UV doses of American children and adolescents

Assessment of UV Protection for Children's Summer Clothing

INTRODUCTION

 Excess ultraviolet (UV) radiation exposure during childhood poses a particular long-term risk of developing skin cancer later in life however recent studies have called attention to the absorption of chemical sunscreen ingredients into the bloodstream with unclear significance. This has led to recommendations to consider sun protection in the form of clothing to reduce the need for sunscreen products.

METHODS

 Ten brands of routine summer clothing not labeled as sun protective from five distributors marketed for children were identified with varying price ranges. Summer clothing items consisting of T-shirts and tops were evaluated for fiber composition, cost, and UPF testing was performed to determine UVA and UVB transmittance.  Results: Around 88.2% of blended textile compositions compared to 60% of 100% cotton textiles offered adequate UV protection with an Ultraviolet Protection Factor (UPF) greater than 15. 58% of blended fabrics compared to 50% of cotton textiles offered a UPF greater than 30. There was no correlation between brand and cost with UPF values.  Conclusions: In the absence of regulations for testing and labeling of all children's garments for UV protection, guidelines for the pediatric population for choosing clothing for the summer should reflect the information available to consumers that is easy to understand and more likely to result in higher UPF values. Based on fiber composition, blended textiles are more likely to have adequate UV protection compared to 100% cotton or 100% polyester.

Photokeratitis induced by ultraviolet radiation in travelers: A major health problem

Ultraviolet (UV) irradiation is one of the several environmental hazards that may cause inflammatory reactions in ocular tissues, especially the cornea. One of the important factors that affect how much ultraviolet radiation (UVR) humans are exposed to is travel. Hence, traveling is considered to include a more acute UVR effect, and ophthalmologists frequently evaluate and manage the ocular manifestations of UV irradiation, including UV-induced keratitis. The purpose of this paper is to provide an evidence-based analysis of the clinical effect of UVR in ocular tissues. An extensive review of English literature was performed to gather all available articles from the National Library of Medicine PubMed database of the National Institute of Health, the Ovid MEDLINE database, Scopus, and ScienceDirect that had studied the effect of UVR on the eye and its complications, between January 1970 and June 2014. The results show that UVR at 300 nm causes apoptosis in all three layers of the cornea and induces keratitis. Apoptosis in all layers of the cornea occurs 5 h after exposure. The effect of UVR intensity on the eye can be linked to numerous factors, including solar elevation, time of day, season, hemisphere, clouds and haze, atmospheric scattering, atmospheric ozone, latitude, altitude, longitudinal changes, climate, ground reflection, and geographic directions. The most important factor affecting UVR reaching the earth's surface is solar elevation. Currently, people do not have great concern over eye protection. The methods of protection against UVR include avoiding direct sunlight exposure, using UVR-blocking eyewear (sunglasses or contact lenses), and wearing hats. Hence, by identifying UVR intensity factors, eye protection factors, and public education, especially in travelers, methods for safe traveling can be identified.

Obesity is associated with vitamin D deficiency in Danish children and adolescents

BACKGROUND

Sufficient serum concentrations of vitamin D are required to maintain bone health during growth. The aims of this study were to determine whether vitamin D deficiency is more prevalent among children and adolescents with obesity compared to their normal weight peers and to identify clinical and biochemical variables associated with vitamin D deficiency.

METHODS

One thousand four hundred and eighty-four children and adolescents with overweight/obesity and 2143 population-based controls were recruited from the Danish Childhood Obesity Biobank. Anthropometric variables and fasting concentrations of serum 25-hydroxy vitamin D (25-OH-D), plasma parathyroid hormone (PTH), calcium and phosphate were assessed at baseline. Vitamin D deficiency was defined as serum 25-OH-D concentrations <30 nmol/L. Linear and logistic regressions were used to identify variables associated with vitamin D deficiency.

RESULTS

A total of 16.5% of the children and adolescents with obesity (body mass index [BMI] standard deviation score [SDS]>2.33) exhibited vitamin D deficiency, with an odds ratio (OR) 3.41 (confidence interval [CI]: 2.27-5.71; p<0.0001) for being vitamin D deficient compared to their normal weight peers. BMI-SDS was independently and inversely associated with serum 25-OH-D concentrations. Other independent risk factors for vitamin D deficiency were being older than 14 years (OR: 2.39; CI: 1.28-4.48; p=0.006), more than 4 daily hours of screen time (OR: 4.56; CI: 2.59-8.05; p<0.0001) and blood sample assessment during winter-spring (OR: 6.44; CI: 4.47-9.26; p<0.0001).

CONCLUSIONS

Vitamin D deficiency was common among Danish children and adolescents with obesity. The degree of obesity was independently associated with lower serum 25-OH-D concentrations.

