Increased UV Exposure Research Articles

Increasing melanoma incidence with unchanged mortality: more sunshine, better treatment, increased diagnostic activity, overdiagnosis or lowered diagnostic threshold?

Increasing melanoma incidence with less increasing mortality is observed in several countries. This discrepancy is not well understood. In this study, our aim was to discuss factors [ultraviolet radiation (UVR) exposure, melanoma treatment, diagnostic activity, overdiagnosis, pathologists' diagnostic threshold and clinicians' propensity to remove suspect skin lesions] that might influence melanoma incidence and mortality in Denmark. This was a register study with the number of melanocyte-related lesions and melanoma mortality based on comprehensive national pathology and mortality databases for the period 1999-2019. We investigated melanocyte-related diagnoses and mortality in a population of 5.5 million with a national healthcare system. Age-adjusted melanoma mortality and age-adjusted incidence of benign naevi, atypical lesion, or melanoma in situ and of invasive melanoma were computed for data analysis. In total, 1 434 798 biopsies were taken from 704 682 individuals (65% female). The mean age at biopsy was 39.8 years in males and 37.6 in females. In males and females, the incidence of invasive melanoma increased by 87% during the period 1999-2011. During the subsequent period it increased by 9% in males but remained unchanged in females. The incidence of melanoma in situ increased by 476% in males and 357% in females during the study period, while the increases for atypical melanocytic lesions were 1928% and 1686%, respectively. Biopsy rates increased by 153% in males and 118% in females from 1999 through 2011 but fell by 20% in males and 22% in females during the subsequent period. Mortality varied slightly from year to year without any significant time trend for males or females. We identified no evidence of increased UVR exposure over the latest 30 years in Denmark. Immunotherapy of advanced melanoma was introduced in Denmark in 2010 and came into general use in 2014. Comprehensive national data demonstrate increasing melanoma incidence correlated with increasing biopsy rates, but with no change in mortality. Previously suggested explanations for such a trend are a lowered threshold of melanoma diagnosis among pathologists, increased diagnostic activity in the presence of overdiagnosis and improved melanoma treatment. Because the study is observational and we have more explanatory factors than outcomes, the findings do not warrant conclusions about causal relationships.

A UV-related risk analysis in ophthalmic malignancies: Increased UV exposure may cause ocular malignancies

PurposeTo explore the role of ultraviolet radiation (UVR) in the occurrence and development of various ocular malignancies. MethodsIn this article, we retrieved ocular malignancy data from the Global Cancer Observatory (GCO) and performed correlation analysis with the global UV index and sunshine duration. We searched for associated studies using the following databases: Embase, Pubmed, Cochrane Library, and Google Scholar. We conducted the literature by searching the Mesh terms denoting an exposure of interest ("UV radiation", "ultraviolet rays", and "ocular malignancies", All studies included are published until December 30, 2023 without language restrictions. ResultsThe mechanisms and epidemiological statistics of UVR on the onset and progression of eyelid malignancies are the most studied and clear. The role of UVR in conjunctival melanoma is similar to that in eyelid melanoma. The relationship between uveal melanoma and UVR is controversial, however, it may have at least a certain impact on its prognosis. UVR causes ocular surface squamous neoplasia by further activating HPV infection. ConclusionsUVR is a decisive risk factor for ocular malignancies, but the incidence of ultraviolet-induced tumors is also affected by many other factors. A correct and comprehensive understanding of the mechanisms of UVR in the pathogenesis of ocular malignant tumors can provide patients with more effective and selective immune regulation strategies.

UV-Induced Spectral and Morphological Changes in Bacterial Spores for Inactivation Assessment.

