该不该担心防晒霜渗入血液?

A recent study found that some chemicals in sunscreen can be found in your blood after just a day of applying them liberally, but don't freak out just yet-sunscreen is still considered safe to use, and you don't even necessarily need to switch brands.

最近的一项研究发现：涂完防晒霜一天后，部分化学物质会进入血液，但不要惊慌--防晒霜还是安全的，而且也没有换品牌的必要。

Is it bad for sunscreen to be absorbed through the skin?

防晒霜被皮肤吸收是件坏事吗？

Not necessarily. We've known for a long time that it can be absorbed, so this isn't news. FDA rules assume that some absorption can happen, but that if levels are above 0.5 ng/mL, extra safety studies should be done. The new study established that, yes, levels can get this high if you apply a ton of sunscreen.

不一定。很久以前我们就已经知道防晒霜会被吸收，这已经不是新鲜事儿了。美国食品药品监管局（FDA）的指标表示，防晒霜会在一定程度上被吸收，但如果超过0.5 ng/mL，则需进一步开展安全研究。新研究表明，是的，如果大量涂抹防晒霜，吸收水平的确会高达0.5 ng/mL。

How much sunscreen are we talking about?

大量涂抹防晒霜的定义是什么？

People in the study used way more sunscreen than any of us do in real life. Researchers followed the directions that we're all "supposed to" follow, applying two milligrams of sunscreen per square centimeter of skin, and then applying that same amount again and again throughout the day. Realistically, most of us apply a quarter to half that amount at a time, and reapply less if at all.

研究中，受试者涂抹的防晒霜量比现实生活中人们的涂抹量多得多。研究员遵循了我们所有人"都应"遵循的方向：每平方厘米的皮肤涂抹2毫克的防晒霜，然后一整天都按照这一用量反复涂抹。而实际上，大多数人一次只会涂0.5至1毫克，如果反复涂抹的话，用量也会更少。

Should I stop using chemical sunscreens?

我该不该停止使用化学防晒霜？

You should definitely keep using sunscreen, since its benefits are pretty well established, and nothing about this study suggests that sunscreen is dangerous-just that it's not as well understood as we thought.

当然应该继续使用。涂抹防晒霜的好处是公认的，而且这项研究并没有表明涂抹防晒霜有危害--只是它并没有如我们预期那般被理解。

If you're concerned, one option is to use titanium oxide or zinc oxide sunscreens, whose components are not absorbed into the skin. They have their own downsides, though: a thick layer of these sunscreens can give skin a white cast, and they may not protect as well against the entire UV spectrum.

如果你还是心存忧虑，那可以选择使用氧化钛或氧化锌防晒霜，这些成分不会被皮肤吸收。但这些成分也存在弊端：涂抹厚厚的一层会使皮肤假白，对紫外的防护效果也一般。

Dr. Anjali Mahto, dermatologist and author of The Skincare Bible, summed it up well when she wrote on Instagram: "Personally, I won't be changing my pattern of use or product based on the findings above-whilst the study is interesting, it certainly does not reflect how I use my sunscreen in real life."

安佳丽·马赫托（Anjali Mahto）医生在Ins上进行了总结："个人层面而言，我不会因为上述研究而改变我的使用模式或产品--虽然这项研究很有趣，但它并没有确切反映出我在现实生活中使用防晒霜的情况。"