Diffey Brian L, Mobley Curtis D
Dermatological Sciences, Institute of Cellular Medicine, University of Newcastle, Newcastle, UK.
Sequoia Scientific, Inc., Bellevue, WA, USA.
Photodermatol Photoimmunol Photomed. 2018 Sep;34(5):298-301. doi: 10.1111/phpp.12381. Epub 2018 Apr 17.
BACKGROUND/PURPOSE: The purpose of this paper is to estimate the contribution to our erythemal exposure at the coast of solar ultraviolet (UV) both reflected from, and transmitted into, the ocean.
The reflection of solar UV radiation from, and transmitted into, seawater was calculated using a numerical model under a number of atmospheric conditions to estimate erythemal exposure on the skin of supine/prone and ambulant people.
The results were expressed as UV Indices. Even under the most extreme insolation with the sun directly overhead, where the ambient UV Index may be around 14, reflected UV from the ocean contributes an erythemal exposure to the skin equivalent to a UV Index of about 0.7. For typical ocean waters, with the sun high in the sky, the UV index within the water is about 7 at a depth of 2 m.
Whilst our eyes often sense a high level of reflected sunlight from the ocean, especially when the sun is low in the sky, our skin does not share that experience. The reason people get sunburnt at the seaside has more to do with the absence of shade than with reflectance by the water surface or even beach sand.
背景/目的：本文旨在评估海洋反射及透射的太阳紫外线（UV）对我们在海边时红斑暴露量的贡献。
利用数值模型计算了在多种大气条件下太阳紫外线从海水中的反射及透射情况，以估算仰卧/俯卧及行走人群皮肤的红斑暴露量。
结果以紫外线指数表示。即使在太阳直射头顶的最极端日照条件下，此时环境紫外线指数可能约为14，但海洋反射的紫外线对皮肤的红斑暴露量相当于约0.7的紫外线指数。对于典型的海水，当太阳高悬天空时，水下2米深处的紫外线指数约为7。
虽然我们的眼睛常常能感觉到从海洋反射的强烈阳光，尤其是当太阳低空照射时，但我们的皮肤却并非如此。人们在海边被晒伤的原因更多地与缺乏遮蔽物有关，而不是与水面甚至沙滩的反射率有关。
