Impact Of Ultraviolet Radiation Research Articles

Study on the UV aging resistance of ZnO‐modified epoxy resin by experiments and MD simulation

AbstractThis study investigates the impact of zinc oxide nanoparticles on epoxy resin systems and the ultraviolet (UV) aging resistance of modified epoxy resin composites using molecular dynamics (MD) simulations and experimental methods. Initially, various epoxy resin cross‐linking models are established through MD simulations to understand the influence of different nano ZnO contents on resin modification, further validated by experiments. Subsequently, the UV radiation resistance of nano ZnO–epoxy resin composites is assessed by subjecting them to high‐intensity UV radiation equivalent to 3 years of natural environmental conditions, analyzing changes in tensile properties, impact performance, hardness, and glass transition temperature of epoxy resin before and after UV radiation exposure. The findings suggest that the addition of nano zinc oxide reduces the impact of UV radiation on epoxy resin, with optimal UV radiation resistance observed at a nano zinc oxide mass fraction of 0.3 wt%.

An overview of benefits and risks of chronic melanocortin-1 receptor activation.

The melanocortin-1 receptor (MC1R) is a G protein-coupled receptor that plays a pivotal role in human skin pigmentation, melanin synthesis, redox homeostasis and inflammation. Loss-of-function MC1R variants suppress G protein-coupled receptor coupling or cell surface expression leading to a decrease in adenyl cyclase activation and intracellular levels of cyclic adenosine monophosphate. Chronic activation of MC1R can occur in certain medical conditions such as Addison's disease and physiologic states such as pregnancy melasma. MC1R activation is more commonly caused by environmental exposure to ultraviolet (UV) radiation. Approved pharmacologic melanocortin agonists that activate MC1R signalling in a targeted manner or as a bystander effect have recently become available for erythropoietic protoporphyria, sexual desire disorders, monogenic obesity and syndromic obesity. Further, small peptide analogues of α-melanocortin-stimulating hormone, human MC1R selective agonists, are photoprotective, decreasing the adverse impact of UV radiation (a primary risk factor for skin cancer) and are being investigated as potential chemoprevention strategies. MC1R activation through induction of UV-protective skin pigmentation increased DNA repair, and control of aberrant cell growth may reduce the risk of melanoma but importantly does not prevent melanoma particularly in individuals with risk factors and regular skin examination remains critical in high-risk individuals.

Impact of Ultraviolet Radiation on the Aging Properties of PVC Films Doped by Tin(IV) Complexes

Impact of Ultraviolet Radiation on the Aging Properties of PVC Films Doped by Tin(IV) Complexes

Effect of electrophysical treatments on the storage life of potatoes and other vegetable crops

To prevent the progression of various infectious diseases, seed and planting material must undergo treatment with ultraviolet (UV) radiation at an intensity of 10-15 kilojoules. This necessitates studying the impact of UV radiation on products as they move in a flow along a conveyor belt. (Research purpose) The study aims to evaluate the feasibility of using ultraviolet radiation to improve the storage indicators of potato and other vegetable crops. It also assesses the technological parameters in both laboratory and production settings to ensure a reduction in contamination. (Materials and methods) To determine the optimal technological parameters of a machine for processing vegetable crops and potatoes before storage in the post-harvest processing system, an experimental installation was created and the electrophysical effects on storage quality indicators were examined. For the study, the most common vegetable crop varieties were selected, in particular, Lady Rosetta potato, Vitaminnaya-6 table carrot and Bordeaux 237 table beet. These crops are cultivated under various soil and climatic conditions across the Russian Federation. (Results and discussion) A methodology has been developed to assess the quality of seed material after the storage period, including the justification for the time interval, air mixture temperature parameters and ultraviolet radiation optical modes. The optimal parameters for processing potato tubers, carrots, and beets have been determined. The study examined the impact of ultraviolet exposure with established parameters on the disease development in carrot and beet crops, caused by the studied phytopathogenic microorganisms at temperatures of 2 and 25 degrees Celsius. (Conclusions) The indicators of the spread and development of infectious diseases in the studied vegetable crops show a decline trend when the translational speed of root crop movement is 0.7 meters per second, the interaxial distance between ultraviolet radiation sources is 0.1 meters, the distance from the sources to the roller surface of the conveyor belt is 0.05 meters, and a constant dose of ultraviolet exposure is applied.