Loss of Genome Fidelity: Beta HPVs and the DNA Damage Response

While the role of genus alpha human papillomaviruses in the tumorigenesis and tumor maintenance of anogenital and oropharyngeal cancers is well-established, the role of genus beta human papilloviruses (β-HPVs) in non-melanoma skin cancers (NMSCs) is less certain. Persistent β-HPV infections cause NMSCs in sun-exposed skin of people with a rare genetic disorder, epidermodysplasia verruciformis. However, β-HPV infections in people without epidermodysplasia verruciformis are typically transient. Further, β-HPV gene expression is not necessary for tumor maintenance in the general population as on average there is fewer than one copy of the β-HPV genome per cell in NMSC tumor biopsies. Cell culture, epidemiological, and mouse model experiments support a role for β-HPV infections in the initiation of NMSCs through a "hit and run" mechanism. The virus is hypothesized to act as a cofactor, augmenting the genome destabilizing effects of UV. Supporting this idea, two β-HPV proteins (β-HPV E6 and E7) disrupt the cellular response to UV exposure and other genome destabilizing events by abrogating DNA repair and deregulating cell cycle progression. The aberrant damage response increases the likelihood of oncogenic mutations capable of driving tumorigenesis independent of a sustained β-HPV infection or continued viral protein expression. This review summarizes what is currently known about the deleterious effects of β-HPV on genome maintenance in the context of the virus's putative role in NMSC initiation.

Sun Safety Practices Among Schools in the United States

Importance

Exposure to the sun's UV radiation is a leading cause of skin cancer. Positive attitudes and beliefs about sun safety behavior, which would make sun protective behavior more likely, could be promoted and supported by school policies and practices.

Objective

To identify school characteristics associated with having adopted practices that promote sun safety.

Design, Setting, and Participants

School-level data from the February 3 to July 23, 2014, School Health Policies and Practices Study's Healthy and Safe School Environment questionnaire were analyzed. The School Health Policies and Practices Study uses a 2-stage sampling design to select a nationally representative sample of schools. All public, state-administered, Catholic, and non-Catholic private schools with any of the grades from kindergarten through 12 were eligible for inclusion. All analyses were conducted using weighted data.

Main Outcomes and Measures

Prevalence of sun safety practices.

Results

In a nationally representative sample of 828 US schools, representatives of 577 schools (69.7%) responded. Overall, sun safety practices were not common among schools. The most frequent practice was having teachers allow time for students to apply sunscreen at school (47.6%; 95% CI, 42.4%-52.9%). Few schools made sunscreen available for students to use (13.3%; 95% CI, 10.2%-17.0%), almost always or always scheduled outdoor activities to avoid times when the sun was at peak intensity (15.0%; 95% CI, 11.4%-19.6%), or asked parents to ensure that students applied sunscreen before school (16.4%; 95% CI, 12.9%-20.6%). High schools were less likely than elementary schools and middle schools to adopt several practices: for instance, 37.5% of high schools (95% CI, 29.7%-46.0%), 51.6% of middle schools (95% CI, 43.3%-59.7%), and 49.5% of elementary schools (95% CI, 42.0%-57.0%) had teachers allow time for students to apply sunscreen at school, and 11.8% of high schools (95% CI, 7.7%-17.5%), 18.2% of middle schools (95% CI, 13.3%-24.4%), and 14.7% of elementary schools (95% CI, 9.6%-21.8%) almost always or always scheduled outdoor activities to avoid times when the sun was at peak intensity. Other school characteristics were either not significantly associated with the adoption of any of the sun safety school practices studied (eg, metropolitan status) or were inconsistently associated with such policies and practices (eg, region, percentage of students eligible for free or reduced-price lunch, and school enrollment).

Conclusions and Relevance

School practices that could protect children and adolescents from sun exposure and that could change norms about sun safety are not common. Interventions aimed at increasing the adoption of sun safety practices among schools are needed regardless of the level, location, size, and poverty concentration of the school. Such practices would cost little to implement and would support other messages targeted toward children, adolescents, adults, and parents, with an aim to reduce skin cancer morbidity and mortality.

High Prevalence of Vitamin D Insufficiency in Farming and Nonfarming Populations in South Dakota: Associations With Parathyroid Hormone, Body Fat, and Bone Density

The purpose of this study was to investigate the role of lifestyle (farming vs nonfarming), age, season, and percent body fat on serum 25-hydroxyvitamin D (25-OHD) and parathyroid hormone (PTH). Serum 25-OHD concentrations were lower in winter than in summer and in older than in younger individuals. Dietary intake of vitamin D was associated with greater serum 25-OHD concentrations. A significant inverse relationship between PTH and 25-OHD was observed in older but not younger individuals. Trabecular volumetric bone mineral density was inversely associated with serum PTH, but not 25-OHD concentrations. Modern farm practices do not necessitate excessive sunlight exposure and that may help explain the lack of differences between farming and nonfarming populations.

Vitamin D status and its determinants during autumn in children at northern latitudes: a cross-sectional analysis from the optimal well-being, development and health for Danish children through a healthy New Nordic Diet (OPUS) School Meal Study

