Doses Of Ultraviolet Radiation Research Articles

Improving Photoprotection and Implications for 25(OH)D Formation.

This review examined the implications of using sunscreen photoprotection on 25(OH)D formation and determined the best photoprotective method to reduce the risk of skin cancer caused by ultraviolet radiation (UVR). Based on previous studies on 25(OH)D formation after use of different amounts of sunscreen and different doses of UVR for approximately one week to different body areas it is possible to estimate the amount of 25(OH)D formed after a week's holiday in Southern and Northern Europe. The best method of photoprotection by sunscreen is two consecutive applications before sun exposure, ensuring the use of sufficient amounts of sunscreen and minimizing the unprotected skin areas. The double application method simultaneously ensures a high photoprotection against erythema from sun exposure. Despite the use of sunscreen, the calculated serum 25(OH)D levels clearly increase to similar levels as those measured after sun vacations.

Lifetime UVR Dose and Skin Cancer Risk, Determined by Their Common Relation to Solar Lentigines.

Ultraviolet radiation (UVR) causes solar lentigines (SL) and skin cancer (SC) in humans. The association between measured lifetime UVR dose and SC has not been investigated. This study investigated this relation through their common relationship to SL. First we investigated the association between lifetime UVR dose and SL for 16,897 days in 38 healthy participants, and secondly, the relation between SL and SC was investigated in 2,898 participants, including 149 with SC. By combining both studies, SC risk related to lifetime UVR dose and skin phototype was estimated. A positive association was found between SL and lifetime UVR dose (p=0.060). Skin phototype (p=0.001) and SL (p<0.001) were associated with SC. Combined SC risk increased 1.23 by doubling the average lifetime UVR dose and was 34.9 times higher for those with very fair skin compared to dark Mediterranean skin. The estimate of SC risk shows that skin phototype is of greater relative importance than lifetime UVR dose.

Parametric human modelling to determine body surface area covered by sun-protective clothing

Solar ultraviolet radiation (UVR) is the main environmental risk-factor for cancer of the skin. Sun-protective clothing provides a physical barrier that reduces the UVR dose reaching the skin and European and Australian standards for sun-protective clothing set minimum clothing coverage requirements. Body Surface Area Coverage by clothing (BSAC) is calculated by means of indirect or direct methods, which are laborious and do not support computer-based apparel design. To support the sun-safe specification and design of garments, parametric digital human models and protective clothing mesh covering the minimum Body Surface Area specified in AS/NZS 4399:2017, were created making use of MakeHuman v1.1.1 and Blender software. The Whole Body Surface Area (WBSA) and the BSAC were calculated employing code developed in Blender. Thus, different groups of subjects were analysed to explore BSAC. The method assists in the evaluation of exposed body areas in a wider spectrum of different occupations. Practitioner summary: Sun-protective clothing provides a physical barrier that reduces the UVR dose reaching the skin’s surface. Body Surface Area Coverage (BSAC) by clothing is an important determinant of the sun protective capabilities of a garment. In this study, BSAC is calculated using parametric digital human modelling. Abbreviation: UVR: (Solar) ultraviolet radiation; DHM: digital human modeling; BSA: body surface area; BSAC: body surface area coverage (by clothing); BSANC: body surface area not covered (by clothing); WBSA: whole body surface area; BCC: basal cell carcinoma; SCC: squamous cell carcinoma; UPF: ultraviolet protection factor; GPF: garment protection factor

Dose‐dependent density change of lens epithelial cells after in vivo UVR exposure

AbstractIntroductionOur research group focuses on the mechanism of ultraviolet radiation (UVR) induced lens damage. Posterior capsule opacification (PCO) is the most common complication for cataract surgery. PCO results from the growth and abnormal proliferation of lens epithelial cells (LECs) on the posterior capsule. Lens epithelium is the first target for toxic factors such as ultraviolet radiation. UVR‐300 nm (UVR‐B) is especially an important risk factor for cataract development. Our previous findings show that exposure to UVR‐B can damage the lens epithelium, affect the expression of proteins, induce apoptosis and lead to cataract formation. Therefore, it is possible to prevent PCO by sufficient dose exposure of ultraviolet radiation to residual lens epithelial cells after cataract surgery.PurposeTo determine the effect of different doses of UVR on the distribution of lens epithelial cells (LECs).MethodsAltogether, 40 Sprague Dawley rats were unilaterally exposed in vivo to 1, 3, 6 and 8 kJ/m2 UVR‐300 nm for 15 min. One week after UVR exposure, exposed and contralateral non‐exposed lenses were removed. One midsagittal section from each lens was stained with DAPI for fluorescence microscopy in order to determine the spatial distribution of LECs.ResultsThe LECs density difference between exposed and contralateral non‐exposed eyes at exposure dose of 1, 3, 6 and 8 kJ/m2 was estimated as a CI (95%), −0.1 ± 2.1, 0.1 ± 3.0, −4.1 ± 1.4 and −2.9 ± 2.7 Cell μm−1 10−2, respectively. Data was fit to a linear model considering the initial density difference at 0. The inclination coefficient was estimated as CI (95%), −0.4 ± 0.1 Cell μm kJ−1 1010.ConclusionUVR‐300 nm induces significant LECs density decrease at exposure dose ≥6 kJ/m2. With fitting to a linear model the evolution of dose‐cell density dependence can be determined.

