IRA FLATOW: This is Science Friday. I’m Ira Flatow. Microplastics– you know, it seems like just yesterday that environmental scientists were raising the alarm about the tiny beads of plastics in face wash. And now these tiny invisible polymer particles seem to have wormed their way into everything else on Earth– our water, our shellfish, even our beer.

Perhaps it was only a matter of time before we found them in ourselves. That’s right. We are full of microplastics. And here to explain more and chat about other selected subjects in science is Popular Science senior editor Sophie Bushwick. Nice to have you back.

IRA FLATOW: Nice to be here.

IRA FLATOW: So let’s talk about this. Where exactly did researchers find these microplastic?

SOPHIE BUSHWICK: So researchers had a group of eight subjects from countries all over Europe and Asia. And they essentially had these subjects keep a food diary for a week. And then at the end of the week, they took a stool sample from themselves and sent it to the researchers. And then the researchers had the fun job of picking through that.

They were looking for 10 different types of plastic. And they found these plastic types. They found nine of them. And they were in all of the samples.

IRA FLATOW: Stool samples, so they go right through our bodies.

SOPHIE BUSHWICK: Yes. We eat them, and then we send them out the other end.

IRA FLATOW: Only a matter of time, right, with all the microplastics that are around us?

SOPHIE BUSHWICK: Right. Researchers have found microplastics in tap water, in beer. It’s in seafood. Because a lot of these plastic fragments get into the waterways. And then the fish eat them, and we eat the fish.

The other thing is that a lot of us drink water from plastic bottles or food out of plastic takeout containers or that’s been wrapped in plastic. And there’s all sorts of chances for fragments to come off. So the definition of a microplastic is that it’s smaller than five millimeters. But it can be much, much smaller than that. Some of these fragments are on the nanometer scale.

IRA FLATOW: And we suspect that there is no harm coming from these.

SOPHIE BUSHWICK: Well, it’s very difficult to tell. Because it’s hard to sort of parse out. You can’t really feed some people plastic samples and not feed other people plastic samples at this point. It’s just not ethically feasible.

But it’s too hard to tell. Maybe they’re just passing us harmlessly. It’s also possible that they could be accumulating and that a lot of these plastics carry chemicals that they might leech into the human body.

So I wouldn’t tell people– I would say don’t panic. Because it could be yes. It could be that they’re harmless. But it’s very difficult to tell at this point.

IRA FLATOW: Those of us of a certain age always thought that asbestos was harmless also back in the day. So let’s keep our eyes open. Some good news though. Maybe eating organic vegetables is linked to less cancer.

SOPHIE BUSHWICK: That’s right. A study in France, they looked at almost 70,000 people. They had them answer a survey how often they had organic food and whether they had cancer. And then the researchers followed up in five years to check in again on whether they had developed cancer.

And they also took a lot of other information, such as how often they drink or smoke, how often they eat fruits and veggies, how much they exercise, and also their income level. And what found is, with a couple of specific types of cancer like non-hodgkin’s lymphoma and post-menopausal breast cancer, people who eat organic did have less of a risk of developing those cancers.

IRA FLATOW: So was it actually tied to the vegetables themselves, or could it have been the kind of lifestyle you live if you eat organic vegetables?

SOPHIE BUSHWICK: It’s really difficult to say because organic produce is more expensive in the United States. It’s about 45% more expensive than conventional. And it’s also– people who do eat organic tend to have other healthy lifestyle factors. They eat a lot of fruits and veggies. They exercise more often.

And because they’re wealthier, being wealthy just comes with a whole bunch of health benefits. You’re more likely to afford health care and to go to the hospital for more frequent screenings. So that means if you do get cancer, they can catch it earlier and treat it.

IRA FLATOW: Sounds to me like you would need a better designed study to sort of eliminate those other factors if you’re going to do it.

SOPHIE BUSHWICK: They did take the subjects’ income level, and they tried to sort of factor out some of these other confounding factors. But it’s just incredibly difficult to peel apart all the different things that go into human health.