Impact of ultraviolet aging on the composition and characteristics of multifunctional composite coatings

AbstractMultifunctional composite coatings exposed to environmental conditions are prone to aging and potential functional failure due to ultraviolet (UV) radiation. This study investigates the impact of UV radiation on the structure and properties of low infrared emissivity composite coatings, comprising ethylene propylene diene monomer (EPDM) as the matrix and antistatic carbon fiber (CF) and flaky floating aluminum powder as fillers. In addition to analyzing the photochemical degradation reactions of the composite coating under UV irradiation, the role of fillers in resisting UV aging is elucidated. The performance parameters examined include infrared (IR) emissivity, surface resistivity, mechanical properties, and dielectric properties. The results indicate that after UV aging, EPDM undergoes the most significant changes, leading to the formation of carbonyl groups. CFs experience mild UV aging and an increase in resistivity. Aluminum powder, on the other hand, remains largely unchanged after UV aging and its addition significantly reduces the UV aging rate of the composite coating, resulting in a low IR emissivity of as low as 0.2 after UV aging. Among them, Coating 4 exhibits the best overall performance after UV aging.Highlights The UV aging mechanism of EPDM and the role of fillers were revealed. The UV aging of the coating significantly reduced the infrared emissivity (Reduced from 0.5 to 0.2). Al powder effectively reduced the UV degradation rate of the coating by reflecting UV light. The properties of the double‐formulated coating perform best after UV aging.

Climate, litter quality and radiation duration jointly regulate the net effect of UV radiation on litter decomposition

Photodegradation via ultraviolet (UV) radiation is an important factor driving plant litter decomposition. Despite increasing attention to the role of UV photodegradation in litter decomposition, the specific impact of UV radiation on the plant litter decomposition stage within biogeochemical cycles remains unclear at regional and global scales. To clarify the variation rules of magnitude of UV effect on plant litter decomposition and their regulatory factors, we conducted a meta-analysis based on 54 published papers. Our results indicated that UV significantly promoted the mass loss of litter by facilitating decay of carbonaceous fractions and release of nitrogen and phosphorus. The promotion effect varied linearly or non-linearly with the time that litter exposed to UV, and with climatic factors. The UV effect on litter decomposition decreased first than increased on precipitation and temperature gradients, reaching its minimum in the area with a precipitation of 400–600 mm, and a temperature of 15–20 °C. This trend might be attributed to a potential equilibrium between the photofacilitation and photo-inhibition effects of UV under this condition. This variation in UV effect on precipitation gradient was in agreement with the fact that UV photodegradation effect was weakest in grassland ecosystems compared to that in forest and desert ecosystems. In addition, initial litter quality significantly influenced the magnitude of UV effect, but had no influence on the correlation between UV effect and climate gradient. Litter with lower initial nitrogen and lignin content shown a greater photodegradation effect, whereas those with higher hemicellulose and cellulose content had a greater photodegradation effect. Our study provides a comprehensive understanding of photodegradation effect on plant litter decomposition, indicates potentially substantial impacts of global enhancements of litter decomposition by UV, and highlights the necessity to quantify the contribution of photochemical minerallization pathway and microbial degradation pathway in litter decomposition.