Dose and time effects of solar‐simulated ultraviolet radiation on the in vivo human skin transcriptome

SummaryBackgroundTerrestrial ultraviolet (UV) radiation causes erythema, oxidative stress, DNA mutations and skin cancer. Skin can adapt to these adverse effects by DNA repair, apoptosis, keratinization and tanning.ObjectivesTo investigate the transcriptional response to fluorescent solar‐simulated radiation (FSSR) in sun‐sensitive human skin in vivo.MethodsSeven healthy male volunteers were exposed to 0, 3 and 6 standard erythemal doses (SED). Skin biopsies were taken at 6 h and 24 h after exposure. Gene and microRNA expression were quantified with next generation sequencing. A set of candidate genes was validated by quantitative polymerase chain reaction (qPCR); and wavelength dependence was examined in other volunteers through microarrays.ResultsThe number of differentially expressed genes increased with FSSR dose and decreased between 6 and 24 h. Six hours after 6 SED, 4071 genes were differentially expressed, but only 16 genes were affected at 24 h after 3 SED. Genes for apoptosis and keratinization were prominent at 6 h, whereas inflammation and immunoregulation genes were predominant at 24 h. Validation by qPCR confirmed the altered expression of nine genes detected under all conditions; genes related to DNA repair and apoptosis; immunity and inflammation; pigmentation; and vitamin D synthesis. In general, candidate genes also responded to UVA1 (340–400 nm) and/or UVB (300 nm), but with variations in wavelength dependence and peak expression time. Only four microRNAs were differentially expressed by FSSR.ConclusionsThe UV radiation doses of this acute study are readily achieved daily during holidays in the sun, suggesting that the skin transcriptional profile of ‘typical’ holiday makers is markedly deregulated. What's already known about this topic? The skin's transcriptional profile underpins its adverse (i.e. inflammation) and adaptive molecular, cellular and clinical responses (i.e. tanning, hyperkeratosis) to solar ultraviolet radiation.Few studies have assessed microRNA and gene expression in vivo in humans, and there is a lack of information on dose, time and waveband effects. What does this study add? Acute doses of fluorescent solar‐simulated radiation (FSSR), of similar magnitude to those received daily in holiday situations, markedly altered the skin's transcriptional profiles.The number of differentially expressed genes was FSSR‐dose‐dependent, reached a peak at 6 h and returned to baseline at 24 h.The initial transcriptional response involved apoptosis and keratinization, followed by inflammation and immune modulation. In these conditions, microRNA expression was less affected than gene expression.

Statistical Modeling of UV-Induced PV Module Power Degradation Based on Acceleration Tests

The ultraviolet (UV) induced photovoltaic (PV) module power degradation is researched though the statistics of qualification test results based on IEC 61215:2005. The power degradation rate after UV preconditioning tests is found satisfying the Weibull distribution and the related parameters are calculated under different UV radiation doses. Then, the evolution regularity of degradation rate distribution is modeled by fitting the parameters with acceleration models and the probability density distribution of UV-induced degradation rate is predicted with consideration of the propagated uncertainty. The result tells that 95.0% $ \pm $ 4.045% polysilicon PV modules degrading no more than 8% after 3000 kWh/m2 UV exposure and the distribution of degradation rate under high UV dose tend to concentrate round the maximum probability point. As the temperature in our calculation is fixed at 60 °C which is higher than the actual outdoor operation temperature, the UV-induced degradation rate is expected to be lower after 25-year exposure.

