نتایج جستجو برای: solar uvr
تعداد نتایج: 120675 فیلتر نتایج به سال:
Marathon runners spend considerable time in outdoor training for and participating in marathons. Outdoor runners may experience high solar ultraviolet radiation (UVR) exposure. South Africa, where running is popular, experiences high ambient solar UVR levels that may be associated with adverse health effects. This feasibility study explores the use of personal dosimeters to determine solar UVR ...
introduction: ultraviolet (uv) radiation affects human organs such as skin, eyes and immune system, as well as animals and plants. the main natural source of uv radiation is the sun. to study the effects of solar uv radiation there is a need to quantify variations of solar energy received on the earth surface at different intervals. materials and methods: to measure uv radiation a broadband fib...
Exposure of human skin to low doses of solar UV radiation (UVR) causes increased pigmentation, while chronic exposure is a powerful risk factor for skin cancers. The mechanisms mediating UVR detection in skin, however, remain poorly understood. Our recent studies revealed that UVR activates a retinal-dependent G protein-coupled signaling pathway in melanocytes. This phototransduction pathway le...
A substantial loss in the stratospheric ozone layer due to anthropogenically released chemicals has aroused concern about the effects of increased solar ultraviolet radiation (UVR), particularly UV-B (280-315 nm), on the Earth’s surface. Solar UV-B radiation is detrimental for most sun-exposed organisms, including humans. They can penetrate deep into biologically significant depths in lakes, po...
Climate change and variation in atmospheric ozone are influencing the intensity of ultraviolet radiation (UVR) reaching ecosystems. Changing UVR regimes, in turn, may alter epidemics of infectious disease. This possibility hinges on the sensitivity of epidemiologically relevant traits of host and parasite to UVR. We address this issue using a planktonic system (a zooplankton host, Daphnia denti...
Solar ultraviolet radiation (UVR, 290-400 nm) is a crucial environmental factor in alpine lakes because of the natural increase of the UVR flux with elevation and the high water transparency of these ecosystems. The ecological importance of UVR, however, has only recently been recognized. This review, examines the general features of alpine lakes regarding UVR, summarizes what is known about th...
The detrimental effects of excess personal solar ultraviolet radiation (UVR) exposure include wrinkles, immunosuppression and skin cancer. Approximately 1 000 South Africans die each year from melanoma skin cancer and 30% of all histologically-diagnosed cancers are skin cancers, including the non-fatal non-melanoma skin cancers. Individuals with minimum natural protection from melanin, includin...
Many workers perform their daily activities outdoors undertaking different postures and many anatomical body sites are UVR exposed. This paper aims to compare the anatomical distribution of the solar erythemal UVR to the higher half of the body for farm workers during their usual working activity in agriculture. This research was carried out in the experimental farm“Azienda Agraria Didattico-Sp...
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 ch...
IntroductIon Sunlight is the primary source of ultraviolet radiation (UVR) to which humans are exposed. Although a portion of the sun’s UVR is absorbed by the ozone layer of the atmosphere, significant UVR penetrates the ozone to strike the surface of the earth. For most people, the total amount of UVR received (the cumulative dose) increases linearly over time.1 Documentation that cumulative s...
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