DAVID GREENE, host:
This is MORNING EDITION from NPR News. I'm David Greene.
STEVE INSKEEP, host:
And I'm Steve Inskeep.
Today in Your Health it is the unofficial start of summer. You know, that time of year when people start thinking about sunscreen and dehydration and bugs. NPR health correspondent Allison Aubrey thinks about these things a lot. But when she came by to report on them in our studios she had a problem.
ALLISON AUBREY: You know, I don't want to do the story here, Steve.
AUBREY: I feel like I'm in a cave. It's dark. It's windowless. Let's get outside.
INSKEEP: I'm not going to say no to that.
AUBREY: All right. Want to go to the park?
AUBREY: Let's go.
(Soundbite of birds chirping)
INSKEEP: Oh, it's beautiful up here. We're on the top of this ridgeline overlooking Washington, D.C. The Washington Monument is down there. Somewhere over there is the Capitol. And it's sunny.
AUBREY: And the sun is overhead.
INSKEEP: Directly overhead.
AUBREY: So do you have sunscreen on?
INSKEEP: You kidding me?
AUBREY: All right. Let me just say - I'm not going to be preachy here. I think we all know that if you burn your skin you're going to damage the cells and over time that could increase the risk of skin cancer. But I think what we need to do here is a little demonstration.
AUBREY: So I've got some props. This, as you can see is a…
INSKEEP: A shot glass.
AUBREY: Shot glass.
INSKEEP: I think you've got a really interesting recommendation for how to deal with hot weather. I like this.
(Soundbite of laughter)
AUBREY: Well, hold on here a second. And we've got some sunscreen. Now, when I talked to dermatologist Darryl Regal, who practices in New York, here's what he told me about the amount of sunscreen you need to use.
Dr. DARRYL REGAL (Dermatologist): A shot glass is an ounce. So that's what it should take to cover your whole body if you're at the pool.
AUBREY: Do you think people really follow this?
INSKEEP: A full shot glass of sunscreen? Probably not. It's all greasy and icky and gross.
AUBREY: All right. So we're going to put the icky and greasy stuff right here into the shot glass. More or less that is about an ounce, all right?
AUBREY: So I'm going to pour this into your palm.
INSKEEP: Could I have a potato with my sour cream? Ok. Pour it into the palm. My gosh.
AUBREY: Certainly people are not going to go through this drill every time. But as a demonstration it's sort of interesting to do once to see how much sunscreen you really need.
INSKEEP: Ok. So that's the first rule. Use a lot. Use more than you think you need to. But what about the type of sunscreen that you choose?
AUBREY: You know, here's the deal. You want a sunscreen that's got both UVA and UVB protection. For a long time we thought that UVB was the thing we wanted to protect ourselves from, so the SPF factor in sunscreens that refers to the protection from UVB rays.
INSKEEP: Is that the number on there like 10 or 15…
INSKEEP: …or whatever it is.
AUBREY: SPF 15, sun protection factor 15.
INSKEEP: The higher the number the better?
AUBREY: More protection. Now we've realized that both UVA and UVB rays are damaging. So the FDA has this new system, which they've yet to finalize, where they're actually going to put a star system - a star ranking onto sunscreen bottles, with four stars being the best. That would suggest you get the broad spectrum, as they call it, UVA and UVB ray protection.
INSKEEP: That would be like a movie rating. That's great. I loved it. It was better than "Cats." It was great. Ok. Let me ask about another thing. We've dealt with sunscreen here. What about if you're spending a lot of time in the sun or even at the beach the concern of dehydration?
AUBREY: You know, technically you're really not dehydrated 'til you lose about two percent of your body weight. Now for us, that's going to take some time. So for small children, that happens a lot more quickly. For athletes it can happen more quickly. And I talked to a pediatrician at Stanford, Chris Longhurst, and he said this is the question that he gets from parents a lot.
Dr. CHRIS LONGHURST (Stanford): That by the time a child feels thirsty, is he or she really already dehydrated. And the answer actually is absolutely, yes.
AUBREY: So the idea here is that kids need to be drinking a lot. For athletes, the American College of Sports Medicine actually says before you go out for a practice on a hot day, start drinking two hours before you go out. And then when you're on the field, drink about 10 ounces - a little more than a cup -every 15 or 20 minutes.
INSKEEP: So let's talk about what I should drink. Should it just be water, like this bottle of water I've got here? Or is Gatorade ok? Anything else?
AUBREY: Well, you know, we all have this built-in cooling system, so when we sweat all that evaporating perspiration helps us cool down. So, yeah, you've got to replace the fluid somehow, and water is the number one way you want to do that.
You know, with Gatorade there is some evidence that if you do intense workouts - and I'm talking about being out there for more than an hour in the heat -that there can be some benefit to replacing electrolytes, too. But when I talked to Chris Longhurst about it - that's the pediatrician from Stanford - he says the problem with these Gatorades and PowerAdes is that there's just a lot of sugar in them.