COMPARATIVE STABILITY OF POLIOVIRUS, HEPATITIS A VIRUS AND THEIR RNA TO THE IMPACT OF ULTRAVIOLET RADIATION

Introduction. The results of experimental studies on the comparative assessment of the effects of various doses of UV radiation on the survival of poliovirus type I LSc2ab, phage MS-2, hepatitis A viruses and their RNA in tap water are presented. Material and methods. Poliomyelitis viruses of type I strain LSc2ab (PV), viruses of hepatitis A, strain HAS-15 (HAV), phages MS-2, free RNA isolated from hepatitis viruses and poliomyelitis were introduced into model reservoirs with dechlorinated Moscow tap water. Water samples were taken from each tank and subjected to ultraviolet irradiation (UVR) with a wavelength of 254 nm with doses of 25, 40, 60, 80 and 100 mJ/cm2. PV titration was performed on a BGM monkey kidney cell transplant line; MS-2 phages were determined by the agar layer method using the E. coli K12F + Str. detector; determination of PV RNA and HAV was carried out on the Rotor GeneTM 6000 amplifier in RT-PCR reaction in real-time using appropriate test systems. Extraction and isolation of RNA from samples of PV and HAV were also performed using reagent kits of domestic and foreign production. Results. Ultraviolet irradiation in doses from 25 to 100 mJ/cm2 was shown to have a pronounced inhibitory effect on phages MS-2 and PV, determined by traditional methods in accordance with the methodological guidelines MUK 4.2.1018-01 and MUK 4.2.2029-05. At UVR doses of 80 and 100 mJ/cm2, complete inactivation of MS-2 and PV phages in water was noted. At the same time, these same doses of UVR had a less inhibitory effect on PVA, HAV RNA, as well as on isolated free PVA RNA/X and HAV, which were more stable and continued to be determined by RT-PCR in water at all doses of UVR, including 80 and 100 mJ/cm2. Conclusion. If only RNA viruses are detected in the treated drinking water and there are no other direct or indirect indices of viral contamination, it is impossible to unambiguously judge the extent of the potential epidemic hazard of the water body. This requires the development of reliable additional tests confirming the infectivity of viruses, determined only by RNA or DNA markers.

Characterising nitric oxide-mediated metabolic benefits of low-dose ultraviolet radiation in the mouse: a focus on brown adipose tissue.

Exposure to sunlight has the potential to suppress metabolic dysfunction and obesity. We previously demonstrated that regular exposure to low-doses of ultraviolet radiation (UVR) reduced weight gain and signs of diabetes in male mice fed a high-fat diet, in part via release of nitric oxide from skin. Here, we explore further mechanistic pathways through which low-dose UVR exerts these beneficial effects. We fed mice with a luciferase-tagged Ucp1 gene (which encodes uncoupling protein-1 [UCP-1]), referred to here as the Ucp1 luciferase transgenic mouse ('Thermomouse') a high-fat diet and examined the effects of repeated exposure to low-dose UVR on weight gain and development of metabolic dysfunction as well as UCP-1-dependent thermogenesis in interscapular brown adipose tissue (iBAT). Repeated exposure to low-dose UVR suppressed the development of glucose intolerance and hepatic lipid accumulation via dermal release of nitric oxide while also reducing circulating IL-6 (compared with mice fed a high-fat diet only). Dietary nitrate supplementation did not mimic the effects of low-dose UVR. A single low dose of UVR increased UCP-1 expression (by more than twofold) in iBAT of mice fed a low-fat diet, 24 h after exposure. However, in mice fed a high-fat diet, there was no effect of UVR on UCP-1 expression in iBAT (compared with mock-treated mice) when measured at regular intervals over 12weeks. More extensive circadian studies did not identify any substantial shifts in UCP-1 expression in mice exposed to low-dose UVR, although skin temperature at the interscapular site was reduced in UVR-exposed mice. The appearance of cells with a white adipocyte phenotype ('whitening') in iBAT induced by consuming the high-fat diet was suppressed by exposure to low-dose UVR in a nitric oxide-dependent fashion. Significant shifts in the expression of important core gene regulators of BAT function (Dio2, increased more than twofold), fatty acid transport (increased Fatp2 [also known as Slc27a2]), lipolysis (decreased Atgl [also known as Pnpla2]), lipogenesis (decreased Fasn) and inflammation (decreased Tnf), and proportions of macrophages (increased twofold) were observed in iBAT of mice exposed to low-dose UVR. These effects were independent of nitric oxide released from skin. Our results suggest that non-burning (low-dose) UVR suppresses the BAT 'whitening', steatotic and pro-diabetic effects of consuming a high-fat diet through skin release of nitric oxide, with some metabolic and immune pathways in iBAT regulated by UVR independently of nitric oxide.

