Humans have been exposed to solar UV radiation since their appearance on Earth and evolution has enabled most individuals to adapt to this exposure, to some degree. UV radiation produces several deleterious effects in human skin and light-skinned individuals are at greatest risk for both acute and long-term negative effects such as DNA damage, sunburn, immune suppression and skin cancer. The benefits of photoadaptation, which leads to a decreased response after acclimatization, are that humans who have skin that is capable of photoadaptation can work and play in the sun with reduced fear of painful sunburn. However, the effects of photoadaptation on DNA damage and development of skin cancer are quite complex and less well-understood. In this article, we have reviewed the current state of knowledge of UVR photoadaptation in human skin. However, more studies are needed to explore the use of UVR photoadaptation to protect against critical endpoints, such as skin cancer.

中文翻译：

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影响人类皮肤中UVR光适应的机理和变量

自从人类出现在地球上以来，人类就已经暴露在太阳紫外线辐射之下，并且进化使大多数人在某种程度上能够适应这种辐射。紫外线辐射会对人的皮肤产生多种有害影响，皮肤白皙的人极有可能遭受急性和长期的负面影响，例如DNA损伤，晒伤，免疫抑制和皮肤癌。光适应的好处是适应皮肤的人可以在阳光下工作和玩耍，而减少了对痛苦的晒伤的恐惧，这种适应作用导致适应后的反应减少。但是，光适应对DNA损伤和皮肤癌发展的影响相当复杂，人们对它的了解还很少。在本文中，我们回顾了人类皮肤中UVR光适应的当前知识状态。然而，