Listener supported WNYC Studios. Is it just me or does it feel like there have been a lot of food recalls lately? We live in a system of probability. We can only have a certain level of confidence that the food supply is safe. It's Friday, December 13th, and you're listening to Science Friday. I'm Sci-Fry producer Rasha Aridi. It seems like every day there's a new food recall. Granola bars here, veggies there. But are instances of food recalls actually going up or does it just feel like it?
Later in the episode, a food scientist will walk us through the ABCs of a food recall, and if there's actually been a wave of them this year. But first, let's check in on this week's science news. Here's Sapphira's Kathleen Davis. There's still a lot to be learned about the physics of our universe. And one of the most perplexing ideas is an observation made around a decade ago that the universe seems to be expanding faster than it should be.
Now two years of James Webb Space Telescope data. Back up that finding. Joining me now to talk about that and other topics from the week in science news is Casey Crownhart, climate and technology reporter at MIT Technology Review. Welcome back to Science Friday, Casey. Thanks so much. Great to be here as always. Great to have you. So explain this story to me. The universe is expanding too fast. What does that mean?
I know this one, as most space stories do, broke my brain a little bit. So basically, there are a couple of different ways that we can kind of measure or observe how fast the universe is expanding. One of them is by kind of looking back. at the earliest light from...
just after the Big Bang, basically, and then doing calculations based on our understanding of how the cosmos works. Another way is to take space telescope data, look at things that are very far away, stars, supernovas, and you can tell how far... way they are and how fast they look to be moving. The problem is that those two ways of observing and measuring the expansion of the universe don't line up. And we've, like you said, we've known that since the Hubble Space Telescope, but now...
The James Webb Space Telescope really confirmed that. So now we can't really blame Hubble anymore and think that it's just some like instrument error. It looks to be a real problem. So when we say too fast, we're talking about... in the context of our own understanding of the universe, right? Absolutely. Yeah. So it's anything that we're talking about, like huge time scales, huge length scale.
It's significant. It's like about 8% faster, I think, than what it quote unquote should be. But it's significant. So if we have confirmation that it wasn't just some telescope error, where does that leave physicists? Yes, with a lot of questions to answer. So there are definitely theories about where this might be coming from. Some of the leading ones are that...
dark matter or dark energy have something to do with this. These are things that we know exist in the universe, but are sort of invisible to us. We just kind of infer them based on... how they affect regular matter and energy. So that is kind of a leading theory, but there's a lot of research to be done still, for sure. Okay, I'm going to keep us on the head-scratching topics for just a little bit longer. Quantum computing.
Google made an announcement this week about quantum computing. Tell me about this. Yes, definitely in the same category of brain breaking. So Google announced this week that it has a new quantum computing chip called Willow. And there are two really interesting things about this new chip. One is that it's capable of performing a computing challenge.
in less than five minutes, whereas today's the world's fastest supercomputers would take longer than the age of the universe to do the same kind of work. The other thing that's really interesting about this is that they were able to do error correction in a really...
interesting way. So one of the big problems that's keeping quantum computers from being useful is that the universe is a really noisy place and things like the movement of electrons and like atomic effects can introduce errors into quantum computing. So the other interesting thing about this, this Google chip announcement is that they showed that as they built bigger computers or bigger quantum chips, they were able to correct errors.
Do we have any idea if this is something that Google is going to save for themselves and do quantum Google-y things? Or are they maybe planning to sell this technology to other people? That's a great question. They didn't say in their blog about this what exactly the plans are. But I mean, to be fair, we're still pretty far from this being.
useful. I mentioned that this is better at correcting errors than most quantum computers are, but it's still way, way, way off from doing things like solving algorithms or doing good simulations of chemistry, which are some things that quantum computers might eventually be used for. So we've still got a long way to go with the research here.
Okay, so let's move on to some more concrete electronics. You have a story for us from this week about improving the electronics of prosthetic devices, right? Yes. So this is a really interesting story in Wired this week. Phantom Neuro is an Austin-based startup that's trying to provide more lifelike control of prosthetic limbs. So basically what this company is doing is they want to build a thin, flexible muscle implant.
that they could put inside a limb and that would allow amputees to have a wider, more natural range of movement. And also it would have a faster response time. So this would be a lot better than current prosthetics at basically acting more like a biological limb.