Sufficient summer/autumn vitamin D status appears important to mitigate winter nadirs at northern latitudes. We conducted a cross-sectional study to evaluate autumn vitamin D status and its determinants in 782 Danish 8-11-year-old children (55°N) using baseline data from the Optimal well-being, development and health for Danish children through a healthy New Nordic Diet (OPUS) School Meal Study, a large randomised controlled trial. Blood samples and demographic and behavioural data, including 7-d dietary recordings, objectively measured physical activity, and time spent outdoors during school hours, were collected during September-November. Mean serum 25-hydroxyvitamin D (25(OH)D) was 60·8 (sd 18·7) nmol/l. Serum 25(OH)D levels ≤50 nmol/l were found in 28·4 % of the children and 2·4 % had concentrations <25 nmol/l. Upon multivariate adjustment, increasing age (per year) (β -2·9; 95 % CI -5·1, -0·7 nmol/l), female sex (β -3·3; 95 % CI -5·9, -0·7 nmol/l), sampling in October (β -5·2; 95 % CI -10·1, -0·4 nmol/l) and November (β -13·3; 95 % CI -17·7, -9·1), and non-white ethnicity (β -5·7; 95 % CI -11·1, -0·3 nmol/l) were negatively associated with 25(OH)D (all P<0·05). Likewise, immigrant/descendant background was negatively associated with 25(OH)D, particularly in females (β -16·3; 95 % CI -21·9, -10·7) (P<0·001) (P interaction=0·003). Moderate-to-vigorous physical activity (MVPA) (min/d) (β 0·06; 95 % CI 0·01, 0·12), outdoor walking during school hours (min/week) (β 0·4; 95 % CI 0·1, 0·6) and intake of vitamin D-containing supplements ≥3 d/week (β 8·7; 95 % CI 6·4, 11·0) were positively associated with 25(OH)D (all P<0·05). The high proportion of children with vitamin D status below the recommended sufficiency level of 50 nmol/l raises concern as levels expectedly drop further during winter months. Frequent intake of vitamin D supplements was strongly associated with status. MVPA and outdoor activity during school hours should be investigated further in interventions to improve autumn vitamin D status in children at northern latitudes.

Exponentially increasing incidences of cutaneous malignant melanoma in Europe correlate with low personal annual UV doses and suggests 2 major risk factors

For several decades the incidence of cutaneous malignant melanoma (CMM) steadily increased in fair-skinned, indoor-working people around the world. Scientists think poor tanning ability resulting in sunburns initiate CMM, but they do not understand why the incidence continues to increase despite the increased use of sunscreens and formulations offering more protection. This paradox, along with lower incidences of CMM in outdoor workers, although they have significantly higher annual UV doses than indoor workers have, perplexes scientists. We found a temporal exponential increase in the CMM incidence indicating second-order reaction kinetics revealing the existence of 2 major risk factors. From epidemiology studies, we know one major risk factor for getting CMM is poor tanning ability and we now propose the other major risk factor may be the Human Papilloma Virus (HPV) because clinicians find β HPVs in over half the biopsies. Moreover, we uncovered yet another paradox; the increasing CMM incidences significantly correlate with decreasing personal annual UV dose, a proxy for low vitamin D3 levels. We also discovered the incidence of CMM significantly increased with decreasing personal annual UV dose from 1960, when it was almost insignificant, to 2000. UV and other DNA-damaging agents can activate viruses, and UV-induced cytokines can hide HPV from immune surveillance, which may explain why CMM also occurs in anatomical locations where the sun does not shine. Thus, we propose the 2 major risk factors for getting CMM are intermittent UV exposures that result in low cutaneous levels of vitamin D3 and possibly viral infection.

Solar UV doses of young Americans and vitamin D3 production

BACKGROUND

Sunlight contains ultraviolet B (UVB) radiation (290-315 nm) that affects human health in both detrimental (skin cancers) and beneficial (vitamin D3) ways. Serum 25-hydroxyvitamin D concentrations from young Americans (≤ 19 years) show that many have deficient (< 50 nmol/L, 20 ng/mL) or insufficient (< 75 nmol/L, 30 ng/mL) vitamin D levels, indicating that they are not getting enough sun exposure. Those findings are in conflict with some calculated, published values that suggest people make "ample" vitamin D3 (~ 1,000 IU/day) from their "casual," or everyday, outdoor exposures even if they diligently use sunscreens with sun protection factor (SPF) 15.

OBJECTIVE

We estimated how much vitamin D3 young Americans (n = ~ 2,000) produce from their everyday outdoor ultraviolet doses in the North (45°N) and South (35°N) each season of the year with and without vacationing.

METHODS

For these vitamin D3 calculations, we used geometric conversion factors that change planar to whole-body doses, which previous calculations did not incorporate.

RESULTS

Our estimates suggest that American children may not be getting adequate outdoor UVB exposures to satisfy their vitamin D3 needs all year, except some Caucasians during the summer if they do not diligently wear sunscreens except during beach vacations.

CONCLUSION

These estimates suggest that most American children may not be going outside enough to meet their minimal (~ 600 IU/day) or optimal (≥ 1,200 IU/day) vitamin D requirements.

A cluster randomized trial of sun protection at elementary schools. Results from year 2

BACKGROUND

Elementary schools are one potential venue for sun protection interventions that reduce childhood sun exposure.

PURPOSE

To assess Year-2 results from a cluster randomized trial promoting hat use at schools.

DESIGN

Block randomization was used to assign intervention/control status to participating schools. Data were collected from 2006 to 2008 and analyzed in 2007-2010.

SETTING/PARTICIPANTS

Of the 24 schools in the School District of Hillsborough County, Florida enrolled, 4th-graders were targeted in the first year and followed through their 5th-grade year.

INTERVENTION

Classroom sessions were conducted to improve sun protection knowledge, foster more positive attitudes about hat use, and change the subjective norm of wearing hats when at school.