Oxidative stress in corneal injuries of different origin: Utilization of 3D human corneal epithelial tissue model

The purpose of the current work was to utilize a three dimensional (3D) corneal epithelial tissue model to study dry eye disease and oxidative stress-related corneal epithelial injuries for the advancement of ocular therapeutics. Air-liquid interface cultures of normal human corneal epithelial cells were used to produce 3D corneal epithelial tissues appropriate for physiologically relevant exposure to environmental factors. Oxidative stress was generated by exposing the tissues to non-toxic doses of ultraviolet radiation (UV), hydrogen peroxide, vesicating agent nitrogen mustard, or desiccating conditions that stimulated morphological, cellular, and molecular changes relevant to dry eye disease. Corneal specific responses, including barrier function, tissue viability, reactive oxygen species (ROS) accumulation, lipid peroxidation, cytokine release, histology, and gene expression were evaluated. 3D corneal epithelial tissue model structurally and functionally reproduced key features of molecular responses of various types of oxidative stress-induced ocular damage. The most pronounced effects for different treatments were: UV irradiation - intracellular ROS accumulation; hydrogen peroxide exposure - barrier impairment and IL-8 release; nitrogen mustard exposure - lipid peroxidation and IL-8 release; desiccating conditions - tissue thinning, a decline in mucin expression, increased lipid peroxidation and IL-8 release. Utilizing a PCR gene array, we compared the effects of corneal epithelial damage on the expression of 84 oxidative stress-responsive genes and found specific molecular responses for each type of damage. The topical application of lubricant eye drops improved tissue morphology while decreasing lipid peroxidation and IL-8 release from tissues incubated at desiccating conditions. This model is anticipated to be a valuable tool to study molecular mechanisms of corneal epithelial damage and aid in the development of therapies against dry eye disease, oxidative stress- and vesicant-induced ocular injuries.

Facial photoprotection in xeroderma pigmentosum (XP) patients: Validation of a new self-reported questionnaire of adherence.

Adherence to photoprotection is the only way to prevent skin cancers and eye disease in xeroderma pigmentosum (XP). No validated self-report questionnaire exists for assessing adherence to photoprotection practices in individuals with XP. We sought to validate a self-reported measure of adherence to face photoprotection in this population. Sixty six XP patients recruited from the patient list of the XP specialist service in London, UK, completed a questionnaire of adherence to specific photoprotection behaviours. We measured objective ultraviolet radiation (UVR) exposure to the face continuously for 21days with a wristworn UVR electronic dosimeter combined with a daily photoprotection diary. Reliability and convergent validity of the questionnaire were tested in relation to overall UVR exposure, UVR dose to the face, daily photoprotection activities, other self-reported photoprotection practices and clinical ratings of patient's protection. Internal consistency of the questionnaire was satisfactory. Questionnaire total scores were concordant with objective UVR exposure and UVR dose to the face. However, not all participants who reported good/excellent face photoprotection on the questionnaire recorded high levels of photoprotection in the daily diary. Correlations between the questionnaire and other practices and the clinical rating ranged from small to large in size. There was no correlation between the level of face photoprotection and self-reported avoidance of going outside. Our questionnaire was reliable and had good convergent validity with other indicators of photoprotection. This questionnaire could assist clinicians to detect low levels of adherence, and the methodology used to develop validated questionnaires for other photosensitive conditions.

Study of skin rigidity variations due to UV radiation using digital holographic interferometry

The skin elasticity is a relevant biomechanical property that can be related to different physiological processes and diseases: hence, it is important to understand and characterize the mechanisms that affect the skin pathologies. In this work, an analysis of the rigidity variations of porcine skin caused by exposure to ultraviolet radiation is presented. For this purpose digital holographic interferometry (dhi) is used as a non-invasive optical technique to study these skin affectations. A new mathematical scheme for the skin rigidity variations was developed and the experimental data was used to study and determine the rigidity coefficients for the samples before and after ultraviolet exposure of the skin. The results after high doses of ultraviolet radiation at 8 mW/cm2 UVA, 8 mW/cm2 UVB and 10 mW/cm2 UVC for periods of 3 min showed that these rigidity coefficients increased above 100% (more than twice) their value after the ultraviolet exposure. The latter suggests a considerable reduction of the porcine skin elasticity when exposed to high doses of ultraviolet radiation, a feature that has been proved to lead to skin melanoma.

