innsbruck area as well as for one steep valley location in the Sonnblick area. This increase in irradiance and actinic flux with increasing DEM resolution is most likely to be connected to shading effects affecting the reflections from the surroundings.

High-quality long-term records of spectral UV irradiance from the Network for the Detection of Atmospheric Composition Change-affiliated Bentham spectroradiometer at the high-mountain site Hoher Sonnblick (47.05° N, 12.95° E, 3,106 m above sea level) from the period 1997–2011 have been investigated for the existence of trends. Throughout the year, significant upward trends are found at wavelengths of 315 nm and longer. The magnitudes at 315 nm range from +9.3 ± 4.5 %/dec at 45° solar zenith angle (SZA) to +14.2 ± 3.7 %/dec at SZA 65° for all-sky conditions. The trend estimates at 305 nm are considerably smaller and less significant, yielding between +5.1 ± 6.5 and +7.9 ± 7.3 %/dec, depending on SZA. Seasonally, the largest trends are found during winter and spring. Total ozone has significantly increased by year-round +1.9 ± 1.3 %/dec since 1997 and therefore cannot explain these significant increases. They are rather attributed to decreases in total cloud cover and aerosol optical depth.