Short Wave - A Smarter Way To Use Sunscreen

Episode Date: June 26, 2023

Sunscreen: we should all be using it, but we might not all be using it the right way. In fact, the type of sunscreen you use may not be nearly as important as using it effectively. With the help of a few expert dermatologists, NPR science correspondent Allison Aubrey cues Scientist in Residence Regina G. Barber into six common mistakes to avoid when using sunscreen and how to stay safe in the sun this summer. Have a science fact you can't stop thinking about? Email us at [e-mail]! We'd love to hear from you. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, shortwavers, Regina Barber here with NPR's science correspondent Alison Aubrey. Hey, Allison. Hey, Regina, great to be here. So we're well into one of my favorite seasons, summer. And in my part of the world in the Pacific Northwest, it's goodbye to clouds and rain. And now there's more people outside, hiking, biking, in the sun. It's wonderful.

It's fun, right? It's so nice. And when we're in the summer and we're seeing the sun, that means it's time to revisit a topic we do a lot when the weather gets warmer. The science behind sunscreen and the best way to protect our skin from that sun. Yeah, this one never gets old, Regina. I kind of feel it's some of the most important information to get out there is how to apply sunscreen for maximum protection. And yet, yet it turns out that a lot of people are still doing it wrong, making mistakes. That's not good because the dangers of not protecting yourself from the sun.

sun are serious. It helps us protect against skin cancer, right? That's exactly right. And every year, over 80,000 people in the U.S. are diagnosed with melanoma. More than 8,000 people die from this type of cancer. And there's millions of cases of basal cell and squamous cell carcinoma, diagnosed each year two, and about 90% of these skin cancers are linked to the ultraviolet radiation from the sun. Ooh. And sunscreen plays a key role in protecting the skin. But you found out recently that a lot of people are making mistakes when they use it. I mean, I hope I'm not, but I bet I am. Yeah, you know, people seem to put a lot of thought into what type of sunscreen they buy, how high they want the SPF to be, whether they want spray, lotion, chemical, mineral.

But it turns out which sunscreen you choose may not be nearly as important as avoiding six very common mistakes that people make when it comes to applying sunscreen. Okay, so today on the show, we're going to hear about six common mistakes and how to avoid them. Plus, we get into which sunscreens may be better than others. You're listening to Shortwave from NPR. Okay, Allison, sunscreen mistake number one. What is it? Using old sunscreen. I've done it myself. How about you? Yes.

You know, a couple weeks ago, I was rummaging through my last season's pool bag and I found a few bottles of half used sunscreen. I'd figure, okay, let's just use this. I mean, why not? You paid 10 bucks for it. But then I spoke to Ida Arengo. She's a dermatologist at Baylor College of Medicine, she persuaded me to toss it out. I always tell people that you need to look at the expiration date and get rid of them. And even if they haven't expired, my kind of mantra is every spring I buy all new sunscreen for my household. Wow. She says the active ingredients can degrade and she says bacteria can get into the creams too. So several dermatologists told me that each season they throw out the old, buy new. It may seem wasteful, but the cost of not

protecting your skin properly is much higher. Okay, so let's talk about the active ingredients a bit. What are they? You know, there's a whole list of compounds that the FDA calls acceptable active ingredients for sunscreen. These include chemicals like oxybenzone, avobenzone. You can go to the FDA website to get a complete list. And these are chemical sunscreens that form a kind of thin protective film on the skin that absorbs UV radiation. If you're using one of these sunscreens, you're You need to make sure it's marked broad spectrum because there's actually two types of UV radiation that you need to protect yourself from, UVA and UVB, and a broad spectrum chemical sunscreen will protect you against both. And most products these days are broad spectrum. But there's also some concern that chemicals in the sunscreen might be harmful, right?

That's right. And I would say there's some uncertainty about the safety of these chemicals, or at least some of them. Recent studies have shown some of these compounds are absorbed into the bloodstream. But the impact of absorption isn't really well understood. The FDA has been conducting a safety review and has asked industry for more data. For now, the FDA has said that there is inadequate data to support a safety finding for some of the chemicals that are common in sunscreen like oxybenzym. Now, there's no evidence of harm, so there's no kind of definitive answer on that. And most dermatologists say the risks from a sunburn far outweigh,

on the potential risk of sunscreen chemicals. But is there an alternative? You know, if you are concerned about these chemicals and sunscreen, there are alternatives. You can choose what they call physical sunscreen or also referred to as mineral sunscreen. These are typically made from zinc oxide and titanium dioxide. They stay on the surface of the skin and physically block the sun. and that's why you kind of see that lifeguard effect of the white glaze on someone's face. I spoke to Dr. Tola Oyesanya.

She's a dermatologist at Kaiser Permanente in the Baltimore area. And she recommends this type of sunscreen to lots of her patients. I think that zinc oxide and titanium dioxide are much, much safer than chemical sunscreens. Because they're so inert, they're less likely to enter the bloodstream. She also says they're better for people with sensitive skin. and they might not lead to breakout. You know, older versions of these mineral sunscreens went on as kind of that thick white paste,

which some people don't like. Now there are some colorful versions, say bright pink. And there's also a lot more zinc oxide products available now that go on much clearer. And a good reason for choosing these mineral sunscreens, especially if you're going to the ocean, is that the National Oceanic and Atmospheric Administration, Noah says sunscreens without chemicals are better for coral reefs and marine life.

