防晒霜到底怎么选？看完这篇科普再也不迷茫了_时事

防晒霜到底怎么选？看完这篇科普再也不迷茫了

防晒是一年四季都不能偷懒的护肤步骤，更是夏日护肤的重中之重。相信许多小仙女都知道涂防晒霜的必要性，但你真的对防晒霜足够了解吗？你知道UVA和UVB的区别吗？选择防晒霜应该注意哪些指标？一起来看看皮肤科医生的专业建议。

UVB rays

中波紫外线

“People think that SPF equals everything,” says Dr. Roopal Kundu, a dermatologist at Northwestern University Feinberg School of Medicine. And it does count for a lot: the sun protection factor measures a sunscreen’s ability to filter UVB rays, which are related to sunburn and skin cancer. But SPF only measures UVB rays; it doesn’t tell you anything about protection from UVA rays, Kundu says.

西北大学费因伯格医学院皮肤科医生昆都称：“人们认为防晒系数代表一切。”防晒系数的确很重要：它衡量的是防晒霜过滤中波紫外线的能力，中波紫外线与晒伤和皮肤癌有关。但防晒系数仅表示过滤中波紫外线的能力，它并不代表任何防护长波紫外线的能力。

UVA rays

长波紫外线

The most misunderstood part of sunscreen is UVA. “UVA is around every day; it can penetrate through window glass,” she says. Like UVB, it’s also related to an increased risk of skin cancer, but unlike UVB, it’s not filtered by the ozone at all, Kundu says. UVA doesn’t cause sunburn, but “it really leads to darkening and aging, because it penetrates deeper into the skin and has more influence in the collagen.”