So there are other groups that are trying to do more neurological control directly in the brain, right? How does this compare to those things? Yeah, so this would be basically implanted in the muscle, so kind of close to where the amputation is. In theory, it could be...
less risky than doing a brain implant. Messing with the brain is like, what's going on there? And so this could be a little bit easier and less risky of a surgery and of a process. But also this company hasn't actually done implants yet. just announced data testing out kind of a wearable version of their device, which they did show worked pretty well. But the next stage, which they want to do next year, is start to do these implants to see how they really work.
What kind of prosthetics have they made or do they plan to make in terms of parts of the body? Oh, yeah. So the test that they did was an arm and they want to do this with kind of upper limb amputees. And so they were able to kind of have people doing, you know. opening and closing their hand, moving their wrist around, stuff like that. So ARMS is kind of the target for this first test. Well, great. Well, let's hope that that technology advances to where people need it.
Let's pivot away from electronics to some climate news. There's... been kind of an Arctic climate report card that's come out with some, as you might imagine, some bad news about the tundra, right? Yes, the news is not great in the Arctic. Based on this data, researchers are able to say kind of for the... first time definitively that for the past 20 years, the tundra has been emitting more CO2 carbon dioxide than it has removed. This is different from what's been happening for the last...
thousands of years, usually the Arctic tundra locks away more carbon than it emits. You know, plants grow, they soak up carbon dioxide as they grow, they get buried in the soil. And that kind of gets locked away. And that's a great thing for climate change because we want less of that carbon dioxide in the atmosphere warming up our planet.
But as temperatures have risen, in part because of human activities and fossil fuels, temperatures have started to thaw the tundra. So microbes are kind of active, breaking down that stored plant matter. There are wildfires. yeah, we're seeing that the kind of balance has flipped in the Arctic. Is this report card
all bad news or is there maybe some good news here? Definitely a lot of bad news, but there are some glimmers of good news, which I always love to look for. So ice seal populations around Alaska that have been challenged by rising temperatures. Those populations look to be pretty healthy. There was also a pretty cool winter, which helped Greenland's ice sheet.
shed the smallest volume of ice in over a decade, which is exciting. But to be clear, you know, it's still melting. It's just melting slower than it has. So good news, but things are definitely serious. Okay, we'll take it with a grain of salt. Let's shift gears here. We've been hearing a lot recently about bird flu, H5N1. And it's not just in birds, it's in cattle as well. But now there's news about a testing program for milk.
Yes. So this is the first mandatory testing program. The USDA announced it this week. So for about nine months, we've seen the virus, H5N1, spreading through dairy cows. And there have been some states that have started testing for this to really understand where dairy herds are being affected and to what extent. But now we'll have a mandatory testing program starting with just six states, but it should expand.
hopefully help researchers get a better handle on where this virus is spreading and how. Do we know what's going to happen when a test comes up positive? Poultry farms, for example, we've heard that there's been a ton of culling of animals. Would that possibly happen here too? Yeah, it's a really different situation because when birds are affected, it can be really deadly for them.
Cows seem to very rarely die from infection, so I don't know that that's very likely. I think that really the main goal right now is just tracking and understanding. The virus is... It's possible that it's spreading to humans through cows. We don't really know if infected milk is able to infect humans. But it's possible that if the virus goes through mammals, it could become more dangerous for humans. So just getting a better understanding is I think really the key thing here.
Well, we'll definitely be keeping an eye out on that news into the new year. But let's shift to some more positive animal news. There's been work towards protecting the monarch butterfly. Tell me about this. Yes. So the U.S. Ocean Wildlife Service is adding monarch butterflies to the threatened species list by the end of next year. It's kind of bad news, but we've known for a long time that monarch butterflies, we've seen populations going down. And so this status would basically...
like you said, help protect the butterfly. It would prohibit people from killing or transporting it. There would be kind of restrictions around what people can do with milkweed, which is an important food source for monarchs. And it would sort of protect some of their key habitat in California. So would this actually like lock away habitat from development?
Because this would list them as a threatened species and not an endangered species, it's not quite as strict. But yeah, those 4,000 acres in coastal California, there would be kind of restrictions and like certain rules around development. So it definitely would affect some people, but it's not quite as strict.