IRA FLATOW: We’ve been talking about that for ever since I’ve been doing this. Yes, no, maybe, whatever.

SOPHIE BUSHWICK: Well, that’s why nutritional studies are so tricky. Because it’s possible that there’s so many other factors involved than just the one that they’re studying.

IRA FLATOW: Yeah, all right, let’s move on to a factor that’s made the weather terrible for some people. Hurricane Willa made landfall on Mexico’s Pacific coast last week. And what was really interesting about this, the last minute shifts in intensity, right?

SOPHIE BUSHWICK: Right. Over the course of just two days, Willa went from a tropical depression to a category 5 hurricane. We’re talking from 40 mile-per-hours winds to 160 mile-per-hour winds.

IRA FLATOW: And do we know how or why that could happen so suddenly?

SOPHIE BUSHWICK: Conditions were just perfect for it. It was going over an area with warm water, and heat fuels hurricanes. It was also in an area with a lot of moisture.

And there wasn’t a lot of wind shear. Wind shear is just when you’ve got wind at different speeds at different altitudes. And that kind of thing can really dissipate a storm.

And Willa didn’t encounter any of that as it was building to a category 5. But after that, it did. It actually went back down to a category 3 before it made landfall.

IRA FLATOW: Very quickly also.

SOPHIE BUSHWICK: Yes. It was a really quick change.

IRA FLATOW: Is this sort of a new pattern then, for hurricanes, to be expected?

SOPHIE BUSHWICK: It’s hard to say. I think that it’s part of a pattern of more hurricane intensity, definitely. So Willa is actually the 10th hurricane this season to reach category 4 or 5 in the Pacific Northeast. It’s the most intense season that area has had ever on record. So it’s definitely– I mean, researchers have warned that in a warming planet, the hotter it gets, the more intense we can expect hurricane season to be.

IRA FLATOW: And you know, with all the water that these hurricanes drop now, maybe we need a new classification. People have been talking about, well, the wind speed may not just be adequate enough to describe.

SOPHIE BUSHWICK: I completely agree. As a matter of fact, most people who die in hurricanes, they die from fresh water flooding, not from wind damage. And the category system only really talks about wind damage. So I think it is important to talk about flooding.

So Willa has made landfall. It moved from Mexico to Texas. And apparently, the moisture is going to be affecting the mid-Atlantic states over this weekend. We could be in for our first nor’easter of the season. And it’s getting fuel from this hurricane. So it’s just affecting, in terms of precipitation, a big chunk of the US.

IRA FLATOW: Yeah, we’re gonna get out of here early today. Talking about water, we’re learning more about what kind of life Mars could support. Talking about water on Mars. We’re always talking about water there.

SOPHIE BUSHWICK: It’s very exciting that there is water there. So researchers, when they found liquid water on Mars, they knew that water had to be really salty. Because Mars can get very, very cold. And in order for that water to not freeze, it must have a high salt concentration.

So they didn’t really look at whether life might have enough oxygen. But a new study has done just that. They said, well, if we have this very salty water at this range of temperatures and at these different pressures, how much oxygen would dissolve in that water?

Would it be enough to support microbes that could breathe it? And they found it would be. It would have enough oxygen to support not only microbes but certain types of sponges.

IRA FLATOW: Sponges.

SOPHIE BUSHWICK: Sponges on Mars.

IRA FLATOW: Wow, not the cellulose kind.

SOPHIE BUSHWICK: No, so sponges are this model organism. And researchers like to– it’s very simple. It’s a filter feeder. It’s probably one of the first animals to have evolved. So it’s a great thing for researchers to look at it and be like, huh, I wonder if this could survive there.

IRA FLATOW: Maybe in those moons of Jupiter we find sponges living there.

SOPHIE BUSHWICK: That would be really amazing.

IRA FLATOW: That would be great. And it’s amazing. It’s always amazing to have you, Sophie.

SOPHIE BUSHWICK: Thank you.

IRA FLATOW: Sophie Bushwick, senior editor at Popular Science.

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