Sun protection offered by fabrics: on the relation between effective doses based on different action spectra

Sun-protective Properties of Technical Sportswear Fabrics 100% Polyester: The Influence of Moisture and Sweat on Protection against Different Biological Effects of Ultraviolet (UV) Radiation

The use of technical sportswear is now widespread, but the degree of protection these fabrics offer against UV radiation is not known. We have analyzed the capacity of different types of technical sportswear fabrics to protect against different UV biological effects. A sample of 34 100% polyester t-shirts from different manufactures was classified by color, fabric structure, cover factor, and due to different tonalities, dark, and clear color. Ultraviolet protection factor was calculated according to UNE-EN13758. The protection factor for other biological effects as pre-vitamin D₃ production, non-melanoma skin cancer, photoimmunosuppression, and photoaging was analyzed. The effects of moisture and sweat in protection were also evaluated. From the analyzed sample garments, more than 75% achieved an excellent protection value (protection factor 40-50+). Higher values were found in double-layer type (P < 0.05). Cover factor was the main determinant of biological protection factors with correlation coefficients of 0.81 for UPF (erythema), 0.77 for NMSC, and 0.63 for photoimmunosuppression. Water or sweat humidity saturation increased biological protection factors over a 20% (P < 0.05). The 83% of the fabrics analyzed showed less than 5% of transmittance with labeling as UVA protective elements. No effect of fabric color was found related to biological protection factors. The 100% polyester sports T-shirts of the analyzed sample offer general protection against UV for different biological effects that can be increased by humidity but no affected by fabric color.

Mechanisms and treatments of photoaging

Photoaging is frequently encountered in a dermatologic practice. This systematic literature review aims to explore the etiology of photoaging and address the evidence behind its current management. A comprehensive search of MEDLINE, EMBASE, UpToDate, and the Cochrane Library was conducted. Articles were limited to those relating to photoaging. There are two major approaches in the current management of photoaging. This includes strategies to prevent against ultraviolet damage (e.g. sunscreen) and medications that attempt to reverse existing skin damage (topical retinoids and 5-fluorouracil). There has been a large growth in the variety of treatment options in recent years. While it is important for such growth to continue, prevention via sensible photoprotection methods still remains the best current management option.

New advances in protection against solar ultraviolet radiation in textiles for summer clothing

Clothing is considered one of the most important tools for photoprotection against harmful solar ultraviolet radiation (UVR). The standard for sun-protective clothing is based on erythema despite other biological effects of UVR on the skin. We analyzed the potential protection against UVR in fabrics destined for summer clothing based on several action spectra. We examined 50 garments classified by type of fabric composition, structure of the fiber yarn and color. The ultraviolet protection factor was calculated based on fabric ultraviolet transmittance corrected for erythema according to the EU standard E-13758 as well as the UVA transmittance of fabrics. UVR protection was also analyzed in base of different action spectra as for previtamin D3, nonmelanoma skin cancer, photoimmunosuppression and photoaging. Most knitted fabrics used for sports T-shirts offered excellent ratings for ultraviolet protection while normal shirts showed very low ratings, particularly against photoaging. The cover is the most influential variable in fabric photoprotection, having an exponential relationship with the UPF. The relation between cover and UVA protection was linearly negative. Information about ultraviolet protection in textiles used for summer clothing should be included in labeling as some types of fabrics, especially those used for shirts, offer very low UVR protection.

Professional risk for skin cancer development in male mountain guides--a cross-sectional study

OBJECTIVE

For reasons of their outdoor work, mountain guides (MG) are heavily exposed to ultraviolet radiation during their work.

METHODS

A standardized interview and examination were performed on 283 male MG (median 41 years) from Germany, Switzerland and Austria and 309 age-matched controls. The median occupation time as MG was 17 years; 39.9% were working full-time.

RESULTS

The incidence of skin cancer and precancerous lesions was obtained. Precancerous lesions as solar keratosis (SK) were significantly more frequent in MG (25.4% vs. 7.4%). There was no skin cancer [BCC, SSC, melanoma (MEL)] in the control subjects. Basal cell carcinoma (BCC) was diagnosed in 20 MG (7.1%) and SSC in four MG (1.4%). There were 10 highly suspicious melanocytic lesions; one MG had a histologically confirmed malignant MEL. Risk factors for SK in the multivariate analysis included occupation (P < 0.0001), age (P < 0.0001) and skin type (P = 0.0002). Within the MG group, age (P < 0.0001) and hair colour (P = 0.0058) were independent risk factors for SK. Severe lifetime sunburns (P = 0.0007) and skin type (P = 0.041) were the significant risk factors for BCC, within the MG group in addition to the number of guiding days (P = 0.010). The risk factor for skin cancer (BCC, SCC and MEL) was the number of heavy sunburns during lifetime (P = 0.0014).

CONCLUSION

The present study demonstrates an association between high occupational ultraviolet-exposure and an increased prevalence of precancerous skin lesions and skin cancer. MG may be considered as an example for other outdoor professionals. Skin cancer of outdoor workers is likely to be an occupational disease. Primary and secondary prevention should be enforced.

Photoprotection

Sun exposure is the main cause of photocarcinogenesis, photoageing, and photosensitivity; thus, photoprotection is an important issue. In a skin cancer prevention strategy, behavioural measures--eg, wearing sun protective clothes and a hat and reducing sun exposure to a minimum--should be preferred to sunscreens. Often this solution is deemed to be unacceptable in our global, outdoor society, and sunscreens could become the predominant mode of sun protection for various societal reasons (eg, healthiness of a tan, relaxation in the sun). The application of a liberal quantity of sunscreen has been shown to be by far the most important factor for effectiveness of the sunscreen, followed by the uniformity of application and the specific absorption spectrum of the agent used. The sunscreen market--crowded by numerous products--shows various differences worldwide. Nevertheless, sunscreens should not be abused in an attempt to increase time in the sun to a maximum. Controversies about safety of sunscreens and clinical recommendations are discussed.

