Sun exposure (UVB, UVA, and blue‐violet visible light) in ordinary daily situations

Abstract

Sun exposure (UVB, UVA, and blue-violet visible light) in ordinary daily situations Dear Editor, Solar radiation is essential to human life; in addition to promoting warmth and well-being, it interacts with biological tissues causing metabolic changes, oxidative stress, and deoxyribonucleic acid (DNA) mutation. Different wavelengths elicit specific effects in the skin, such as sunburn, erythema, vitamin D synthesis, carcinogenesis, immunosuppression, photoaging, modulation of skin microbioma, and melanogenesis. 1,2The intensity of solar radiation that reaches the skin varies with altitude, latitude, the season of the year, reflective surfaces (e.g., water, grass, or snow), shadow, clothing, sunscreen use, length of exposure, and the time of day. Furthermore, the biological effect of sun exposure in the skin differs individually according to melanin pigmentation, genetic predisposition (e.g., the ability to repair DNA), photosensitizing drugs, antioxidant capacity, and skin disorders that are influenced by solar radiation. [3][4][5][6]

Foreword

“…and environment (presence of snow, water or pollutants). 3 The balance between exposure to the moderate sun radiation necessary for life and to excessive radiation leading to skin damage is fragile. 4 Indeed, UV radiation is now widely known to have harmful effects on the skin: it can lead to genotoxic damage, either directly through DNA strand breaks or indirectly through oxidative stress on macromolecules including nucleic acids, proteins and lipids.…”

“…14,15 In addition to wearing protective clothing and seeking shade, applying sunscreens remains essential in many circumstances to protect the skin from the negative effects of the sun while taking advantage of the positive ones. 2,3,14 Until very recently, the organic UV filters contained in sunscreens provided insufficient protection of the skin from the harmful effects of visible light. 16,17 Moreover, the safety and environmental impact of some of these organic filters has been called into question.…”

“…Our skin is directly exposed to solar radiation, the type and the intensity of which vary according to several parameters, such as location (latitude and altitude), time (season and moment of the day), position (sun/shadow, outdoor/indoor, distance from a window, inside a car, etc.) and environment (presence of snow, water or pollutants) 3 . The balance between exposure to the moderate sun radiation necessary for life and to excessive radiation leading to skin damage is fragile 4 .…”

“…Recent recommendations issued by two panels of international experts have highlighted the need for better protection against solar radiation, including against visible light, as well as for additional training/education for healthcare professionals and patients on the use of photoprotection and the impact of visible light on overall skin health 14,15 . In addition to wearing protective clothing and seeking shade, applying sunscreens remains essential in many circumstances to protect the skin from the negative effects of the sun while taking advantage of the positive ones 2,3,14 . Until very recently, the organic UV filters contained in sunscreens provided insufficient protection of the skin from the harmful effects of visible light 16,17 .…”

Update on Melasma—Part II: Treatment

“…Large amounts of radiation reach the skin even in the shade or near windows, while UVA and VL pass through windshields and window glass. Moreover, these wavelengths occur at melanogenic levels from 08:30 until 17:30 in intertropical areas [8,9].…”