The ability to detect and inactivate spore-forming bacteria is of significance within, for example, industrial, healthcare, and defense sectors. Not only are stringent protocols necessary for the inactivation of spores but robust procedures are also required to detect viable spores after an inactivation assay to evaluate the procedure's success. UV radiation is a standard procedure to inactivate spores. However, there is limited understanding regarding its impact on spores' spectral and morphological characteristics. A further insight into these UV-induced changes can significantly improve the design of spore decontamination procedures and verification assays. This work investigates the spectral and morphological changes to Bacillus thuringiensis spores after UV exposure. Using absorbance and fluorescence spectroscopy, we observe an exponential decay in the spectral intensity of amino acids and protein structures, as well as a logistic increase in dimerized DPA with increased UV exposure on bulk spore suspensions. Additionally, using micro-Raman spectroscopy, we observe DPA release and protein degradation with increased UV exposure. More specifically, the protein backbone's 1600-1700 cm-1 amide I band decays slower than other amino acid-based structures. Last, using electron microscopy and light scattering measurements, we observe shriveling of the spore bodies with increased UV radiation, alongside the leaking of core content and disruption of proteinaceous coat and exosporium layers. Overall, this work utilized spectroscopy and electron microscopy techniques to gain new understanding of UV-induced spore inactivation relating to spore degradation and CaDPA release. The study also identified spectroscopic indicators that can be used to determine spore viability after inactivation. These findings have practical applications in the development of new spore decontamination and inactivation validation methods.

Risk analysis of systemic side effects of tumescent local anaesthesia in the surgical treatment of geriatric and multimorbid patients with skin cancer.

Due to demographic change and increased UV exposure, the number of dermatosurgical procedures in the elderly is increasing. Data on the occurrence of systemic side effects during and after treatment with tumescent local anaesthesia are limited and do not refer to details such as volume and composition of local anaesthetics or epinephrine additive. The aim of this study was to investigate the risk of systemic side effects in elderly patients undergoing skin tumour surgery with tumescent local anaesthesia. Investigation of systemic complications in patients (≥75 years) who underwent head and neck skin tumour surgery under tumescent local anaesthesia at the Department of Dermatology, University Medical Centre Tübingen, between October 2018 and March 2020. In total 782 patients (479 males, 303 females) with a mean age of 83.3 years (range: 75.1-102.2 years) could be included. A total of 2940 procedures were performed. Patients were assigned to two groups. The old-old group (≥75-84 years) included 491 patients and the oldest-old group (≥85 years) included 291 patients. The total inpatient stay and thus mean follow-up period was 4.9 days (range 1-28 days). 92.0% (719/782) suffered from pre-existing comorbidities. Systemic complications occurred in 10.2% (80/782; old-olds: 8.6%, oldest-olds: 13.1%). Hypertensive crisis (>180/120 mmHg) requiring intervention (6.7%) that occurred intraoperatively or during the inpatient stay was the most frequent systemic complication. Cardiac arrhythmias occurred postoperatively in 0.8% of cases. No life-threatening complications directly related to tumescent local anaesthesia were found. Skin tumour surgery in tumescent local anaesthesia for the elderly is safe, and complications caused by general anaesthesia can be avoided. Systemic complications can occur, but are usually mild, are caused by pre-existing diseases and perioperative excitement, and can be rapidly detected and well treated by monitoring. There is no direct correlation of complications to high-tumescent concentrations or volume quantities.

Long-term persistence and recycling of Bacillus thuringiensis israelensis spores in wetlands sprayed for mosquito control

Bacillus thuringiensis subsp. israelensis (Bti) is the main larvicide used to control mosquitoes worldwide. Although there is accumulating evidence of Bti having environmental effects on non-target fauna, relatively few field studies have documented the fate of Bti spores in the environment. Spore density was quantified over a 6-yr period (2012–2017) in Mediterranean marshes sprayed with Vectobac 12AS (32 ITU/ha) since 2006 to reduce the nuisance caused by Aedes caspius. Bti spores were naturally found in all habitat types. Spore density expressed as colony-forming units per gram of soil (CFU g−1) increased significantly at treated sites by a factor of 22 to 500 times relative to control sites, with mean values of 7730 CFU g−1 in halophilous scrubs, 38,000 in reed beds, 49,000 in bulrush beds and 50 000 in rush beds. Spore density varied little in the first months after the spraying season (April-October), but increased sharply in spring, just before the annual launch of mosquito control. Considering that Bti is an insect pathogen that cannot proliferate without a suitable insect host, this unexpected recrudescence in spring could be related to the warming of water that triggers activity and development of benthic organisms such as chironomids, which may contribute to Bti proliferation by ingesting accumulated spores at the surface of sediments. While spore density tends to decrease over time, presumably during the summer period as a result of increased UV exposure, three to four years were necessary for spore density to return to normal levels after mosquito-control interruption. This study is important because it demonstrates that environmental effects of mosquito-control using Bti can far exceed the short period of Bti efficacy against lentic mosquitoes. Considering that Bti is a microbial agent, these long-term effects should be addressed at multiple levels of ecosystem organization from a one-health perspective.