Residual Flexural Performance of Epoxy Polymer Concrete under Hygrothermal Conditions and Ultraviolet Aging

Epoxy polymer concrete (EPC) has found increasing applications in infrastructure as a rising candidate among civil engineering materials. In most of its service environments, EPC is inevitably exposed to severe weather conditions, e.g., violent changes in temperature, rain, and ultraviolet (UV) radiation. In this paper, we designed an accelerated aging test for EPC, which includes periodic variation of temperature and water spray, as well as intensive UV-light irradiation, imitating the outdoor environment in South China. The experimental results show that the flexural performance of EPC is found deteriorate with the aging time. An aging process equivalent to four years (UV radiation dose) results in up to 8.4% reduction of flexural strength. To explore the mechanisms of observed performance degradation, the EPC specimen in the four-point-bending test is considered as a layered beam. The analysis indicates that the loss of flexural load-carrying capacity of an aged EPC beam is dominated by the reduction of mechanical properties of the surface layer. The mechanical properties of the surface layer are closely associated with the aging of epoxy mortar, which can be approximated as a reciprocal function of the aging time. By introducing damage to the surface layer into the layered beam, the proposed model demonstrates a good ability to predict the residual flexural strength of EPC during the aging process

Sun Exposure of Body Districts: Development and Validation of an Algorithm to Predict the Erythemal Ultra Violet Dose.

Solar Ultra-Violet (UV) radiation has positive and negative effects on human body tissues. Small doses of solar UV radiation are needed by the human skin for the activation of the vitamin D production. Overexposure to solar UV radiation can produce acute and long-term negative effects, such as sunburns and, in the worst cases, cataracts and skin cancers. For this reason, knowing the amount of UV doses received by people is essential to evaluate their risk to UV overexposure and to evaluate the adequate countermeasure to avoid the negative effects. The original contribution of the present study consists in having searched, collected, adapted and processed a series of technical information and analytical relations, developing an algorithm suitable for the calculation of the erythemal UV dose on sloped surfaces exposed to solar radiation, which at the moment is not present in the scientific literature. The results obtained by the algorithm have been compared to the results of a field measurements campaign, carried out in three different Italian sites. Results comparison indicated that measured and calculated values show a sufficient level of agreement, with a mean absolute error equal to 20%.

In Vivo Evaluation of the Anti-Inflammatory Activity of Electrospun Micro/Nanofibrous Patches Loaded with Pinus halepensis Bark Extract on Hairless Mice Skin.

Skin inflammation is the most common symptom in dermatological diseases. It is usually treated by topically applied products, such as creams, gels and lotions. Skin dressings offer a promising alternative as they are endowed with more controlled administration conditions. In this study, the anti-inflammatory activity of electrospun alginate micro/nanofibrous dressings loaded with the aqueous extract of Pinus halepensis bark (PHBE) was evaluated in vivo in mice. The upper back skin of SKH-1 female hairless mice was exposed to a single dose of ultraviolet radiation (3 MEDs) and the inflamed area was treated daily by the direct application of a nanofibrous patch. The condition of the skin was evaluated primarily on the basis of clinical observation, photo-documentation and histopathological assessment, while measurements of the erythema, hydration, transepidermal water loss (TEWL) and sebum production were also taken into account. The results showed that the topical application of alginate micro/nanofibrous dressings loaded with PHBE on UV-inflamed skin significantly attenuated inflammation damage, reducing the healing period. Increase of the loading dose of PHBE resulted in a proportional reduction of the extent, the density and the depth of skin inflammation. With the steadily increasing interest of the skin dressing industry towards nanofibrous matrices, electrospun nonwovens could serve as ideal candidates for the development of multifunctional anti-inflammatory care systems.

Pore size tuning of Nafion membranes by UV irradiation for enhanced proton conductivity for fuel cell applications

The influence of optimal ultraviolet irradiation of Nafion membranes in enhancing proton conductivity and performance of passive micro-direct methanol fuel cells with silicon micro-flow channels is investigated for the first time. Initially, Nafion membranes are irradiated with different doses of ultraviolet radiation ranging within 0–400 mJ cm−2 and their water uptake, swelling-ratios, porosity, and proton conductivities are measured using standard procedure. Results show that there is an enhancement in proton conductivity with an optimal dose of 198 mJ cm−2 ultraviolet radiation. This enhancement is due to optimum photo-crosslinking of –SO3H species resulting in maximum pore-size which facilitates enhanced proton-hopping from one –SO3H site to another in the hydrophilic channel. Nafion membranes with three different thicknesses (50 μm, 90 μm and 183 μm) are irradiated with ultraviolet radiation with 198 mJ cm−2 dose and passive micro-direct methanol fuel cells are assembled with irradiated Nafion proton exchange membranes. The polarization plots are obtained for the assembled devices. Results show an enhancement of power density of devices nearly by a factor of 1.2–1.5 with optimally irradiated membranes indicating that optimum dose of ultraviolet irradiation of Nafion membranes is an effective technique for power enhancement of proton exchange membrane fuel cells which use fuels like methanol, ethanol and hydrogen.

