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.
Is it bad for sunscreen to be absorbed through the skin?
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。很久以前我們就已經知道防曬霜會被吸收，這已經不是新鮮事兒了。美國食品藥品監管局（FDA）的指標表示，防曬霜會在一定程度上被吸收，但如果超過0.5 ng/mL，則需進一步開展安全研究。新研究表明，是的，如果大量涂抹防曬霜，吸收水平的確會高達0.5 ng/mL。
How much sunscreen are we talking about?
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.
Should I stop using chemical sunscreens?
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.
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.
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."