Photodegradation mechanisms and physico-chemical properties of EPON-IPD epoxy-based polymers

Shape memory polymers are increasingly being utilized in aviation and biomedical industries. However, full realization of their potential is limited due to the lack of mechanistic understanding of their environmental degradation. To address this issue, the chemical structure, thermo-mechanical, morphological, and optical properties of an epoxy-based shape memory polymer during UV-induced aging were studied using FTIR, DSC, nanoindentation and SEM techniques after exposure to UV radiation up to 600 h. The proposed mechanism involves competition between chain scission and crosslinking. SEM and DSC analysis confirmed that an increased UV exposure not only increases the number and dimension of microcracks on the surface but also increases the glass transition temperature (Tg) of epoxy-amine based polymer. Similarly, elastic modulus (E) and hardness (H) were increased by ~22 and 33%, respectively, after 600 h of UV radiation.

Contribution of family history of melanoma to associated risk factors: Analysis of an Internet-based risk assessment tool.

10546 Background: Risk factors for melanoma (ML) include UV exposure, sunburns, multiple nevi, and fair skin. Smoking and alcohol use may also play a role. Demographics associated with increased UV exposure include male gender, white race, age 18-29, and high-income. Those with family history (FH) of ML have increased risk of developing ML themselves yet are often unaware or do not engage in preventive behaviors. We sought to understand the association between FH of ML and other personal risk factors for cancer. Methods: Since 2009, voluntary participants could receive personalized information regarding their cancer risk via the OncoLink.org Reduce My Risk tool. Survey data was collected on demographics, FH, risk-factors, and risk-associated behaviors. Use of data was IRB approved. Differences between respondents with v. without FH of ML were analyzed using chi-square test and adjusted via logistic regression. Results: 25255 responses were analyzed; 1928 (7.6%) had FH of ML. Of these, median age was 26 (range 18-75), 73.1% were female, 88.6% from North America, 91.4% White, 78.2% had at least some college, and 62.0% household income > $45,000. Comparing those with FH of ML to those without, no significant differences were observed in education, income, or home setting. Those with a FH of ML were less likely to be “light” smokers ( < 1 pack per day) but were more likely to be both “light” drinkers and “heavy” drinkers (Table). There were no significant differences in BMI or exercise habits. Those with FH of ML were more likely to sunbathe, to have had “blistering” sunburns, have 50+ moles, show signs of sun damage on their skin, and have dysplastic nevi (Table). There were no differences in use of indoor tanning beds (Table). Conclusions: Those with a FH of ML were more likely to sunbathe and to report skin damage and history of blistering sunburns; they were more likely to use tanning beds, though not statistically significant. These behaviors are modifiable and may suggest parental influence on sun-protective behaviors. Those with FH also reported increased non-modifiable risks. Future work should continue to explore targeted intervention for those with a FH of ML to educate on risk and promote sun-protective behaviors.[Table: see text]

Tanning Attitudes and Behaviors in Adolescents and Young Adults.

Skin cancer rates have been steadily increasing over the last 20 years despite persistent efforts to educate the public on skin cancer prevention and sun safety. Adolescents and young adults are an especially important demographic to reach, as increased UV exposure during these years leads to greatly increased risks of developing skin cancer. Our survey aims to investigate the attitudes and behaviors regarding sun protection and tanning among adolescents and young adults (age range, 13-27 years).

