Woodhead A D, Setlow R B, Tanaka M
Brookhaven National Laboratory Upton, New York 11973, USA.
J Epidemiol. 1999 Dec;9(6 Suppl):S102-14. doi: 10.2188/jea.9.6sup_102.
We discuss the role of sunlight, mostly ultraviolet light (UV), in the induction of nonmelanoma and melanoma skin cancer. Whilst the former seems to be correlated with accumulated exposure, the causation of melanoma is more complex, and may also involve the pattern of, and age at, exposure. The efficacy of sunscreens is debatable; while they protect against UVB wavelengths (290-320 nm), and so extend the time that may be spent in the sun before becoming sunburnt, their use may subject wearers to excessive exposure to UVA (320-400 nm) and visible light. Both epidemiological surveys and experiments with animal models suggest that UVA, and perhaps the visible, may induce melanomas. Although Japanese have a much lower incidence of skin cancer than Caucasians, the dramatic rise in skin cancer in Japanese-Americans in Hawaii exposed to high-intensity irradiation raises concerns. If the Japanese people adopt sun-seeking behavior, or should the levels of UV irradiation rise significantly through depletion of the ozone layer, then this could become an important health problem in future.
我们讨论阳光，主要是紫外线（UV），在非黑色素瘤和黑色素瘤皮肤癌诱发过程中的作用。虽然前者似乎与累积暴露相关，但黑色素瘤的病因更为复杂，可能还涉及暴露的模式和年龄。防晒霜的功效存在争议；虽然它们能抵御UVB波长（290 - 320纳米），从而延长在晒伤前可在阳光下停留的时间，但使用防晒霜可能会使使用者过度暴露于UVA（320 - 400纳米）和可见光。流行病学调查和动物模型实验均表明，UVA，或许还有可见光，可能诱发黑色素瘤。尽管日本人的皮肤癌发病率远低于白种人，但在夏威夷暴露于高强度辐射下的日裔美国人中皮肤癌发病率急剧上升，引发了人们的担忧。如果日本人养成寻求阳光的行为习惯，或者由于臭氧层损耗导致紫外线辐射水平显著上升，那么这在未来可能会成为一个重要的健康问题。
