Peter Gies

Higher 25-hydroxyvitamin D Is Associated with Lower Relapse Risk in Multiple Sclerosis

A protective association between higher vitamin D levels and the onset of multiple sclerosis (MS) has been demonstrated; however, its role in modulating MS clinical course has been little studied. We investigated whether higher levels of serum 25‐hydroxyvitamin D (25‐OH‐D) were associated with a lower risk of relapses in people with MS.

Solar and ultraviolet radiation

Solar UVR is the most important source of ultraviolet radiation (UVR) to which the world’s population is exposed. The long-term effects of these UVR exposures are dealt with in later chapters but a brief description of the biological effects of UVR is given here and an overview of the measurement of UVR is also provided. The chapter provides a detailed exploration of the range of factors that affect solar UVR at the earth’s surface and includes a summary of solar UVR levels around the world. The role of personal behavior when outdoors, perhaps the most important factor determining an individual’s exposure to solar UVR, is then examined as being the main potential avenue to modify and reduce these exposures. The chapter concludes with an overview of artificial sources of UVR and their associated hazards.

PERSONAL DOSIMETRY OF SOLAR UV RADIATION FOR DIFFERENT OUTDOOR ACTIVITIES

Abstract Quantifying individual exposure to ultraviolet radiation (UVR) is critical to understanding the etiology of a number of diseases including nonmelanotic and melanotic skin cancers. Measurements of personal exposure to solar UVR were made in Hobart, Tasmania in February (summer) 1991 for six different outdoor activities using UVR‐sensitive polysulfone (PS) film attached at seven anatomical sites. Concurrent behavioral and environmental observations were also made. To date many studies have relied on subject recall to quantify past solar UVR exposures. To gain insight into the accuracy of subject recall the measured UVR exposures received by different subjects using the PS film were compared to those calculated from personal diaries and ambient solar UVB levels from a monitoring station. In general, when UVR exposure activities took place under close supervision, good correlations were obtained between the PS badges and the ambient measurements/diaries approach. Ultraviolet radiation exposures for the field study involving 94 subjects engaged in a number of outdoor activities are presented.

Measured Solar Ultraviolet Radiation Exposures of Outdoor Workers in Queensland in the Building and Construction Industry

The risk to outdoor workers of exposure to solar ultraviolet radiation (UVR) has been known for some time, particularly in the building and construction industry, where workers often use little in the way of protection against solar UVR. In recent years there have been attempts by authorities in Australia and in Queensland in particular, where UVR levels in spring and summer are very high to extreme, to instigate and to encourage the use of personal UVR protection by outdoor workers. To quantify UVR exposure of building and construction industry workers involved in typical outdoor work, a study was conducted using UVR‐sensitive polysulphone film badges. The results indicated that the doses were significant, often well in excess of recommended exposure limits. The measured exposures varied between trades. Data on the use of personal UVR‐protective equipment and the skin type of workers were also collected. Many of the workers had skin types that were sensitive to UVR and showed signs of sunburn. In summary, the study found that at‐risk individuals were exposed to extreme levels of UVR, in most cases without adequate and appropriate sun protection.

Global Solar UV Index: Australian measurements, forecasts and comparison with the UK.

Abstract The 2002 revision of the UV index (UVI) issued by the World Health Organisation (WHO), the World Meteorological Office (WMO), the United Nations Environment Programme (UNEP) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP) (World Health Organization [2002] Global Solar UV Index: A Practical Guide. WHO, Geneva) was motivated by the need to further standardize the use and presentation of the UVI. Awareness of the hazards of solar UV radiation (UVR) is generally high in Australia, but more effective use of the UVI will assist in promoting further changes to the populations sun exposure behavior. UVI levels for a number of cities around Australia as measured by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), covering the time period 1996–2000, are presented. Also shown are UVI forecasts from the Australian Bureau of Meteorology (BOM). Agreement between the BOM data and the measurements varies depending on the location but is within 2 UVI units approximately 75% of the time. UVI levels are supplied to the media, and in summer values in excess of 12–14 are regularly recorded, although the more northerly locations occasionally reach 16 and 17. The factors affecting the solar UVR environment and the measured UVI are also discussed and compared against measurements from the UK.

Solar UVR Exposures of Primary School Children at Three Locations in Queensland

Abstract— The ultraviolet radiation (UVR) exposures of primary school children in Brisbane, Toowoomba and Mackay (latitudes 27°30′, 27°33′ and 21°15′ south, respectively) were assessed over a period of 2 weeks at each location using UVR‐sensitive polysulfone (PS) film badges attached at the shoulder. The students filled in questionnaires on their time spent outdoors for each day of the study. These data in conjunction with the ambient UVR measured by a detector/datalogger unit at each site were used to correlate the calculated exposures with those measured using the PS badges. Overall, the questionnaires indicated that the males spent more time outdoors and had higher measured UVR exposures than females. For both boys and girls at each location, there was a strong correlation between the mean measured UVR exposure and the ambient solar UVR at that location.