MAIN OUTCOME MEASURES

Year-2 outcomes assessed included hat use at school (measured by direct observation), hat use outside of school (measured by self-report) and skin pigmentation and nevi counts (measured for a subgroup of 439 students).

RESULTS

The percentage of students observed wearing hats at control schools remained unchanged during the 2-year period (range 0%-2%) but increased significantly at intervention schools (2% at baseline, 41% at end of Year 1, 19% at end of Year 2; p<0.001 for intervention effect). Measures of skin pigmentation, nevi counts, and self-reported use of hats outside of school did not change during the study period.

CONCLUSIONS

This intervention increased use of hats at school through Year 2 but had no measurable effect on skin pigmentation or nevi. Whether school-based interventions can ultimately prevent skin cancer is uncertain.

Solar UV doses of adult Americans and vitamin D(3) production

BACKGROUND

Sunlight contains UV radiation that affects human health in both detrimental (skin cancers) and beneficial (vitamin D(3)) ways. An evaluation of the vitamin D status of adult Americans (22-40, 41-59, 60+ yr) show many have deficient or insufficient serum levels of 25-hydroxyvitamin D, indicating they are not getting enough from dietary sources or sunlight. Those findings are in conflict with calculated values from the American Academy of Dermatology who insist people make "ample" vitamin D(3) (≥1,000 IU/day) from their "casual," or everyday, outdoor UV exposures even if they use sunscreens with sun protection factor 15.

OBJECTIVE

We investigated this situation using the everyday outdoor UV doses of indoor-working adult Americans (∼7,000) in the north (45°N) and south (35°N) to calculate how much vitamin D(3) they produce each season with and without vacationing.

RESULTS

Only during the summer can skin type II Caucasian adults (21-59 yr) meet their minimum (600 IU/day) vitamin D(3) needs from everyday exposures, but only if they do not wear professional clothes or sunscreens (except beach vacations).

METHOD

To do vitamin D(3) calculations properly, we used action spectrum and geometric conversion factors, not previously incorporated into other calculations.

CONCLUSIONS

Most adult Americans do not go outside enough to meet their minimum or optimum (≥1,200 IU/day) vitamin D(3) needs all year. The darker skin types (III-VI) and the oldest people (>59 yr) are at the highest risk for not making enough vitamin D(3) during the year from everyday outdoor exposures even with a 2-3 week summer vacation.

New insights about infant and toddler skin: implications for sun protection

The skin is increasingly recognized as a component of the innate immune response, in addition to its role as a physical barrier. Although the deleterious effects of solar ultraviolet radiation (UVR), including immunosuppression and cutaneous tumorigenesis, are widely acknowledged, most studies to date have concentrated on adult skin. Despite the more sensitive nature of infant and toddler skin, little is known about its responses to UVR exposure, whether acute or long-term. Accumulating evidence suggests not only that the skin's barrier protection remains immature throughout at least the first 2 years of life but also that accumulation of UVR-induced changes in the skin may begin as early as the first summer of life. Such evidence not only affirms the importance of sun protection during the infant and toddler years but underscores the need for more research to establish evidence-based standards of care in this area. In this article we review recent studies in which differences between the skin properties of infants and young children and those of adults were compared, and we discuss the implications of these differences for sun-protection practices.

Green tea prevents non-melanoma skin cancer by enhancing DNA repair

Excessive exposure of the skin to solar ultraviolet (UV) radiation is one of the major factors for the development of skin cancers, including non-melanoma. For the last several centuries the consumption of dietary phytochemicals has been linked to numerous health benefits including the photoprotection of the skin. Green tea has been consumed as a popular beverage world-wide and skin photoprotection by green tea polyphenols (GTPs) has been widely investigated. In this article, we have discussed the recent investigations and mechanistic studies which define the potential efficacy of GTPs on the prevention of non-melanoma skin cancer. UV-induced DNA damage, particularly the formation of cyclobutane pyrimidine dimers, has been implicated in immunosuppression and initiation of skin cancer. Topical application or oral administration of green tea through drinking water of mice prevents UVB-induced skin tumor development, and this prevention is mediated, at least in part, through rapid repair of DNA. The DNA repair by GTPs is mediated through the induction of interleukin (IL)-12 which has been shown to have DNA repair ability. The new mechanistic investigations support and explain the anti-photocarcinogenic activity, in particular anti-non-melanoma skin cancer, of green tea and explain the benefits of green tea for human health.

Vitamin D in atopic dermatitis, asthma and allergic diseases

This review examines the scientific evidence behind the hypothesis that vitamin D plays a role in the pathogenesis of allergic diseases, along with a focus on emerging data regarding vitamin D and atopic dermatitis. Elucidated molecular interactions of vitamin D with components of the immune system and clinical data regarding vitamin D deficiency and atopic diseases are discussed. The rationale behind the sunshine hypothesis, laboratory evidence supporting links between vitamin D deficiency and allergic diseases, the clinical evidence for and against vitamin D playing a role in allergic diseases, and the emerging evidence regarding the potential use of vitamin D to augment the innate immune response in atopic dermatitis are reviewed.