Hypothesis: hair cover can protect against invasive melanoma on the head and neck (Australia)

The anatomic distribution of cutaneous melanoma reflects people's levels and patterns of sun exposure. While examining trends of incident invasive melanomas by site in recent decades in Australia we noted significant increases in incidence on the ears but not the face or any other site in women younger than 40 years, by 6% (95% confidence interval [CI] 2-10%) per year, and 40-59 years by 7% (95% CI 4-10%) per year. Men of the same age showed no corresponding changes in ear melanoma. However incidence rates of ear melanoma in general were fourfold higher in males than females in Australia. Further, using data from the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) Program, rates of invasive melanoma on the ear were found to be sevenfold higher in males than females in the US population in the same period. Higher rates of scalp and neck melanomas were also seen in men and women in both populations. We therefore speculated that the isolated rises of ear melanoma in younger women in Australia, and the higher overall rates of ear, scalp and neck melanoma in men compared with women, reflect differences in hair coverage. We tested the specific hypothesis that hair cover reduces sun exposure of the ears using experimental manikins and found that hair cover of the ear reduced solar ultraviolet-B exposure by 81% [SE +/-8] compared with uncovered ears. We conclude that hair cover can protect against invasive melanoma on the ear and may similarly protect on the scalp and neck. When discretionary, hair may be an important additional factor to be considered for melanoma prevention.

The European standard for sun-protective clothing: EN 13758

Clothing is considered one of the most important tools for sun protection. Contrary to popular opinion, however, some summer fabrics provide insufficient ultraviolet (UV) protection. The European Committee for Standardization (CEN), has developed a new standard on requirements for test methods and labelling of sun-protective garments. This document has now been completed and is published. Within CEN, a working group, CEN/TC 248 WG14 'UV protective clothing', was set up with the mission to produce standards on the UV-protective properties of textile materials. This working group started its activities in 1998 and included 30 experts (dermatologists, physicists, textile technologists, fabric manufacturers and retailers of apparel textiles) from 11 European member states. Within this working group, all medical, ethical, technical and economical aspects of standardization of UV-protective clothing were discussed on the basis of the expertise of each member and in consideration of the relevant literature in this field. Decisions were made in consensus. The first part of the standard (EN 13758-1) deals with all details of test methods (e.g. spectrophotometric measurements) for textile materials and part 2 (EN 13758-2) covers classification and marking of apparel textiles. UV-protective cloths for which compliance with this standard is claimed must fulfill all stringent instructions of testing, classification and marking, including a UV protection factor (UPF) larger than 40 (UPF 40+), average UVA transmission lower than 5%, and design requirements as specified in part 2 of the standard. A pictogram, which is marked with the number of the standard EN 13758-2 and the UPF of 40+, shall be attached to the garment if it is in compliance with the standard. The dermatology community should take cognizance of this new standard document. Garment manufacturers and retailers may now follow these official guidelines for testing and labelling of UV-protective summer clothes, and the sun-aware consumer can easily recognize garments that definitely provide sufficient UV protection.

Photoprotection in teenagers

BACKGROUND

It is very common to apply a 'template photoprotection' without taking into consideration the background of a specific population. In Lebanon, so far, no preliminary survey has been conducted before launching an educational photoprotection campaign, revealing the need of the people according to their background.

MATERIALS AND METHODS

In April 2004, a specific questionnaire was administered to 940 adolescents, aged from 14 to 18 years. The questionnaire comprised 18 multiple-choice questions that established the approximate phototype of teenagers, awareness of ultraviolet (UV) hazard, presence of sufficient information regarding the risk of sun exposure (school, doctor, media) and the use of measures of photoprotection (clothes, sunscreens).

RESULTS

The incidence of sunburn in teenagers was high (85.42%) despite their awareness of the risks of unprotected sun exposure. The information regarding sun damage seems to be insufficiently delivered at school and by doctors. The main source of information was television. It was obvious that our adolescents underestimated the value of clothing to protect themselves. The use of clothing comes at the second place after sunscreens. However, the application of sunscreen seems to be inadequate.

CONCLUSIONS

While solar protection has become part of routine beach behavior for adolescents, there is room for improvement with better application of sunscreen and more use of clothing, especially wearing hats, and seeking shade. However, it is difficult to appreciate the impact of publicity campaigns on the risks of sun exposure in reducing the incidence of melanoma.

Protection from visible light by commonly used textiles is not predicted by ultraviolet protection

Interest is increasing in the prevention of acute and chronic actinic damage provided by clothing. This interest has focused mainly on protection against ultraviolet irradiation, but it has now also turned to protection against visible light. This change is mainly due to the action spectrum in the visible light range of some photodermatoses and the increasing interest in photodynamic therapy. The ultraviolet protection provided by commercially available textiles can be graded by determining an ultraviolet protection factor. Several methods have already been used to determine the ultraviolet protection factor. The fact that protection from visible light by textiles cannot be predicted by their ultraviolet protection makes the situation more complicated. This study attempts to determine whether or not the ultraviolet protection factor value of a particular textile is a good parameter for gauging its protection in the visible light range and concludes that a protection factor of textile materials against visible light needs to be developed. This development should go beyond the protection factor definition used in this article, which has some limitations, and should take into account the exact action spectrum for which the protection is needed.