Solar radiation and human health

Abstract

The Sun has played a major role in the development of life on Earth. In Western culture, people are warned against Sun exposure because of its adverse effects: erythema, photoimmunosuppression, photoageing, photocarcinogenesis, cataracts and photokeratitis. However, Sun exposure is also beneficial, since moderate doses give beneficial physiological effects: vitamin D synthesis, reduction of blood pressure and mental health. Shortage of Sun exposure may be even more dangerous to human health than excessive exposure. Avoiding Sun exposure leads to vitamin D deficiency which is associated not only with rickets and osteomalacia, but also with increased risk of cardiovascular disease, multiple sclerosis, rheumatoid arthritis, diabetes, influenza, many types of cancer and adverse pregnancy outcomes. Solar radiation induces nitric oxide release in tissue and immediate pigment darkening which certainly play important roles, although these are still unknown. Action spectra relevant for health are described. We will also review what is known about spectral and intensity variations of terrestrial solar radiation as well as its penetration through the atmosphere and into human skin and tissue.

Evaluating meso-scale change in performance of several databases of hourly surface irradiation in South-eastern Arabic Pensinsula

“…Hourly SSI is the irradiation received during one hour. The SSI plays a major role in many domains such as weather and climate (Abdel Wahab et al, 2009;Blanc et al, 2011Blanc et al, , 2015Lefèvre et al, 2007), ocean (Bell et al, 2009), agriculture (Bois et al, 2008a), forestry (Colombo et al, 2009), ecology (Wagner et al, 2011), oenology (Bois et al, 2008b), human health (Juzeniene et al, 2011), energy (Kenfack et al, 2009;Szabó et al, 2011), or architecture (Leloux et al, 2012;Rotar and Badescu, 2011). Current means for SSI assessment are ground-based instruments which may offer high to good quality measurements if well attended but are too few to offer the coverage needed in space and time.…”

Short- and long-term variability of spectral solar UV irradiance at Thessaloniki, Greece: effects of changes in aerosols, total ozone and clouds

“…Although ultraviolet (UV) radiation is only a small fraction (< 10 %) of the total solar radiation that reaches the Earth's surface, it is vital for the life on Earth (Asta et al, 2011;Häder et al, 2015;Lucas et al, 2015;UNEP, 2010;Williamson et al, 2014). The amount of solar UV radiation reaching the atmosphere is changing periodically due to changes in the Earth-Sun distance and the solar activity.…”

Biologically effective surface UV climatology at Rome and Aosta, Italy

“…However, small amounts of UV radiation have beneficial effects since they stimulate the production of vitamin D in the human body. In addition several recent studies suggested the possible protective role of vitamin D in some neoplasias of internal organs [1]. The latitude extension and the variety of environmental conditions of the Mediterranean as well as of the Alpine regions make solar UV measurements an important issue in Italy [2] where, however, a climatological characterization of biologically effective UV radiation is still missing.…”