Sun behaviour in Canadian children: results of the 2006 National Sun Survey

Childhood sun exposure is a particularly important determinant of skin cancer, yet little data are available for children. This paper describes sun behaviour among Canadian children for the summer of 2006. As part of the Second National Sun Survey (NSS2), 1,437 parents reported on the time spent in the sun, and the frequency of sun protection behaviours and sunburning for one of their children aged 1 to 12 years. Analysis was carried out using complex survey procedures in SAS and STATA. The majority of children (94%) spend at least 30 minutes in the sun on a typical summer day; however, regular sun protection is only commonly reported for young children (1 to 5 years) and involves covering their heads and wearing sunscreen (85%). The frequency of other protective behaviours is much lower, and sun protection decreases with age. Older children are also twice as likely to spend extended time in the sun and to get a sunburn. Among older children, boys are more likely to cover their heads and girls are more likely to wear sunscreen. Regular sun protection among Canadian children is low, given their sun exposure. Heavy reliance on sunscreen is consistent with previous reports and indicates that other measures, such as seeking shade and wearing protective clothing, need to be promoted. Riskier sun behaviour among older children may reflect decreased parental control, as well as changing attitudes and peer pressure, and highlights the importance of adult role models and targeted interventions for this age group.

Molecular mechanisms of inhibition of photocarcinogenesis by silymarin, a phytochemical from milk thistle (Silybum marianum L. Gaertn.) (Review)

Changes in life style over the past several decades including much of the time spent outdoors and the use of tanning devices for cosmetic purposes by individuals have led to an increase in the incidence of solar ultraviolet (UV) radiation-induced skin diseases including the risk of skin cancers. Solar UV radiations are considered as the most prevalent environmental carcinogens, and chronic exposure of the skin to UV leads to squamous and basal cell carcinoma and melanoma in human population. A wide variety of phytochemicals have been reported to have substantial anti-carcinogenic activity because of their antioxidant and anti-inflammatory properties. Silymarin is one of them and extensively studied for its skin photoprotective capabilities. Silymarin, a flavanolignan, is extracted from the fruits and seeds of milk thistle (Silybum marianum L. Gaertn.), and has been shown to have chemopreventive effects against photocarcinogenesis in mouse tumor models. Topical treatment of silymarin inhibited photocarcinogenesis in mice in terms of tumor incidence, tumor multiplicity and growth of the tumors. Wide range of in vivo mechanistic studies conducted in a variety of mouse models indicated that silymarin has anti-oxidant, anti-inflammatory and immunomodulatory properties which led to the prevention of photocarcinogenesis in mice. This review summarizes and updates the photoprotective potential of silymarin with the particular emphasis on its in vivo mechanism of actions. It is suggested that silymarin may favorably supplement sunscreen protection, and may be useful for skin diseases associated with solar UV radiation-induced inflammation, oxidative stress and immunomodulatory effects.

Economic evaluation of the US Environmental Protection Agency's SunWise program: sun protection education for young children

OBJECTIVE

The SunWise School Program is a school-based sun safety education program that was developed by the US Environmental Protection Agency and aims to teach children how to protect themselves from overexposure to the sun. The objectives of this study were to assess the health benefits of the SunWise School Program and use economic analysis to determine the program's net benefits and cost-effectiveness.

METHODS

Standard cost/benefit and cost-effectiveness analysis methods were used. Intervention costs were measured as program costs estimated to be incurred by the US government, which funds SunWise, using 3 funding scenarios. Health outcomes were measured as skin cancer cases and premature mortalities averted and quality-adjusted life-years saved. These health outcomes were modeled using an effectiveness evaluation of SunWise based on pretest and posttest surveys administered to students who participated in the program and the Environmental Protection Agency's peer-reviewed Atmospheric and Health Effects Framework model. Costs averted were measured as direct medical costs and costs of productivity losses averted as a result of SunWise. Net benefits were measured as the difference between costs averted and program costs.

RESULTS

Economic analysis indicated that if the SunWise School Program continues through 2015 at current funding levels, then it should avert >50 premature deaths, nearly 11,000 skin cancer cases, and 960 quality-adjusted life-years (undiscounted) among its participants. For every dollar invested in SunWise, between approximately $2 and $4 in medical care costs and productivity losses are saved, depending on the funding scenario.

CONCLUSIONS

From a cost/benefit and cost-effectiveness perspective, it is worthwhile to educate children about sun safety; small to modest behavioral impacts may result in significant reductions in skin cancer incidence and mortality.

Solar UVR Exposure, Concurrent Activities and Sun-Protective Practices Among Primary Schoolchildren

Comprehensive measures of ultraviolet radiation (UVR) exposure, concurrent activities and sun-protective practices are needed to develop and evaluate skin cancer prevention and sun protection interventions. The UVR exposures of 345 primary schoolchildren at 23 schools around New Zealand were measured using electronic UVR monitors for 1-week periods over 12 weeks in 2004 and 2005. In addition, ambient UVR levels on a horizontal surface were measured on-site at each school. Children completed activity diaries during the period UVR measurements were made and provided information on their indoor and outdoor status and clothing and sun protection worn. Mean total daily UVR exposure (7:00-20:00 h NZST + 1) at the body location where the UVR monitors were worn was 0.9 SED (standard erythemal dose, 1 SED = 100 J m(-2)). This was 4.9% of the ambient UVR on a horizontal surface. Mean time spent outdoors was 2.3 h day(-1). Differences in children's UVR exposure could be explained in part by activity, where outdoor passive pursuits were associated with higher UVR exposure rates than outdoor active and outdoor travel pursuits. Compared with older children, the activities of younger children, although labeled the same, resulted in different UVR exposures, either as a result of reporting differences or a real difference in UVR exposure patterns. UVR exposure rates were generally higher on weekdays compared with the weekend, confirming the important role of school sun protection and skin cancer prevention programs. High UVR exposure activities included physical education, athletics and lunch break.