What Are the Options Beyond SPF 50+? A View on Consumer Behavior and the Sensory Features of Sunscreens.

Skin cancer rates have been on the rise for decades and are still growing in spite of the availability of high-performance sunscreens that provide sufficient protection against the damaging effect of UV radiation everywhere on this globe. This paper investigates behaviors and attitudes to sunscreen use that may cause an increased UV exposure risk, for example, not using sunscreen at all. Alongside educational reasons, there is a link to some aspects of applying sunscreens that seem to be disliked universally. Therefore, the sensory features of 73 globally sourced commercial sunscreens were measured using quantitative descriptive sensory analysis. This revealed the ranges of sensory intensity currently available, which were then compared with what consumers really want, and showed that only a few sunscreens currently fulfill the needs of people in the most abundant consumer group - "dry touch seekers." All this contributes to insufficient or no use at all of sunscreens during sun exposure, which could result in significant UV dosages that turn out to be relevant for skin cancer development. A more integral approach to improving sunscreen formulas, along with more targeted communication to connect more effectively with consumers who currently show those avoidance behaviors, is needed.

A descriptive observational study on clinical and dermoscopic features of benign melanocytic neoplasms.

Benign melanocytic neoplasms have nests of melanocytic cells and show characteristic dermoscopic features. Clinical and dermoscopic features have not been studied previously in the Indian population. To study the clinical, epidemiological and dermoscopic patterns of benign melanocytic neoplasms. This was a descriptive, observational, single centre study. In 107 patients with melanocytic neoplasms, 167 lesions were clinically examined and studied under the dermoscope and histopathological examination was done when indicated. The lesions were broadly divided as acquired and congenital. Five main dermoscopic patterns were seen-globular, homogenous, reticular, parallel and streaks. If there were two of these patterns in a particular lesion, it was termed 'mixed pattern'. The presence of three or more patterns was called 'multicomponent pattern'. Various other features were also observed. The majority of patients belonged to the third decade with a female preponderance. History of increased UV exposure and family history was significant in acquired nevi. The dermoscopic pattern progressed from predominantly reticular in junctional nevi to predominantly globular in compound nevi and lesser pigment in intradermal nevi, with more vascular structures. The congenital melanocytic nevi showed additional features of comedo- like lesions, milia- like cysts, perifollicular pigmentary changes and increased colour variation. Even though colour variation was observed in both acquired and congenital lesions, no signs of dysplasia were seen on histopathology. A larger sample size is required, with follow up of lesions. No parallel studies in brown skinned population were found for exact comparison. Benign melanocytic proliferations are often neglected in our country. This study will help in understanding the course, clinical features and dermoscopic patterns of various benign melanocytic neoplasms, and will be a step forward towards research in our population. To the best of our knowledge, this is the first study of its kind in India.

Paediatric melanoma.

Paediatric melanoma, although rare, is the most common skin cancer in children. Our current knowledge on paediatric melanoma incidence trends is expanding, as several studies have addressed this issue with conflicting results. Known risk factors for paediatric melanoma include family history of melanoma, a previous history of malignancy, large congenital nevi, numerous melanocytic nevi, sunburns, increased UV exposure and a sun-sensitive phenotype. In younger children, melanoma more often presents with atypical features, such as a changing, amelanotic or uniformly coloured, often bleeding lesion, not fulfilling in most cases the conventional ABCDE criteria. The major differential diagnoses are melanocytic nevi, proliferative nodules in congenital nevi and atypical Spitz tumours. Moreover, in the younger age group non-Caucasian children are over-represented, tumours tend to be thicker and lymph nodes are often involved. Despite the frequent diagnosis at an advanced stage, the overall survival is fair in paediatric melanoma. Specific guidelines for management of melanoma in children do not exist, and most often the disease is treated similarly to melanoma in adults.