Surface UV radiation over Australia, 1979–1992: Effects of ozone and cloud cover changes on variations of UV radiation

Time series of daily erythemal ultraviolet radiation (UVR) exposure, ozone, and cloud cover were analyzed over the Australian continent using data sets from the NASA Total Ozone Mapping Spectrometer (TOMS) from 1979–1992. The TOMS UVR exposures showed good agreement with data from surface observations. Using a relationship derived from comparisons of the TOMS partial cloud reflectivities with surface cloud cover observations, the TOMS reflectivities were converted into estimates of cloud cover for several Australian regions. It was shown that the deseasonalized time series of UVR exposures can be statistically described as a linear function of ozone and cloud cover anomalies. Results of a trend analysis indicated statistically significant increases in UVR exposures of 10% decade−1 in the summer months in the tropics. These were associated with a simultaneous depletion of ozone and a decrease in cloud cover. Midlatitudinal regions showed no significant trends of UVR. It was found that variations of ozone and UVR over Australia were significantly influenced by the quasi-biennial oscillation (QBO). An increase in zonal wind strength of 20 m s−1 was correlative with reductions of ozone of 1.7% and enhancements of UVR exposures of 2.2%. An increase in solar radio flux of 100×10−22 W m−2 (Hz)−1 was associated with significant reductions of UVR of 5–10% in the tropical and subtropical regions in summer. The results suggested that enhancements in summer UVR exposures of about 10–20% above the climatological average might be expected in years in which the QBO is in its westerly phase and the solar cycle is at its minimum.

Validity of Self-Reported Sunscreen Use by Parents, Children, and Lifeguards

BACKGROUND Verbal self-report is the method most often used to assess sunscreen use, but the data may be confounded by recall error and social desirability. Sunscreen swabbing is a non-invasive procedure to objectively assess the presence of sunscreen on the skin. This study examined the agreement between verbal reports of sunscreen use from survey and diary measures and objectively measured sunscreen use. METHODS Participants were 564 parents, children aged 5-10 years, and lifeguards at 16 swimming pools in four regions of the U.S. Participants completed self-reported measures, including baseline and final surveys, as well as a 4-day diary and objective swabbing measures of sunscreen presence on 2 separate days. Data were collected in 2006 and analyzed in 2006-2007. RESULTS Levels of sunscreen use were relatively high based on surveys (65.7%); diary data (40.3%); and swabbing measures (59.1%). Agreement between swabbing and diary measures of sunscreen use was fair to good, with kappa statistics for children at 0.40, followed by lifeguards at 0.34 and parents at 0.27. Validity coefficients across measures of sunscreen use were higher for lifeguards and parents than for children, and diary measures were higher than surveys. No systematic errors were found across groups or by gender, latitude, study arm, or risk category. CONCLUSIONS These findings are comparable to those in other validation studies, including studies of the validity of dietary assessments. Self-reported estimates of sunscreen use by diaries or surveys appear to be as good as objective measures.

Photoprotection by clothing

The increasing use and importance of clothing for sun protection for children is now a key element in a range of protection strategies, where reducing ultraviolet radiation (UVR) exposures in early life is fundamental to skin cancer prevention programmes. Other applications of photoprotection by clothing are sun protection of outdoor workers in occupational situations, sun protection of the general population in recreational situations, protection of photosensitive patients and protection of workers exposed to intense artificial sources of UVR such as welding. The broadest application and the one that this article will mainly concentrate on is clothing and sun protection, although there will be some discussion on the other areas. Before 1990, there were very few references in the scientific literature on clothing and UVR protection (1–10) and many of these were to do with clothing and transmission of UVR from artificial sources. However, this situation has changed dramatically over the last 10 years, where there has been a surge of interest, with numerous publications dealing with the factors that affect the UVR protection provided by fabrics and garments. This in turn has lead to the rating of the sun protection provided by clothing, the development of lightweight, comfortable clothing that is highly UVR protective as well as other advances such as wash and wear treatments to increase the UVR protection of existing clothing. A comprehensive and detailed summary of much of the work on clothing and UVR is in the recently released report of the Commission Internationale de l’Eclairage (CIE) or International Commission on Illumination Technical Committee 6–29 entitled ‘UV Protection and Clothing’ CIE 172:2006 (11).

Validity of Self-reported Solar UVR Exposure Compared with Objectively Measured UVR Exposure

Background: Reliance on verbal self-report of solar exposure in skin cancer prevention and epidemiologic studies may be problematic if self-report data are not valid due to systematic errors in recall, social desirability bias, or other reasons. Methods: This study examines the validity of self-reports of exposure to ultraviolet radiation (UVR) compared to objectively measured exposure among children and adults in outdoor recreation settings in 4 regions of the United States. Objective UVR exposures of 515 participants were measured using polysulfone film badge UVR dosimeters on 2 days. The same subjects provided self-reported UVR exposure data on surveys and 4-day sun exposure diaries, for comparison to their objectively measured exposure. Results: Dosimeter data showed that lifeguards had the greatest UVR exposure (24.5% of weekday ambient UVR), children the next highest exposures (10.3% ambient weekday UVR), and parents had the lowest (6.6% ambient weekday UVR). Similar patterns were observed in self-report data. Correlations between diary reports and dosimeter findings were fair to good and were highest for lifeguards (r = 0.38–0.57), followed by parents (r = 0.28–0.29) and children (r = 0.18–0.34). Correlations between survey and diary measures were moderate to good for lifeguards (r = 0.20–0.54) and children (r = 0.35–0.53). Conclusions: This is the largest study of its kind to date, and supports the utility of self-report measures of solar UVR exposure. Impact: Overall, self-reports of sun exposure produce valid measures of UVR exposure among parents, children, and lifeguards who work outdoors. Cancer Epidemiol Biomarkers Prev; 19(12); 3005–12. ©2010 AACR.