Investigation on UV Degradation and Mechanism of 6:2 Fluorotelomer Sulfonamide Alkyl Betaine, Based on Model Compound Perfluorooctanoic Acid

The UV treatment of 6:2 FTAB involves the mitigation of this persistent chemical by the impact of ultraviolet radiation, which is known for its resistance to environmental breakdown. UV treatment of PFOA and/or 6:2 FTAB, and the role of responsible species and their mechanism have been presented. Our investigation focused on the degradation of perfluorooctanoic acid (PFOA) and 6:2 fluorotelomer sulfonamide alkyl betaine (6:2 FTAB, Capstone B), using UV photolysis under various pH conditions. Initially, we used PFOA as a reference, finding a 90% decomposition after 360 min at the original (unadjusted) pH 5.6, with a decomposition rate constant of (1.08 ± 0.30) × 10−4 sec−1 and a half-life of 107 ± 2 min. At pH 4 and 7, degradation averaged 85% and 80%, respectively, while at pH 10, it reduced to 57%. For 6:2 FTAB at its natural pH 6.5, almost complete decomposition occurred. The primary UV transformation product was identified as 6:2 fluorotelomer sulfonic acid (6:2 FTSA), occasionally accompanied by shorter-chain perfluoroalkyl acids (PFAAs) including PFHpA, PFHxA, and PFPeA. Interestingly, the overall decomposition percentages were unaffected by pH for 6:2 FTAB, though pH influenced rate constants and half-lives. In PFOA degradation, direct photolysis and reaction with hydrated electrons were presumed mechanisms, excluding the involvement of hydroxyl radicals. The role of superoxide radicals remains uncertain. For 6:2 FTAB, both direct and indirect photolysis were observed, with potential involvement of hydroxyl, superoxide radicals, and/or other reactive oxygen species (ROS). Clarification is needed regarding the role of eaq− in the degradation of 6:2 FTAB.

Understsanding the Effects of UV Radiation on Climate Change: A Comprehensive Review

‌This review paper explores the intricate relationship between ultraviolet (UV) radiation and climate change, delving into its multifaceted effects on atmospheric processes, global temperature dynamics, biological entities, and the intricate feedback mechanisms that shape the Earth's climate. Beginning with an examination of UV radiation's interaction with the atmosphere, we uncover its role in ozone layer dynamics and its potential to influence atmospheric circulation patterns.The discussion extends to the impact of UV radiation on global temperature patterns, emphasizing its contribution to the Earth's energy balance and its interaction with greenhouse gases. Moving beyond climatic elements, we explore the biological impacts of UV radiation, encompassing its effects on human health, plant productivity, and aquatic ecosystems. We unveil the intricate feedback loops, revealing how changes induced by UV radiation can cascade through the atmosphere, ecosystems, and human societies.The technological and policy implications are scrutinized, highlighting innovations in monitoring and mitigation strategies alongside international policies crafted to address UV radiation's impact on climate change. Looking toward the future, the paper offers insights into potential advancements, challenges, and opportunities, emphasizing the need for ongoing research, global collaboration, and sustainable practices to navigate the evolving dynamics of UV radiation and climate change. In conclusion, this review consolidates a comprehensive understanding of UV radiation's pivotal role in shaping our climate, offering a foundation for informed decision-making and sustainable stewardship of our planet