INSKEEP: Ok, Allison. So let's remind people. We're out in this beautiful park. It's a beautiful sunny day. We've got our sunscreen. We've got our water. And what about bugs?
AUBREY: Have you noticed that when you're outside in the summer some people seem to be bitten by mosquitoes from head to toe? Other people aren't bothered at all?
AUBREY: Well, actually this effect is real. I talked to researcher - his name is Ulrich Bernier and the USDA, U.S. Department of Agriculture - and he says that some people are more attractive to mosquitoes.
Mr. ULRICH BERNIER (U.S. Department of Agriculture): The reason that some people are more attracted to mosquitoes than others has to do with the chemicals that each of these people or each individual's producing. Different people tend to emit chemicals at different levels coming off of their skin. And some of these chemicals that we produce attract mosquitoes to us. And some of these chemicals that we produce actually hide us from mosquitoes.
AUBREY: So he went on to explain this has to do with your diet. Also exercise can make a difference. For instance, when you release lactic acid after you exercise that seems to attract mosquitoes.
INSKEEP: Wait a minute, if you exercise more, you get bitten more?
AUBREY: Well, here's the deal. The research is sort of at a halt because they can't find precisely what are the mix of these different chemicals that are going to attract and repel.
INSKEEP: So bug bites are annoying for those of us who are tasty to the bugs, but are they actually dangerous?
AUBREY: Well, do you remember West Nile virus?
INSKEEP: I remember the stories about it, yeah.
AUBREY: Well it's not in the headlines now, but it's still here and it's still real. I talked with Emily Zielinski-Gutierrez. She's from the Centers for Disease Control and Prevention.
Dr. EMILY ZIELINSKI-GUTIERREZ (Behavioral Scientist, CDC): West Nile virus has not disappeared. In fact, in 2008, we saw over 1,300 human cases reported to CDC, and we know that that was only a fraction of the cases that occurred. We did have 44 fatalities. And if you think of each of those as preventable -that's really important - that can pretty much ruin your summer. That's worth balancing out with a couple of minutes to put insect repellant on when you go outdoors.
AUBREY: Most people I know are going to contract a virus than being bitten by a mosquito, but you'd probably rather be safe than sorry.
INSKEEP: Some people trying to be safe will have the same question that they have about sunscreen: Are there some that work, some repellants, bug repellants that work and others that don't?
AUBREY: The CDC has given its nod to three types of repellants in addition to DEET. There's the Avon products that are called Skin So Soft Bug Guard. That's got a chemical in it called IR3535. That's effective. There's also a Picaridin products. One of the products that contain Picaridin is called Cutter Advanced. There's also an ingredient derived from lemon eucalyptus oil, a product called Repel Pump Spray has got this in it. And Emily Zielinski-Gutierrez says it's maybe kind of a pungent smell. She said with any of these products, you want to test on your skin first before applying it to your entire body.
INSKEEP: Alison Aubrey, since we are out here on a sunny day, I just want to mention you've got a lovely, very stylish pair of sunglasses on. What should I look for in a pair of sunglasses in this…
AUBREY: You know, probably not these. If you take a look at these, nowhere on there do you see anything about UVA or UVB protections.
INSKEEP: But they're very pretty. They wrap around the face. They've got some kind of a wing on the side. I mean, isn't this everything you should ever want from sunglasses?
AUBREY: I'm glad they get your nod as a fashion statement, but you know what? There's a couple of things to look for in sunglasses. Some sunglasses are made of polycarbonate, and that's just the material that does filter out 99 percent of UVA and UVB rays. Other sunglasses like these, plastic ones, they could be dipped in a chemical to cut the UVA, UVB radiation. That would make them effective. I actually talked to Dr. Wayne Bizer. He's an ophthalmologist from Florida, and he says it's important to know whether your glasses have this UV ray block.
If they don't, he explains what happens is when you go out on a bright day, the sunglasses may be filtering out all this visible light so you're not squinting, and so the eye senses it's still dark, and then your pupils start to open up a bit.
INSKEEP: You can get hurt worse?
AUBREY: That's what he says. Here he is.
Dr. WAYNE BIZER (Ophthalmologist): A cheap pair of sunglasses can diminish the amount of visible light that enters the eye, fooling the eye, which allows the pupil to dilate a little bit. If there's no UVA and UVB protection in that lens, then what's happening is you're allowing more UVA and UVB to enter the inside of the eye.
INSKEEP: Alison, there are times when I'm looking at a rack of sunglasses and I see those little stickers saying there's the UV protection on there. I wonder if I should even believe those.
AUBREY: I asked Bizer about this. I said there is some kind of seal of approval that we can trust? And unfortunately, the answer is no.
INSKEEP: So in the end, we're just going to have to take a chance and go out in the sun.
AUBREY: You know, life is risky.
INSKEEP: Alison Aubrey, thanks for getting me out to the park here today.
AUBREY: I am so glad you came out here with me, Steve. Thanks so much.