Beneficial long-term effects of combined oral/topical antioxidant treatment with the carotenoids lutein and zeaxanthin on human skin: a double-blind, placebo-controlled study

BACKGROUND

The skin is exposed to numerous environmental assaults that can lead to premature aging. Of these agents, perhaps none is more ubiquitous than the ultraviolet (UV) wavelengths of sunlight. The primary immediate defense against environmental skin damage is the antioxidant capacity of the skin. However, this defense system can be compromised by moderate exposure to UV light. Therefore, bolstering the antioxidant defense system of the skin is a potentially important strategy for reducing environmentally induced skin damage.

AIM OF THE STUDY

This clinical trial was designed to study the efficacy of lutein and zeaxanthin, two potentially important antioxidants found naturally in the skin, upon five skin physiology parameters (surface lipids, hydration, photoprotective activity, skin elasticity and skin lipid peroxidation - malondialdehyde) of human subjects. These xanthophyllic carotenoids were administered either orally, topically, or in combination (both oral and topical routes).

RESULTS

The results obtained indicate that the combined oral and topical administration of lutein and zeaxanthin provides the highest degree of antioxidant protection. However, oral and topical administration of these antioxidants individually also provides significant activity in the skin. In addition, oral administration of lutein may provide better protection than that afforded by topical application of this antioxidant when measured by changes in lipid peroxidation and photoprotective activity in the skin following UV light irradiation.

Individual solar-UV doses of pupils and undergraduates in China

The solar-UV exposures of school pupils and medical undergraduates were studied over four seasons in Shenyang (latitude 41 degrees 11'-43 degrees 2', longitude 122 degrees 25'-123 degrees 48'), Liaoning, PR China. Ultraviolet exposure was measured using personal ultraviolet radiation (UVR) sensor on sunny days along with simultaneous monitoring and recording of direct-ambient UVR dose (perpendicular UV dose) for comparison. We observed that the UV doses of pupils on weekdays were higher than those on weekends and that the UV doses of the pupils were significantly higher than those of the undergraduates during both weekdays and weekends. The percent of the mean individual daily UV dose to the environmental counterpart are 2.88% (Autumn), 7.76% (Winter), 3.77% (Spring) and 2.06% (Summer) for the pupils, and corresponding percent for the undergraduates are 0.88%, 0.32%, 0.67% and 0.81%. The means of minimum erythemal dose values with pupils for weekday (5 days), weekend (2 days) and week (7 days) through the whole year are 0.302 (0.275 ~ 0.328), 0.215 (0.170 ~ 0.261) and 0.278 (0.255 ~ 0.301), respectively. The corresponding means with undergraduates are 0.097 (0.081~ 0.113), 0.091 (0.070 ~ 0.112) and 0.095 (0.082 ~ 0.108), respectively. Although the season is a major factor influencing the personal direct-ambient percent, it is emphasized that the impact of the lifestyle cannot be ignored.

Youth solar ultraviolet radiation exposure, concurrent activities and sun-protective practices: a review

To assist standardization of procedures, facilitate comparisons, and help guide research efforts to optimally inform development of appropriately targeted interventions, there is a need to review methods used to quantify child and adolescent solar ultraviolet radiation (UV) exposure, related outdoor activities and sun-protective practices. This holistic approach is essential for comprehensive research that will provide all-inclusive, informative and meaningful messages for preventive measures of harmful UV exposure. Two databases were searched and 29 studies were retrieved, and these studies report measurement or assessment techniques documenting UV exposure patterns and related outdoor activities. Polysulfone film badges were the main measurement instrument used in 10 studies, with questionnaire, survey data, observation, a model, electronic dosimeters, biological dosimeters, colorimeter and UV colouring labels used in the remaining studies. Methods used to record activities included self-report, parental report, a logbook and observation. Measurement duration and unit of UV exposure varied in most studies, but a method common to 15 studies was measured UV exposure as a percentage of ambient UV. The studies reviewed do not provide sufficient information for the development and evaluation of targeted youth sun protection programs. Studies are required which document precise UV exposure, concurrent activities and sun protection usage for children and adolescents.