In vivo Change of Keratin-Bound Molecules in the Human Stratum Corneum following Exposure to Ultraviolet Radiation

Background/Objectives: Ultraviolet (UV) radiation damages the stratum corneum (SC) and disrupts the skin barrier. The damaged skin changes in the molecular composition of the SC, including its water content. However, it is difficult to examine the in vivo SC changes with existing methods, so those have not been well characterized. Therefore, we investigated in vivo changes of UV-induced SC damage using confocal Raman spectroscopy. Method: We irradiated the volar forearm of 10 subjects with 0.5, 1, and 1.5 minimal erythemal doses of UV radiation. Then, we examined erythema, the transepidermal water loss (TEWL), the water content, the natural moisturizing factor (NMF), and the lipids of the skin. Results: After UV irradiation, erythema and TEWL of the skin were both increased. The bound water content of the SC was also increased following UV irradiation. The NMF of the SC revealed different tendencies. All free amino acids (FAAs) of the NMF were increased after UV irradiation, except proline. trans-urocanic acid, pyrrolidone carboxylic acid, lactate, and urea, which are NMF components produced by the subsequent catabolism of FAAs and sweat, were decreased after UV irradiation. The amount of ceramide in the SC was also decreased after UV exposure, while cholesterol was increased. Conclusions: The bound water content of the SC was increased by UV exposure along with increasing TEWL, several NMF components, and cholesterol. These in vivo results for UV-damaged SC obtained via Raman spectroscopy could be applied to research with regard to protecting the SC from UV radiation and treating UV-damaged SC.

Cell responses to the impact of physiological doses of ultraviolet radiation and their modulation by plant polyphenols

In this study it was investigated the responses of cultured human cells – keratinocytes and fibroblasts to physiological doses of ultraviolet radiation (UVR) applied with or without plant polyphenolic compounds: rutin, quercetin, taxofolin, silybin and baikalein. Experimental data obtained in this work indicate the presence of synergism in the action of physiological doses of UVR and plant polyphenolic compounds on inflammatory signaling pathways in keratinocytes and fibroblasts. It is concluded that the identified synergies can contribute to the adaptation of the skin to subsequent exposure to UVR, and thus be one of the photoprotective mechanisms of the plant polyphenolic compounds.

Evaluating sunscreen ultraviolet protection using a polychromatic diffuse reflectance device.

BackgroundSun protection factor (SPF) and UVA protection factor (UVA‐PF) are determined using in vivo tests, with high exposures of subjects to ultraviolet (UV) radiation. Hybrid diffuse reflectance spectroscopy (HDRS) enables estimation of both indices using only trace amounts UVB. However, the equipment requires two expensive monochromators that must synchronously scan the spectrum.MethodsAn alternate approach was developed using a polychromatic source that illuminates the skin via a custom light guide array, and the diffuse reflected light is measured with a photomultiplier. The ratio of the diffuse reflectance with and without the sunscreen on the skin determines the polychromatic diffuse reflectance UVA‐PF (PDRS UVA‐PF0). This factor was used to adjust in vitro UV spectroscopy scans of the sunscreen (with and without UV exposure to assess photostability), to calculate SPF and UVA protection factors. Ten sunscreens were evaluated and compared to in vivo SPF and UVA‐PF values.ResultsThe data show an excellent correlation with known in vivo determinations.ConclusionThis polychromatic HDRS approach uses simpler, faster, and less expensive equipment to determine both UVA‐PF and SPFs without high doses of UV radiation to the test subjects.

Evaluation of a personalised adherence intervention to improve photoprotection in adults with Xeroderma Pigmentosum (XP): protocol for the trial of XPAND

IntroductionPoor adherence to photoprotection for people with xeroderma pigmentosum (XP) can be life-threatening. A randomised controlled trial (RCT) is being conducted to test the efficacy of a personalised adherence intervention...

Ultraviolet radiation sensors: a review.

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