Mantas Grigalavicius1, Johan Moan1,2, Arne Dahlback2, Asta Juzeniene1. 1. Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway. 2. Institute of Physics, University of Oslo, Oslo, Norway.
Abstract
BACKGROUND: Solar ultraviolet (UV) radiation varies with latitude, time of day, and season. Both spectral UV composition and ambient UV dose lead to different health outcomes at different latitudes. Finding the optimal time for sun exposure, whereby the positive effects of UV exposure (vitamin D) are facilitated and the negative effects (skin cancer, photoimmunosuppression) avoided are the most important consideration in modern skin cancer prevention programs. OBJECTIVES: This paper focuses on the latitude dependency of UVB, UVA, vitamin D production, and skin cancer risk in Caucasians. METHODS: Biologically effective UVB (280-315 nm) and UVA (315-400 nm) doses were calculated using radiative transfer models with appropriate climatologic data for selected locations. Incidences of squamous cell carcinoma (SCC) and cutaneous melanoma (CM) were retrieved from cancer registries and published articles. RESULTS: Annual doses of UVA radiation decrease much less with increasing latitude than annual doses of UVB. Incidences of CM also decrease less steeply with increasing latitude than incidences of SCC. As SCC is caused mainly by UVB, these observations support the assumption that UVA plays an important role in the development of CM. The variations in UVA (relevant to CM) and UVB (relevant to vitamin D production) over 1 day differ: the UVB : UVA ratio is maximal at noon. CONCLUSIONS: The best way to obtain a given dose of vitamin D with minimal carcinogenic risk is through a non-burning exposure in the middle of the day, rather than in the afternoon or morning.
BACKGROUND: Solar ultraviolet (UV) radiation varies with latitude, time of day, and season. Both spectral UV composition and ambient UV dose lead to different health outcomes at different latitudes. Finding the optimal time for sun exposure, whereby the positive effects of UV exposure (vitamin D) are facilitated and the negative effects (skin cancer, photoimmunosuppression) avoided are the most important consideration in modern skin cancer prevention programs. OBJECTIVES: This paper focuses on the latitude dependency of UVB, UVA, vitamin D production, and skin cancer risk in Caucasians. METHODS: Biologically effective UVB (280-315 nm) and UVA (315-400 nm) doses were calculated using radiative transfer models with appropriate climatologic data for selected locations. Incidences of squamous cell carcinoma (SCC) and cutaneous melanoma (CM) were retrieved from cancer registries and published articles. RESULTS: Annual doses of UVA radiation decrease much less with increasing latitude than annual doses of UVB. Incidences of CM also decrease less steeply with increasing latitude than incidences of SCC. As SCC is caused mainly by UVB, these observations support the assumption that UVA plays an important role in the development of CM. The variations in UVA (relevant to CM) and UVB (relevant to vitamin D production) over 1 day differ: the UVB : UVA ratio is maximal at noon. CONCLUSIONS: The best way to obtain a given dose of vitamin D with minimal carcinogenic risk is through a non-burning exposure in the middle of the day, rather than in the afternoon or morning.
Authors: Miguel Rivas; Elisa Rojas; Gloria M Calaf; Marcela Barberán; Claudio Liberman; Marcelo De Paula Correa Journal: Oncol Lett Date: 2017-03-23 Impact factor: 2.967
Authors: Hanna Abrahamsson; Sebastian Meltzer; Vidar Nyløkken Hagen; Christin Johansen; Paula A Bousquet; Kathrine Røe Redalen; Anne Hansen Ree Journal: BMC Cancer Date: 2021-05-11 Impact factor: 4.430
Authors: Stefan Pilz; Winfried März; Kevin D Cashman; Mairead E Kiely; Susan J Whiting; Michael F Holick; William B Grant; Pawel Pludowski; Mickael Hiligsmann; Christian Trummer; Verena Schwetz; Elisabeth Lerchbaum; Marlene Pandis; Andreas Tomaschitz; Martin R Grübler; Martin Gaksch; Nicolas Verheyen; Bruce W Hollis; Lars Rejnmark; Spyridon N Karras; Andreas Hahn; Heike A Bischoff-Ferrari; Jörg Reichrath; Rolf Jorde; Ibrahim Elmadfa; Reinhold Vieth; Robert Scragg; Mona S Calvo; Natasja M van Schoor; Roger Bouillon; Paul Lips; Suvi T Itkonen; Adrian R Martineau; Christel Lamberg-Allardt; Armin Zittermann Journal: Front Endocrinol (Lausanne) Date: 2018-07-17 Impact factor: 5.555
Authors: Alois W Schmalwieser; Barbara Klotz; Michael Schwarzmann; Dietmar J Baumgartner; Josef Schreder; Günther Schauberger; Mario Blumthaler Journal: Photochem Photobiol Date: 2019-06-06 Impact factor: 3.421
Authors: Jenna R Chalcraft; Linda M Cardinal; Perry J Wechsler; Bruce W Hollis; Kenneth G Gerow; Brenda M Alexander; Jill F Keith; D Enette Larson-Meyer Journal: Nutrients Date: 2020-07-27 Impact factor: 5.717
Authors: Mark P Little; Martha S Linet; Michael G Kimlin; Terrence Lee; Zaria Tatalovich; Alice J Sigurdson; Elizabeth K Cahoon Journal: Environ Health Date: 2019-12-27 Impact factor: 5.984