Long-term ingestion of high flavanol cocoa provides photoprotection against UV-induced erythema and improves skin condition in women

Dietary antioxidants contribute to endogenous photoprotection and are important for the maintenance of skin health. In the present study, 2 groups of women consumed either a high flavanol (326 mg/d) or low flavanol (27 mg/d) cocoa powder dissolved in 100 mL water for 12 wk. Epicatechin (61 mg/d) and catechin (20 mg/d) were the major flavanol monomers in the high flavanol drink, whereas the low flavanol drink contained 6.6 mg epicatechin and 1.6 mg catechin as the daily dose. Photoprotection and indicators of skin condition were assayed before and during the intervention. Following exposure of selected skin areas to 1.25 x minimal erythemal dose (MED) of radiation from a solar simulator, UV-induced erythema was significantly decreased in the high flavanol group, by 15 and 25%, after 6 and 12 wk of treatment, respectively, whereas no change occurred in the low flavanol group. The ingestion of high flavanol cocoa led to increases in blood flow of cutaneous and subcutaneous tissues, and to increases in skin density and skin hydration. Skin thickness was elevated from 1.11 +/- 0.11 mm at wk 0 to 1.24 +/- 0.13 mm at wk 12; transepidermal water loss was diminished from 8.7 +/- 3.7 to 6.3 +/- 2.2 g/(h x m2) within the same time frame. Neither of these variables was affected in the low flavanol cocoa group. Evaluation of the skin surface showed a significant decrease of skin roughness and scaling in the high flavanol cocoa group compared with those at wk 12. Dietary flavanols from cocoa contribute to endogenous photoprotection, improve dermal blood circulation, and affect cosmetically relevant skin surface and hydration variables.

Sun exposure and risk of melanoma

BACKGROUND

As skin cancer education programmes directed to children and adolescents continue to expand, an epidemiological basis for these programmes is necessary to target efforts and plan for further evaluation.

AIMS

To summarise the epidemiological evidence on sun exposure during childhood and adolescence and melanoma risk.

METHODS

A literature review was conducted using Medline (1966 to December 2004) to identify articles relating to sun exposure and melanoma. The review was restricted to studies that included sun exposure information on subjects 18 years of age or younger.

RESULTS

Migrant studies generally indicate an increased melanoma risk in individuals who spent childhood in sunny geographical locations, and decreasing melanoma risk with older age at arrival. Individuals who resided in geographical locations close to the equator or close to the coast during childhood and/or adolescence have an increased melanoma risk compared to those who lived at higher latitudes or never lived near the coast. The intermittent exposure hypothesis remains controversial; some studies indicate that children and adolescents who received intermittent sun exposure during vacation, recreation, or occupation are at increased melanoma risk as adults, but more recent studies suggest intermittent exposure to have a protective effect. The majority of sunburn studies suggest a positive association between early age sunburn and subsequent risk of melanoma.

CONCLUSION

Future research efforts should focus on: (1) clarifying the relation between sun exposure and melanoma; (2) conducting prospective studies; (3) assessing sun exposure during different time periods of life using a reliable and quantitative method; (4) obtaining information on protective measures; and (5) examining the interrelations between ability to tan, propensity to burn, skin type, history of sunburns, timing and pattern of sun exposure, number of nevi, and other host factors in the child and adolescent populations.

Chemoprevention of photocarcinogenesis by selected dietary botanicals

Epidemiological, clinical and laboratory studies have implicated solar ultraviolet (UV) radiation as a tumor initiator, tumor promoter and complete carcinogen, and their excessive exposure can lead to the development of various skin disorders including melanoma and nonmelanoma skin cancers. Sunscreens are useful, but their protection is not adequate to prevent the risk of UV-induced skin cancer. It may be because of inadequate use, incomplete spectral protection and toxicity. Therefore new chemopreventive methods are necessary to protect the skin from photodamaging effects of solar UV radiation. Chemoprevention refers to the use of agents that can inhibit, reverse or retard the process of skin carcinogenesis. In recent years, considerable interest has been focused on identifying naturally occurring botanicals, specifically dietary, for the prevention of photocarcinogenesis. A wide variety of botanicals, mostly dietary flavonoids or phenolic substances, have been reported to possess substantial anticarcinogenic and antimutagenic activities because of their antioxidant and antiinflammatory properties. This review summarizes chemopreventive effects of some selected botanicals, such as apigenin, curcumin, grape seed proanthocyanidins, resveratrol, silymarin, and green tea polyphenols, against photocarcinogenesis in in vitro and in vivo systems. Attention has also been focused on highlighting the mechanism of chemopreventive action of these dietary botanicals. We suggest that in addition to the use of these botanicals as dietary supplements for the protection of photocarcinogenesis, these botanicals may favorably supplement sunscreens protection and may provide additional antiphotocarcinogenic protection including the protection against other skin disorders caused by solar UV radiation.

Ultraviolet radiation exposure pattern in winter compared with summer based on time-stamped personal dosimeter readings

BACKGROUND

Personal annual ultraviolet (UV) radiation data based on daily records are needed to develop protective strategies.

OBJECTIVES

To compare UV radiation exposure patterns in the winter half-year (October-March) and the summer half-year (April-September) for Danish indoor workers.

METHODS

Nineteen indoor workers (age range 17-56 years) wore personal UV dosimeters, measuring time-stamped UV doses continuously during a year. The corresponding sun exposure behaviour was recorded in diaries. Similar data were collected for 28 volunteers during sun holidays in the winter half-year. The relationship between UV dose and sun exposure behaviour was analysed.