Biomarkers of UVB radiation-related senescent fibroblasts

Excessive exposure to ultraviolet (UV) light is known to induce photoaging in the skin, necessitating the development of effective anti-photoaging strategies to mitigate the adverse effects of UV radiation. Understanding the biofunctional characteristics of diverse skin cell types and unraveling the molecular modifications implicated in the aging process are pivotal in comprehending the intricacies of photoaging in human skin. Such insights are essential for paving the way for innovative interventions to counteract the deleterious impact of UV radiation on the skin. The single-cell RNA sequencing data of UVB-irradiated and normal control mouse skin in GSE173385 were downloaded from the Gene Expression Omniniub (GEO) database. First, cell types were identified using Seurat for normalization, dimensionality reduction and clustering. Next, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis were executed on these cell subpopulations. Using FindAllMarkers in the Seurat package to identify differential gene expression and Monocle2 cell trajectory analysis, we screened out hub genes related to the development trajectory of senescent fibroblasts during photoaging, and then combined it with 307 aging-related genes collected in the HAGR library, we finally identified two biomarkers. The efficiency of biomarkers in diagnosing UV radiation photoaging was also evaluated in the dataset. Concurrently, the immune infiltration of identified biomarkers under UV radiation has also been further explored. Moreover, we employed the Enrichr platform to conduct a comprehensive screening of drug molecules associated with the identified biomarkers. Our comprehensive analysis, employing Seurat for normalization, dimensionality reduction, and clustering, successfully identified ten distinct cell types within the samples. Then GO functional enrichment analysis showed that senescent fibroblasts are mainly involved in the regulation of immune effector processes such as cytokine-mediated signaling pathways, regulation of epithelial cell proliferation and intercellular adhesion. Afterwards, KEGG analysis determined the main biological pathways are: IL-17 signaling pathway, Cytokine–cytokine receptor interaction, Metabolism of xenobiotics by cytochrome P450. After differential gene expression and Monocle2 cell trajectory analysis, we matched the obtained hub genes with the aging-related genes collected in the HAGR library, and finally screened out two relevant biomarkers: Apoe and Gdf15 which are related to the development trajectory of senescent fibroblasts during photoaging. Meanwhile, the immune infiltration further implied that the expression of these two biomarkers was significantly correlated with immune cells. In addition, the Enrichr platform was used to screen the drug molecules related to these biomarkers. This strategic approach aimed to pinpoint effective molecular targets for the prevention and treatment of photoaging. Our investigation has effectively characterized biomarkers associated with fibroblast senescence during photoaging at the single-cell level, We have validated their correlation with cellular immune inflammation and identified potential drug targets through the utilization of the Enrichr platform. This foundational research establishes a robust basis for the development of therapeutic interventions targeting skin diseases resulting from photoaging.

Impacts of UV radiation on Bacillus biocontrol agents and their resistance mechanisms.

Bacillus biocontrol agent(s) BCA(s) such as Bacillus cereus, Bacillus thuringiensis and Bacillus subtilis have been widely applied to control insects' pests of plants and pathogenic microbes, improve plant growth, and facilitate their resistance to environmental stresses. In the last decade, researchers have shown that, the application of Bacillus biocontrol agent(s) BCA(s) optimized agricultural production yield, and reduced disease risks in some crops. However, these bacteria encountered various abiotic stresses, among which ultraviolet (UV) radiation severely decrease their efficiency. Researchers have identified several strategies by which Bacillus biocontrol agents resist the negative effects of UV radiation, including transcriptional response, UV mutagenesis, biochemical and artificial means (addition of protective agents). These strategies are governed by distinct pathways, triggered by UV radiation. Herein, the impact of UV radiation on Bacillus biocontrol agent(s) BCA(s) and their mechanisms of resistance were discussed.

Development of innovative equipment for milk microflora inactivation

The article is dedicated to the development of innovative equipment for the inactivation of milk microflora. It provides an analysis of existing methods to suppress the growth and destruction of microorganisms in milk, aiming to enhance product quality indicators. The advantages and disadvantages of current pasteurization equipment are highlighted. An overview of alternative methods for milk inactivation is presented, focusing on the impact of ultraviolet radiation on bacteria and lower organisms. It is concluded that a major advantage of ultraviolet (UV) milk treatment, in addition to its bactericidal effect, is its minimal impact on proteins under efficient operating conditions. Considering the limited penetration of UV rays into milk, a device is proposed—a milk disinfection separator that separates microorganisms from the main product by placing them in the form of a thin laminar film accessible for effective irradiation. Special attention is given to justifying the parameters of the UV irradiation section. The methodology for hydraulic calculation of device movement is presented, along with a method for determining the bactericidal effectiveness of UV irradiation on microorganisms and the necessary lethal dose for this purpose. By specifying the system's productivity, knowing the bactericidal dose required to deactivate bacteria, and considering the irradiation intensity of the UV source, the dimensions of the irradiation section and the required electrical power of the equipment are determined. The article proposes modern LED arrays with the necessary UV wavelength range, along with diagrams for their connection and equipment control.