Skin Cancer and Its Correlates: A Study of Knowledge and Preventive Behavior in Riyadh

Background: Worldwide, the incidence of skin cancer has increased due to increased UV exposure to solar and artificial sources. In Saudi Arabia, skin cancer ranked the 9th most common cancer for both sexes. However, it is considered to be a preventable disease. WHO has proposed several preventive methods to avoid the damaging effects of excessive exposure to UV rays including; social education and adopting positive behavioral changes. The present study aimed to evaluate the level of knowledge, attitudes and behaviors of people in Riyadh city towards skin cancer. Results: The mean respondent's age was 35 years (12-65 years). Females represented about two-thirds of the 341 respondent. A statistically significant associations were detected between awareness about skin cancer with the age (Beta =0.03, p =0.047), educational level (Beta =0.63, p =0.042) and skin color (Beta =-2.14, p<0.001) being significant predictors for disease. Conclusions: To our knowledge, this was the first study to assess the level of knowledge, attitudes, and practices regarding skin cancer in Saudi Arabia. Despite the limitations, the present study’s findings suggested that Saudis lack the sufficient knowledge to understand and assess the importance of skin cancer risk. In addition, the level of knowledge, attitude and behaviors are influenced by several factors as age, education level and skin color.

UVB damages treefrog tadpole DNA

![Figure][1] Montevideo treefrog tadpoles under UV-free visible light. Photo credit: Andre Schuch. Ever since the blanket of ozone that protects the planet from hazardous UV radiation began to dwindle, there have been concerns about the risks of increased UV exposure. And humans are not

Automobile In Environment

In our daily busy life; automobile has changed our experience of journey. It has made very fast, comfortable and easy. On the other hand we have mixed the toxic in our environment. Some has come from industries and some of from the pumping and showing world. Some is necessary and some is not. But the common part of both is automobile As it is luxurious as necessary requirement also according to the time In our environment the automobile has provided hazardous gases and improve the temperature of our environment which all the root of disease. The temperature is also caused of global warming which is impact on ozone layer depletion. Ozone layer prevents most harmful UVB wavelengths (280–315 nm) of ultraviolet light (UV light) from passing through the Earth’s atmosphere. It is suspected that a variety of biological consequences such as increases in skin cancer, cataracts, damage to plants, and reduction of plankton populations in the ocean’s photic zone may result from the increased UV exposure due to ozone depletion. As a matter of fact, this layer very important for saving of human being. But due to increasing pollution. The average size of the 2012 ozone hole was 6.9 million square miles (17.9 million square kilometres). There is not end of all this, with this all. There we can realize there many changes in our ambient system. We have to face a lot of problems due to natural disaster. There more than 50% day in year when we have to face many disasters like earthquake, glacier melting, tsunamis etc. Due to the unbalance environment there is very big difficulty that we can’t delay our progressive life. But we have to solve this problem; we take many steps to save our environment. With the results, we can increase the time of party and natural facilities gifted by God. For this we can use many technology which in favour of environment.

Increased Ultraviolet Light Exposure is Associated With Reduced Risk of Inpatient Surgery Among Patients With Crohn’s Disease

Due to the formation of strictures and fistulas, patients with Crohn's disease (CD) frequently need surgery. Vitamin D has been found to play a role in the degree of inflammation. We aimed to study the effect of UV exposure on the need for inpatient surgery in patients with CD. The national inpatient sample, the largest database of hospitalizations from the USA, was used to conduct a retrospective study of patients hospitalized from 2004-2011 with CD by ICD-9CM code 555. Surgery was characterized as any intestinal surgery or fistula repair. An average state UV exposure was calculated for each hospitalization. Multivariate logistic regression was used to calculate the effect of UV exposure on surgery accounting for important covariates. There were 481712 hospitalizations with a primary diagnosis of CD. Of these hospitalizations, 67751 included a relevant surgical procedure code. Mean UV exposure was statistically lower in the group undergoing surgery (4.3 units versus 4.4 units, p = 0.001). The ratio of hospitalizations per UV exposure tertile for CD was statistically different compared with all hospitalizations (p < 0.001). In univariate analysis, increased UV exposure was associated with a lower risk of inpatient surgery with an OR of 0.90 per unit (95% CI 0.84-0.96, p = 0.001). Accounting for age, gender, race/ethnicity, season, income, hospital setting, and Charlson-Deyo comorbidities, the effect of UV exposure remained protective for inpatient surgery (OR 0.91, 95% CI: 0.84-0.98, p = 0.01). Increased UV exposure is associated with a reduced risk of inpatient surgery among patients with CD. Further studies of vitamin D's role in CD are necessary.