A lot of things are potentially going to change with this new political climate that we're entering into. Is this something that might be affected by a new administration? Yeah. So this actually this announcement opens up a public comment period of about nine.
days. And so after that, the agency can kind of lock this in or tweak it or cancel it. So it's not a done deal just yet. And we'll have to watch. The agency has until the end of next year if they decide to do it to actually make this final. Okay. So finally, our last story, we're going to move from butterflies to moths and a story about how they can actually listen to plants, Casey. Yes. I wish I were a moth because I would love to.
be able to listen to what my houseplants say to me, like what I'm doing wrong. I'm thirsty. Literally. So yes. Researchers have known for a while that some plants, when they're under stress, they make noises. They make ultrasonic clicks. So these aren't something that humans can hear, but some animals can, including some insects. And now researchers found that...
some moths are able to hear those sounds and interpret them as clues to decide where to lay their eggs. So basically the researchers put two healthy plants on kind of either end of a room. Both were thriving, both were hydrated. but they played the sounds of a dehydrated, not very happy plant from one of those. And the moths avoided that one. Even though it was totally fine, it sounded like it wasn't. And so they really tended to...
prefer the healthy plant that wasn't making any distress noises. The idea here is that, you know, the healthy plant will be able to nourish their eggs. It'll provide a good food source. So they're really going for the healthy plants here. They want the best home that they can possibly get.
That's what researchers think is happening with this. They're listening skills. Thank you so much, Casey. Always appreciate your time. Thanks so much for having me. It was great to be here. Casey Crownhart, climate and technology reporter at MIT Technology Review. After the break, are there really more food recalls this year? Stick around, we'll get into it. Support for Science Friday comes from the Alfred P. Sloan Foundation.
working to enhance public understanding of science, technology and economics in the modern world. It feels like there's been an onslaught of food recalls this year. We've seen recalls for items like cucumbers and carrots, deli meat and smoked salmon, foods that have been contaminated with salmonella, E. coli, listeria.
and more. As a consumer, it can be stressful and even scary to keep up with food recalls. So today, we're going to break down how a food recall happens, if there are actually more recalls this year than in other years. and some food safety tips. Joining me to help us break this down is my guest, Dr. Byron Chavez, food scientist and associate professor at the University of Nebraska-Lincoln. Welcome to Science Friday. Thanks. Happy to be here.
So first off, is there actually a giant wave of food recalls this year? That's a great question that we've been getting pretty frequently these days. And I would say no. I would argue that if we look at the data... that we haven't really seen a spike in food recalls compared to previous years if we statistically compared the data. I think that recently what's been happening is that the recalls that we've had have been very heavily publicized.
like there's a lot more of those recalls happening. So walk me through how a food recall happens. What is the first step? Yeah, totally. So typically, either the company that produces the food or a state or federal agency discovers that there's something wrong, right? It could be that the product is directly contaminated, or there is suspicion that the product might be.
be contaminated. And so at that point, companies will work directly with state and federal agencies to determine what is the level or the class of recall that has to happen. And that is based on the risk associated with the potential hazard. And then those federal and state agencies will do some advertising. And that is when we see things in the news, we hear things on the radio, it goes on social media, just to warn the consumers that that product should not be.
But it typically starts with testing something or reviewing records and identifying that something may have gone wrong. And so when we're actually talking about contaminations, are we talking about a contamination on the surface of the food or grown into the food or both? It could be any. It could be that some contamination is typically external. So if we think about whole fruits and vegetables, so we typically see external contamination. But if we had something like fresh cut fruit, then...
Of course, that contamination is already in the flesh, and so it's a little different. Think about meat products that have been tenderized versus meat that has not been tenderized, right? So in the tenderized version, we might have pathogens inside of the... tissue, but in the intact version, the pathogens would only be on the surface. So it could be a number of different things.
Okay, so let's get into how these recalls actually work. So let's say that I eat a carrot that's coated in E. coli here in New York, and then someone else does the same in Alaska, and we both get sick. How do federal agencies connect those illnesses back to a common product?