Study on asphalt damage characteristics in cold area with large temperature gradient

The primary cause of the asphalt pavement disease in this region is the large temperature differential and high ultraviolet (UV) radiation that characterize this frigid environment. This study assessed the ductility, penetration, softening point, and rheological properties of several asphalts under various freeze-thaw cycles and UV aging conditions. Additionally, the damage characteristics of asphalt in cold and large temperature gradient areas were examined. The findings indicate that the freeze-thaw cycle significantly affects the asphalt’s low-temperature crack resistance but has no discernible effect on the material’s traditional performance or high-temperature rutting resistance. Asphalt’s resistance to low temperature cracking is ranked according to the impacts of UV radiation and the freeze-thaw cycle: 80/100 pen grade asphalt, 100/120 pen grade asphalt, SBS modified asphalt, and SBR modified asphalt. The impact of UV radiation and the freeze-thaw cycle on the high temperature performance of asphalt is categorized into four categories: SBR modified asphalt, SBS modified asphalt, 80/100 pen grade asphalt, and 100/120 pen grade asphalt.

Synergistic effects of salt and ultraviolet radiation on the rice-field cyanobacterium Nostochopsis lobatus HKAR-21.

Environmental variation has a significant impact on how organisms, including cyanobacteria, respond physiologically and biochemically. Salinity and ultraviolet radiation (UVR)-induced variations in the photopigments of the rice-field cyanobacterium Nostochopsis lobatus HKAR-21 and its photosynthetic performance was studied. We observed that excessive energy dissipation after UVR is mostly caused by Non-Photochemical Quenching (NPQ), whereas photochemical quenching is important for preventing photoinhibition. These findings suggest that ROS production may play an important role in the UVR-induced injury. To reduce ROS-induced oxidative stress, Nostochopsis lobatus HKAR-21 induces the effective antioxidant systems, which includes different antioxidant compounds like carotenoids and enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). The study indicates that Nostochopsis lobatus HKAR-21 exposed to photosynthetically active radiation + UV-A + UV-B (PAB) and PAB + NaCl (PABN) had significantly reduced photosynthetic efficiency. Furthermore, maximum ROS was detected in PAB exposed cyanobacterial cells. The induction of lipid peroxidation (LPO) has been investigated to evaluate the impactof UVR on the cyanobacterial membrane in addition to enzymatic defensive systems. The maximal LPO level was found in PABN treated cells. Based on the findings of this research, it was concluded that salinity and UVR had collegial effects on the major macromolecular components of the rice-field cyanobacterium Nostochopsis lobatus HKAR-21.

Novel Method for Assessing the Protection Lifetime of Building Coatings against Fungi

The aim of this study was to develop a novel method for evaluating the service life of building coatings. In Stage 1, we assessed existing methods for determining the degree of fungal overgrowth on building materials (visual assessment, culture method, luminometric ATP (adenosine-5’-triphosphate) measurement, and spectrophotometric assessment of colour changes). Laboratory tests were carried out for 19 types of facade coating (mineral and silicone with/without primer, silicone paint, biocides) and 7 fungal strains (moulds Alternaria alternata, Aspergillus niger, Aureobasidium melanogenum, Cladosporium cladosporioides, Fusarium sp., Penicillium citrinum, and the yeast Rhodotorula mucilaginosa). The number of fungi on the facade coatings after 28 days of incubation was 1.7 × 105–4.6 × 105 CFUs (colony-forming units)/sample. The ATP content was 12 RLUs–30333 RLUs (relative light units). Colour change was ΔE > 5 depending on the coating type and fungal strain. A high or very high correlation was found between the ATP concentration (RLUs), colour change (ΔE), and the results of the culture method (CFUs/sample). In Stage 2, a new methodology for evaluating the protection lifetime of building coatings against fungi was developed, taking into account environmental conditions (impact of ultraviolet radiation, precipitation, presence of organic matter on the surface, quantitative and qualitative composition of bioaerosol). The developed method consists of one research cycle conducted in the laboratory, corresponding to one year under natural conditions. Preliminary verification showed the model to be compatible with long-term observations (3 years) of fungal growth on the facade coatings under real environmental conditions. The novel method could be used to design biodeterioration control and protection strategies for both new and cultural heritage buildings.