New Aspects of Melasma/Novi aspekti melazme

Abstract Melasma is a common cosmetic problem and its severity ranges from minor pigmentation during pregnancy that resolves spontaneously, to a chronic, troublesome, disfiguring condition. Today, there are various treatment modalities for melasma, providing a different success rate. The need for an effective treatment for melasma is becoming more and more significant probably due to the current lifestyles with increased UV exposure, broad use of hormones for contraception and hormone replacement therapy, as well as increasing esthetic demands. The mainstay of treatment is regular use of sunscreens along with topical medications suppressing melanogenesis. This review summarizes recent progress in understanding the pathophysiology of melasma and implications for new treatment strategies.

Climatic Factors Are Associated with Childhood Eczema Prevalence in the United States

Atopic dermatitis (AD, atopic eczema) is driven by a complex relationship between genetic predisposition and environmental exposures. We sought to determine the impact of specific climatic factors on the US prevalence of AD. We used a merged analysis of the 2007 National Survey of Children's Health from a representative sample of 91,642 children age 0–17 years and the 2006–2007 National Climate Data Center and Weather Service measurements of relative humidity (%), indoor heating degree days (HDD), clear sky UV indices ozone levels, and outdoor air temperature. As a proxy for AD, we used an affirmative response to the NSCH survey question asking whether the participant’s child has been given a doctor diagnosis of “eczema or any other kind of skin allergy” in the previous 12 months. In multivariate models controlling for sex, race/ethnicity, age and household income, eczema prevalence was significantly lower with highest-quartile mean annual relative humidity (logistic regression, adjusted odds ratio [95% confidence interval]=0.82 [0.71–0.96], P=0.01) and issued UV index (0.73 [0.64–0.84], P<0.0001), and with two other factors associated with increased UV exposure. Eczema prevalence was decreased with highest-quartile air temperature (0.80 [0.70–0.92], P=0.002), but increased with 3rd–quartile mean annual HDD (1.26 [1.11–1.43], P=0.0003). This study provides evidence of climate influences on the US prevalence of childhood eczema.

Hyperpigmentary disorders: a therapeutic challenge in the dermatological practice

Hyperpigmentary disorders have an increasing prevalence in the dermatological practice. This is based on the recent common life style with increased UV exposure and broad usage of hormones for contraception or hormone replacement therapy. In addition a democratization of cosmetic procedures leads to higher risk to develop post-inflammatory hyperpigmentation. Therapeutic challenges for hyperpigmentation disorders occur as a result of the highly individualized condition of each patient, the treatment resistance of hyperpigmented lesions, the high prevalence of reappearance and the necessity to balance between effective treatment and a low risk of adverse events. The individuality of each case which results out of an individually associated cause and clinical type of hyperpigmentation requires that medical professionals have a deep knowledge in hyperpigmentation causalities and therapy options. Resistance to treatments and the high prevalence of reappearance demand an individual combination of long-term treatment options which focus not only on an initial bleaching but also on a persistent depigmentation. A multitude of professional procedures, technical devices and topical agents are used with different outcomes where the expected result is not always predictable. This challenges not only the medical professional but also the compliance of the patient. In addition, the expectation to show immediate and longlasting depigmentation without adverse events such as post-inflammatory hyperpigmentation, confronts the dermatologist with a huge responsibility and pressure in his daily work. New research findings show that there are even more factors playing a role in the pathogenesis of hyperpigmentation, which are not considered in current treatment options. Nevertheless, there is one commonality in each hyperpigmented lesion independent of cause and clinical type: increased levels of melanin because of increased activity of the human enzyme tyrosinase. This suggests one key treatment option: the inhibition of tyrosinase.