RESULTS

The ambient UV dose during the winter in Denmark (at 56 degrees N) was 394 standard erythema doses (SED) or 10.5% of the annual ambient UV dose. In winter compared with summer the subjects had: (i) a lower percentage of ambient UV radiation, 0.82% vs. 3.4%; (ii) a lower solar UV dose in Denmark, 3.1 SED (range 0.2-52) vs. 133 SED (range 69-363); (iii) less time outdoors per day with positive dosimeter measurements, 10 min vs. 2 h; and (iv) no exposure (0 SED) per day on 77% vs. 19% of the days. Sun holidays outside Denmark in winter gave a median 4.3 SED per day (range 0.6-7.6) and 26 SED (range 3-71) per trip.

CONCLUSIONS

In the winter half-year indoor workers received a negligible UV dose from solar exposure in Denmark and needed no UV precautions. No UV precautions are needed from November to February during holidays to latitudes above 45 degrees N, while precautions are needed the whole year around at lower latitudes.

Proportion of lifetime UV dose received by children, teenagers and adults based on time-stamped personal dosimetry

Ultraviolet (UV) reduction campaigns since 1986 were based on the estimation that individuals get 80% of their cumulative lifetime UV dose by the age of 18. To investigate if this estimation is true, we compared annual UV doses received during life in 164 Danish volunteers: children, teenagers, indoor workers, and golfers (age range 4-67 y) who recorded sun exposure behavior in diaries and carried personal UV dosimeters, measuring time-stamped UV doses. The annual UV dose did not significantly correlate with age but the variation in annual UV dose was high (median 166 SED (standard erythema dose), 95% range: 37-551 SED). The annual UV dose did correlate with days with risk behavior (sunbathing/exposing upper body) (r=0.51, p<0.001) and in adults also with hours performing outdoor sports (r=0.39, p<0.001), gardening, and sun-bed sessions (r=0.26, p=0.02). Teenagers had significantly more days with risk behavior than adults (21 vs 13 d, p=0.006) but not than children (15 d). No differences in UV dose among the age groups were found on workdays. Only 25% of the lifetime UV dose was received before the age of 20 and the annual UV dose was thus independent of age. Reduction of cumulative lifetime UV dose could be obtained by minimizing risk behavior.

UV Doses Worldwide†

UV radiation affects human health. Human exposure to UV radiation causes a few beneficial health effects like vitamin D3 formation but it causes many detrimental health effects: sunburn, ocular damage, photoaging, immune suppression, DNA damage and skin cancer. In countries with fair-skinned populations, skin cancer is the most diagnosed of all cancers. In the United States in 2002, there were over one million new skin cancer cases. That means one out of every 285 people got skin cancer. Skin cancer of fair-skinned individuals is increasing at an alarming rate (4-6% per year) around the world and has now reached so-called "pandemic" proportions. Thus, it is important to know what UV doses people around the world get throughout their lives. This review covers how the outdoor UV doses are weighted for different biological effects, the most commonly used measuring devices for terrestrial and personal UV doses, the natural and other effects on terrestrial and personal UV doses, the time people spend outside, their ambient exposures and the terrestrial and personal UV doses of adult outdoor and indoor workers as well as children and adolescents around the world. Overall, outdoor-working adults get about 10%, while indoor-working adults and children get about 3% (2-4%) of the total available annual UV (on a horizontal plane). People's UV doses increase with increasing altitude and decreasing latitude; most indoor-working adult Europeans get 10,000-20,000 J/m2 per year, Americans get 20,000-30,000 J/m2 per year and Australians are estimated to get 20,000-50,000 J/m2 per year (excluding vacation, which can increase the dose by 30% or more).

Nutritional protection against skin damage from sunlight

The concept of systemic photoprotection by dietary means is gaining momentum. Skin is continuously exposed to ultraviolet (UV) radiation, the major cause of skin disorders such as sunburn, photodamage, and nonmelanoma skin cancer. Most of the erythemal annual UV dose is encountered under nonvacation conditions, when no sunscreen is applied. In the absence of topically added compounds, skin protection depends solely on endogenous defense. Micronutrients can act as UV absorbers, as antioxidants, or can modulate signaling pathways elicited upon UV exposure. UV-induced erythema is a suitable parameter to assess photoprotection. Dietary protection is provided by carotenoids, tocopherols, ascorbate, flavonoids, or n-3 fatty acids, contributing to maintenance resistance as part of lifelong protection.

UV doses of young adults

Since 1986, people have been informed that they get about 80% of their lifetime ultraviolet (UV) dose by the age of 18. This belief originated from the mathematical conclusion that diligent use of sunscreens (sun protection factor 15 or higher) during the first 18 years of life would reduce the lifetime incidence of nonmelanoma skin cancers by 78%. These data were misconstrued to mean that individuals also got about 80% of their lifetime dose of UV by the age of 18 (linear relationship). However, these calculations were based on the incidence of nonmelanoma skin cancers being related to the square of the UV dose. Careful analysis of UV exposure data shows that Americans actually get less than 25% of their lifetime UV dose by the age of 18. This finding also appears to be true worldwide because Australia, UK and The Netherlands report a similar UV exposure pattern. UV-initiated damage early in life can be promoted by subsequent exposures to progress into tumors later in life. For example, the nonmelanoma skin cancer, squamous cell carcinoma, is dependent on the cumulative UV dose. Thus, a better educational approach for reducing skin cancers would be to instruct fair-skinned individuals to protect themselves throughout their lives from being exposed to too much UV radiation.