The Effect of Ultraviolet Radiation on Mechanical Properties of Fused Deposition Modeling 3D Printed Materials

This study investigates the influence of ultraviolet (UV) radiation on the mechanical properties of Fused Deposition Modeling (FDM) 3D printed materials, specifically polycarbonate (PC) and polylactic acid (PLA) specimens. The research involves conducting experiments on five test specimens of each material exposed to UV radiation and comparing their mechanical properties to those of five control specimens that remain unexposed. The results reveal a significant mean difference between the mechanical properties of the control and UV-exposed materials. UV radiation caused a decrease in tensile strength for the PC material, while the PLA material exhibited an increase in tensile strength. The impact of UV radiation on PLA was more substantial compared to PC. Flexural strength testing showed an enhancement in strength for the UV-treated materials, with UV treatment having a greater influence on the flexural strength of PLA compared to PC. The mechanical properties of PLA were more significantly impacted by UV radiation than those of PC. The study findings suggest that PC and PLA materials exhibit different responses to UV exposure, which may have implications for their practical applications. Further research is needed to fully understand the underlying mechanisms governing these divergent responses and to optimize the performance of each material under UV radiation.

Impact of ultraviolet radiation on cardiovascular and metabolic disorders: The role of nitric oxide and vitamin D.

Ultraviolet (UV) radiation has both harmful and beneficial effects on human skin and health. It causes skin damage, aging, and cancer; however, it is also a primary source of vitamin D. Additionally, UV radiation can impact energy metabolism and has protective effects on several cardiovascular and metabolic disorders in mice and humans. However, the mechanisms of UV protection against these diseases have not been clearly identified. This review summarizes the systemic effects of UV radiation on hypertension and several metabolic diseases such as obesity, diabetes, and nonalcoholic fatty liver disease (NAFLD) in mice, and we also consider the mechanisms of action of the related regulators nitric oxide (NO) and vitamin D. UV exposure can lower blood pressure and prevent the development of cardiovascular diseases and metabolic disorders, such as metabolic syndrome, obesity, and type 2 diabetes, primarily through mechanisms that depend on UV-induced NO. UV radiation may also effectively delay the onset of type 1 diabetes through mechanisms that rely on UV-induced vitamin D. UV-induced NO and vitamin D play roles in preventing and slowing the progression of NAFLD. UV exposure is a promising nonpharmacological intervention for cardiovascular and metabolic disorders. NO and vitamin D may play a crucial role in mediating these effects. However, further investigations are required to elucidate the exact mechanisms and determine the optimal dosage and exposure duration of UV radiation.

Electronic and Photochemical Passivation by a Classic Sunscreen Material Leading to Reduced Voc Losses and Enhanced Stability in Organic Solar Cells.

Organic solar cells (OSCs) have been a popular topic of research for a long time. As a well-known electron transport layer (ETL) material for inverted device architecture, sol-gel-derived zinc oxide (ZnO) displays certain defective surfaces that cause excessive charge recombination and lower device performance. While ultraviolet (UV)-light soaking is sometimes necessary for the ZnO layer to function properly, the latter can also cause the photodegradation of conjugated organic semiconductors. The photostability of OSCs has always been a hot research topic, as the radiation of UV light may cause changes in the material's properties, and that, in turn, may cause rapid attenuation of the devices. Herein, ZnO is modified by inserting the commonly used sunscreen ingredient benzophenone-3 (BP-3) between the photoactive layer, consisting of a PM6:Y6 blend, and ZnO to reduce the impact of UV radiation on the photosensitive layer. The addition of BP-3 successfully enhances the photovoltaic parameters, and a remarkable open-circuit voltage (Voc) value of 0.887 V is obtained for PM6:Y6-based inverted solar cells, corresponding to a Voc loss as small as 0.547 V. Finally, the application of this strategy increases the device's power conversion efficiency from 12.44 to 13.71% and provides improved UV stability.