Design and examination of an antioxidant-containing polyphosphazene scaffold for tissue engineering

Polyphosphazenes were synthesized that contained the antioxidant, ferulic acid, and amino acid esters as co-substituents. The synthesis protocol utilized the replacement of chlorine atoms in poly(dichlorophosphazene) by ferulic acid with either glycine, alanine, valine, or phenylalanine ethyl ester. Ferulic acid protects cells from free radical damage, and its steric characteristics have the potential to generate polymeric materials with high mechanical strength for hard tissue engineering scaffolds. Incorporation of the amino acid esters allows for control over the polymer hydrolysis while releasing the antioxidant at different rates. Macromolecular substitution reactions were carried out utilizing the allyl ester of ferulic acid to prevent side reactions during halogen replacement. The allyl protecting group was then removed using mild conditions. The polymers were characterized by 1H and 31P NMR, GPC, and DSC techniques. Static water contact angles were measured to monitor the change in hydrophobicity/hydrophilicity. Before deprotection, the water contact angles were 82–88° and after deprotection the water contact angles were 56–71°. A pH-dependent hydrolysis study revealed that the polymers are hydrolytically sensitive and decomposed ∼5–25% over 8 weeks yielding a final pH between 6.0–6.8. Polymer hydrolysis resulted in the release of ferulic acid. The polymers were photocrosslinked by a [2 + 2] cycloaddition of the ferulic acid moieties induced by exposure to long-wave UV light. The crosslinking was monitored by UV-spectroscopy via the apparent decrease in the 320 nm absorbance, attributed to the cyclization of the ferulic acid moieties. Increased UV exposure time led to an increase in the level of crosslinking. After 60 s, the polymers were crosslinked ∼41–62%. Hydrolysis experiments of the crosslinked materials showed only a 0–5% weight loss after 8 weeks with a pH between 6.6–7.0.

Does increased sunlight exposure work as a strategy to improve vitamin D status in the elderly: a cluster randomised controlled trial

Sunlight exposure by improving vitamin D status could be a simple public health strategy in reducing falls among frail elder people. In a randomised controlled trial, adherence to sunlight exposure was low (median adherence, 26%) and no effect of increased UV exposure on falls risk was observed (incidence rate ratio (IRR) 1.06, P = 0.73). This study aimed to determine whether increased sunlight exposure was effective to improve vitamin D status and reduce falls in the elderly. In a cluster randomised controlled trial (NCT00322166 at ClinicalTrials.gov), 602 residents aged 70 or more (mean age, 86.4 years; 71% female) were recruited from 51 aged care facilities in Northern Sydney, Australia. Participants were randomised by facility to receive either increased sunlight exposure (additional 30-40 min/day in the early morning) with (UV+) or without (UV) calcium supplementation (600 mg/day) or neither (control) for a year. The co-primary endpoints were change in serum 25 hydroxy vitamin D (25OHD) and falls incidence after 12 months. Adherence to sunlight exposure was low (median adherence, 26%; IQR, 7%-45%). Serum 25OHD levels were low at baseline (median, 32.9 nmol/L) and increased only slightly depending on the number of sunlight sessions attended over 12 months (P = 0.04). During the study, 327 falls occurred in 111 (54%) subjects in the control group, 326 falls in 111 (58%) subjects in the UV only group and 335 falls in 108 (52%) subjects in the UV+ group. By intention-to-treat analysis, there was no significant effect of increased UV exposure on falls risk (IRR, 1.06; 95% CI, 0.76-1.48; P = 0.73). However, in 66 participants who attended ≥130 sessions per year (adherence, ≥50% of 260 sessions-five per week), falls were significantly reduced (IRR, 0.52; 95% CI, 0.31-0.88; P = 0.01) compared with the control group. Increased sunlight exposure did not reduce vitamin D deficiency or falls risk in frail older people. This public health strategy was not effective most likely due to poor adherence to the intervention.