The Relationship between Ultraviolet Radiation Exposure and Vitamin D Status

This paper reviews the main factors influencing the synthesis of vitamin D, with particular focus on ultraviolet radiation exposure. On the global level, the main source of vitamin D is the sun. The effect of solar radiation on vitamin D synthesis depends to some extent on the initial vitamin D levels. At moderate to high latitudes, diet becomes an increasingly important source of vitamin D due to decreased solar intensity and cold temperatures, which discourage skin exposure. During the mid-winter season, these factors result in decreased solar radiation exposure, hindering extensively the synthesis of vitamin D in these populations

The High Prevalence of Vitamin D Insufficiency across Australian Populations Is Only Partly Explained by Season and Latitude

Background Inadequate sun exposure and dietary vitamin D intake can result in vitamin D insufficiency. However, limited data are available on actual vitamin D status and predictors in healthy individuals in different regions and by season.Methods We compared vitamin D status [25-hydroxyvitamin D; 25(OH)D] in people &lt; 60 years of age using data from cross-sectional studies of three regions across Australia: southeast Queensland (27&deg;S; 167 females and 211 males), Geelong region (38&deg;S; 561 females), and Tasmania (43&deg;S; 432 females and 298 males).Results The prevalence of vitamin D insufficiency (&le; 50 nmol/L) in women in winter/spring was 40.5% in southeast Queensland, 37.4% in the Geelong region, and 67.3% in Tasmania. Season, simulated maximum daily duration of vitamin D synthesis, and vitamin D effective daily dose each explained around 14% of the variation in 25(OH)D. Although latitude explained only 3.9% of the variation, a decrease in average 25(OH)D of 1.0 (95% confidence interval, 0.7&ndash;1.3) nmol/L for every degree increase in latitude may be clinically relevant. In some months, we found a high insufficiency or even deficiency when sun exposure protection would be recommended on the basis of the simulated ultraviolet index.Conclusion Vitamin D insufficiency is common over a wide latitude range in Australia. Season appears to be more important than latitude, but both accounted for less than one-fifth of the variation in serum 25(OH)D levels, highlighting the importance of behavioral factors. Current sun exposure guidelines do not seem to fully prevent vitamin D insufficiency, and consideration should be given to their modification or to pursuing other means to achieve vitamin D adequacy.<br /

How Does the European Recovery Target for Construction &Demolition Waste Affect Resource Management?

The revised EU Waste Framework Directive (WFD) includes a 70 % target for recovery of construction and demolition (C&D) waste. In order to study the potential change in the resource management of the main C&D waste fractions, as a consequence of fulfilling the WFD target, a Nordic project (ENCORT-CDW) has been performed. Waste fractions studied included asphalt, concrete, bricks, track ballast, gypsum-based construction materials and wood. Recovery scenarios were identified and estimations were made regarding expected savings of primary materials, impact on transport, and pollution and emissions. For wood waste, the main differences between re-use, material recycling and energy recovery were evaluated in a carbon footprint screening based on life cycle assessment methodology. The study concluded that the EU recovery target does not ensure a resource efficient and environmentally sustainable waste recovery in its present form since: It is very sensitive to how the legal definitions of waste and recovery are interpreted in the Member States. This means that certain construction material cycles might not count in the implementation reports while other, less efficient and environmentally safe, recovery processes of the same material will count. • It is weight-based and consequently favours large and heavy waste streams. The result is that smaller flows with equal or larger resource efficiency and environmental benefit will be insignificant for reaching the target. • It does not distinguish between the various recovery processes, meaning that resource efficient and environmentally safe recovery cannot be given priority. Improved knowledge on C&D waste generation and handling, as well as on content and emissions of dangerous substances, is required to achieve a sustainable recovery.publishedVersio

Measurement and Modelling of the Spectral and Directional Reflection Properties of Lichen and Moss Canopies.

Abstract not availableJRC.(SAI)-Space Application Institut