An investigation on effect of ultraviolet (UV) rays on mechanical properties of epoxy laminates

The use of epoxy resins has significantly grown in many industrial applications due to their exceptional mechanical and chemical properties. However, their susceptibility to Ultraviolet (UV) light damage and exposure to outdoor weather conditions remains a major limitation. In order to address this drawback, UV absorbers have been frequently employed to reduce the rate of UV degradation. This study investigates the impact of UV radiation on the physical, chemical, and mechanical characteristics of cured epoxy laminates. The results indicate that UV radiation causes a significant reduction in tensile strength by 22.6% after 180 h of exposure. Furthermore, UV–Visible and Fourier-transform infrared spectroscopy (FTIR) spectroscopy measurements demonstrate significant chemical and optical modifications in the epoxy matrix, leading to the deterioration of its properties. These findings provide valuable insights for designing new epoxy formulations that can withstand harsh environmental conditions and improve the durability and performance of epoxy-based products.

Impact of ultraviolet radiation on the skin and the role of photoprotection – the review of the literature

Introduction and objective: 
 The sun emits ultraviolet radiation in the UV-A, UV-B and UV-C ranges. Photoprotection is used to prevent the impact of this radiation on the skin. It effectively counteracts photoaging, photodermatoses and photocarcinogenesis.
 The aim of the study is to discuss the impact of UV radiation on the skin and the role of sun protection, also in special groups of patients - children and non-immunocompetent people. The article also presents a summary of data on the effect of sunscreens on vitamin D synthesis.
 Materials and methods: 
 The literature was reviewed in the Pubmed, Google Scholar database and in the recommendations of the Polish Dermatological Society with the use of keywords.
 State of knowledge: 
 Erythema is the most visible effect of sunburn, but exposure to UV radiation is primarily photocarcinogenesis or photoimmunosuppression. The SPF factor is the main determinant of the effectiveness of sunscreens, but effective protection against both UVB and UVA radiation is essential. Daily use of sunscreen reduces skin damage associated with exposure to light and does not negatively affect vitamin D synthesis.
 Conclusions:
 The basis of skin protection is using sunscreens, avoiding excessive exposure to solar radiation and using protective clothing, hats and sunglasses. Thanks to these activities, we can significantly reduce the number of cases of certain skin cancers. It is also important to remember that sun protection applies to everyone, especially children and non-immunocompetent people.

Impact of ultraviolet radiation nearly overrides the effects of elevated pCO2 on a prominent nitrogen‐fixing cyanobacterium

AbstractAlthough the marine N2‐fixers Trichodesmium spp. are affected by increasing pCO2 and by ultraviolet radiation (UVR) in their habitats, little is known on their potential responses to future ocean acidification in the presence of UVR. We grew Trichodesmium at two pCO2 levels (410 and 1000 μatm) under natural sunlight, documented the filament length, growth, and chlorophyll content after its acclimation to the pCO2 treatments, and measured its carbon and N2 fixation rates under different solar radiation treatments with or without UVR. We showed that the elevated pCO2 did not significantly alter the diazotroph's growth, filament length, or pigment content, and its photosynthetic rate was only affected by solar radiation treatments rather than the pCO2 levels. The presence of UV‐A and UV‐B inhibited photosynthesis by 10–22% and 17–21%, respectively. Inhibition of N2 fixation by UV‐B was proportional to its intensity, whereas UV‐A stimulated N2 fixation at low, but inhibited it at high, intensities. Elevated pCO2 only stimulated N2 fixation under moderate levels of solar radiation. The simulated depth profile of N2 fixation in the water column showed that UV‐induced inhibition dominated the combined effects of elevated pCO2 and UVR at 0–30 m depth and the combination of these factors enhanced N2 fixation at 30–60 m depth, but this effect diminished in deeper water. Our results suggest that Trichodesmium could be influenced more by UVR than by pCO2 and their combined action result in negative effects on N2 fixation under high solar radiation, but positive effects under low to moderate solar radiation.