Okay, Allison, so what's another mistake people make? Not applying enough. Do you know how much you really need? I really don't. I apply some to my face every day, and I hope it's enough. Okay, well, you know, a lot of people spend time worrying about the SPF, but a sunscreen with an SPF of 15 will block out 93% of the UV rays, and when you bump it up to SPF 30, you're blocking out about 97%. So Dr. Oriasanya says the sunscreens with the highest sun protection factor, like the 80s or the hundreds, aren't necessarily better. SPF 30 is sufficient. And that's because SPF 30 is going to filter 97% of the UV rays that are coming through from the sun. And as we go up in SPF, SPF 50, SPF 75, SPF 100,

you're really getting a minuscule increase. She basically tells her patients, look, focus less on the SPF and more on the amount of sunscreen. Here's Dr. Ida Arengo again, the dermatologist from Baylor University. She says the recommended amount is about an ounce and a half of liquid sunscreen. We always say it's like a shot glass full of sunscreen is for the whole body. And then about a teaspoon for the face. Oh my gosh. I actually do do this in the morning.

Allison, I feel so good. And do you do the shot glass for the body? I do not. I think that's where a lot of people fall down. And when it comes to spray sunscreens, another little thing that can trip people up is that it can be tricky to gauge the amount. Right. I think that spray sunscreens are a bit risky because of the spray is easy to miss a whole area of your body. Yeah.

So she says make sure that all the parts of your body that you need to be covered feel. wet after you spray. And that brings us to a third mistake. Ooh, what is that? Assuming that one application of sunscreen will last you all day. Many people think that a higher SPF lasts longer, but that's just not true. So I spoke to Dr. Jennifer Holman. She's a fellow at the American Academy of Dermatology. She says sunscreens just don't last very long, especially when people sweat and swim. If you're exposed to the water, even with sunscreens labeled as water resistant, you're really only getting about 80 to 90 minutes of protection. So she says you really just need to remember to reapply sunscreen every couple of hours, even on cloudy days. I always forget that, always. Yeah, I mean,

dermatologists told me that they see some of the worst sunburns linked to overcast days because people just assume they don't need it. You're still getting about 80% of the UV rays filtered through those clouds on a cloudy day, so you absolutely can still, you know, experience damage from UV radiation on a cloudy day. So that's another kind of. common mistake people make, if it's cloudy, they just don't think they need it. And we're talking about everyone, right? Like, all humans are at risk of skin cancer from sun damage. That's right. I mean, sunscreen protection is recommended for all groups, I mean, with the exception of babies under six months. And that's because infants are more susceptible to rashes from sunscreen. They're also much more

likely to get a sunburn. So the FDA says for infants, the best thing is just to keep them out of the sun entirely, especially during the hours of 10 to 2 when the sun is strongest, or when they are outside, to have on lots of protective clothing, so, you know, long sleeves, a hat, keep them in the shade. For everyone else, it doesn't matter how dark or how light your skin is. Everyone should protect themselves from the sun's radiation. Dermatologists say fair-skinned people are at higher risk of burns and melanoma, but people with dark skin are vulnerable to damage from the sun too. I mean, I've cut skin cancers off of every skin type that I can think of because that risk is still there. And Dr. Oya-Sanya told me that she advises people with darker skin who've had a lot of sun exposure to be careful to check their palms.

The soles are their feet, their nails inside their mouth because these are all the areas that people can develop skin cancer because there's less melanin in those areas. It's a little alarming, but okay, I think we have one more common mistake to cover, right? Yeah, and this goes to where you store your sunscreen. It should be somewhere that is cool and dry. Dr. Oriyosanya says, do not keep it in the glove compartment of your car. Oh, no, no. I know. It's horrible because things need to be convenient, but you're sort of trading the convenience of keeping it in the car with, uh-oh, like, what if these chemicals start to degrade?

Now, it's not going to happen overnight if you're going on a week-long camping trip or something. Probably fine to just leave it in the car. But as a rule of thumb, you want to. keep the sunscreen in a cool, dry place. The sunscreen is actually being degraded by heat, and so the components of the sunscreen that are supposed to protect you are getting broken down slowly over time. So one thing you can keep in your car is clothing or hats to shield you from the suns, like a baseball cap that will protect part of your face.

Dermatologists say, what's better is a three-inch brim hat made with tightly woven material that will give you more protection from the sun's rays. And parasols. Yes, umbrellas, perfect. And umbrellas. Okay, Alison, thank you so much for bringing us this very important information. I learned a lot. Let's lather up and enjoy the summer.

Thanks, Regina. This episode was produced by Carly Rubin and edited by Jane Greenhalsh and Rebecca Ramirez. It was fact-checked by Allison and Jane. Robert Rodriguez was the audio engineer. Beth Donovan is our senior director and Anya Grunman is our senior vice president of programming. I'm Regina Barber. Thanks for listening to Shortwave, the science podcast from NPR.