Department of Dermatology, University of Wisconsin, Madison, WI, USA.
Photochem Photobiol. 2012 Sep-Oct;88(5):1037-47. doi: 10.1111/j.1751-1097.2012.01099.x. Epub 2012 Feb 21.
Biologically, light including ultraviolet (UV) radiation is vital for life. However, UV exposure does not come without risk, as it is a major factor in the development of skin cancer. Natural protections against UV damage may have been affected by lifestyle changes over the past century, including changes in our sun exposure due to working environments, and the use of sunscreens. In addition, extended "day time" through the use of artificial light may contribute to the disruption of our circadian rhythms; the daily cycles of changes in critical bio-factors including gene expression. Circadian disruption has been implicated in many health conditions, including cardiovascular, metabolic and psychiatric diseases, as well as many cancers. Interestingly, the pineal hormone melatonin plays a role in both circadian regulation as well as protection from UV skin damage, and is therefore an important factor to consider when studying the impact of UV light. This review discusses the beneficial and deleterious effects of solar exposure, including UV skin damage, Vitamin D production, circadian rhythm disruption and the impact of melatonin. Understanding these benefits and risks is critical for the development of protective strategies against solar radiation.
从生物学角度来看，光（包括紫外线）对生命至关重要。然而，紫外线照射并非没有风险，因为它是导致皮肤癌的主要因素。过去一个世纪的生活方式改变可能影响了对紫外线损害的天然保护，包括由于工作环境而导致的我们的阳光暴露的变化，以及防晒霜的使用。此外，通过使用人造光延长“白天”时间可能会破坏我们的昼夜节律；关键生物因素（包括基因表达）的日常变化周期。昼夜节律紊乱与许多健康状况有关，包括心血管、代谢和精神疾病，以及许多癌症。有趣的是，松果体激素褪黑素在昼夜节律调节以及防止紫外线对皮肤的损害方面都发挥作用，因此在研究紫外线的影响时，这是一个需要考虑的重要因素。本综述讨论了阳光照射的有益和有害影响，包括紫外线对皮肤的损害、维生素 D 的产生、昼夜节律紊乱以及褪黑素的影响。了解这些益处和风险对于制定针对太阳辐射的保护策略至关重要。