Yeah, that's a great question. And that's where the epidemiological system really comes in. So the first thing that would have to happen, really, is that the two people that got sick actually get sick enough that they seek medical attention. And that is one of the reasons.
why so many of these instances of foodborne illness are never captured because we might get sick, but not severely enough that we have to go to the doctor. And so if two people go to the doctor because of a foodborne illness and they get... and that microbe is identified, then that goes into a national database. And then we can start seeing clusters of people that get sick. And that is where federal agencies like the CDC will come in and try to put two and two together.
And we start asking people, what did you eat? And that is how federal agencies will put those two cases together and then potentially declare an outbreak. But it really starts with seeking medical attention. So one thing I was surprised to learn was that about half of the cases of foodborne illness comes from tainted produce. I would have thought that the majority would be from things like meat and eggs. So why is produce so germy? Yeah.
Great point, right? And so we do see that the ecology of foodborne pathogens changes over time, right? And so we used to have a lot of issues with foods of animal origin. So you mentioned meat and poultry and eggs. And a lot of those... problems have switched to minimally processed foods. And so we typically want things like fresh produce. We want to have fruits that are maybe exotic and we want to have them year round. And so that has put a lot of pressure in intensifying.
agricultural systems. And so that also has put a lot of pressure into importing food commodities, because we want to have them all year round.
Produce has become one of these things where we see a lot of issues because they do come from naturally contaminated environments. Obviously, we do a lot of... of things to prevent direct contamination of that food product on the farm and stuff like that with irrigation water, with biological soil amendments of animal origin, all of those things we really try.
But let's keep in mind that a lot of these foods come from natural environments that are open to wildlife, to different sources of water, and that they can become contaminated fairly easily. What are the most common food contaminants and how can they affect the body? Yeah, we hear about those all the time. Things like salmonella. E. coli, Listeria monocytogenes. So these are big names of microbes, right? And so something that I really want to point out is that when we think about E. coli,
There's lots of different types of E. coli, and most of them actually will never cause illness, right? So we have E. coli in our gastrointestinal tracts. So a lot of those types of E. coli are the good ones. But we have a group. of E. coli's that are highly pathogenic. And so that is when we see things like shigatoxin-producing E. coli that are really scary names.
Think about Salmonella, Pathogenic E. coli, and Listeria monocytogenes as the big ones. They can cause anything from diarrhea and fever and sometimes vomiting to some very serious illnesses. Pathogenic E. coli, the one that we saw in the onion outbreak associated with McDonald's. Right. So that one, it's particularly dangerous. That one can cause.
Bloody diarrhea, kidney failure can make you go on dialysis the rest of your life. You could potentially need a kidney transplant, right? So those microbes are extremely serious. There are others that are really serious only for... groups of population, such as Listeria monocytogenes is particularly problematic for pregnant women, for immunocompromised individuals. But for a healthy adult, it might just be fever or feeling a little unwell.
Same with salmonella. If we get salmonella, we'll have probably a couple of days that you're going to have diarrhea, potentially vomiting, fever, but it's going to be self-limiting. And so let's keep in mind that while all of these microbes can be...
pathogenic, meaning that they can cause illness, that the severity will largely depend on the immunological status of the host. And so that is when we make differentiations between a healthy adult versus somebody that's immunocompromised versus children.
and the elderly, as well as pregnant women. And I would assume that these recalls can be really expensive for companies. So I'm assuming that they're pretty careful about contamination. Yes. Something that we really need to keep in mind is that... Companies don't want this to happen, right?
Companies don't want to be associated with that really bad PR. They don't want to have to spend money recalling products. And so they do go through programs where they do mock recalls, right? So they can determine internally what is the percent.
of their product that it's currently in the market that they can recover if they had to recall a food product. And so they go through these exercises. They work very closely with federal agencies, with state agencies. And like you mentioned, recalls can be... very expensive. It is estimated that it can be, depending on the depth of the recall, anywhere from $100,000 to $10 million, right? So if you have products that are
everywhere in the country may be placed in markets abroad. You still have to take care of those. And so the liability is really high. How good would you say the USDA and the FDA are at catching contaminated foods? They're very good. I would argue that they are very, very good, right? That doesn't mean that there's still a lot of opportunities for improvement. But both of those federal agencies that you mentioned are the two main food safety agencies really in the country, right?
We think about USDA for meat, poultry, and processed eggs, as well as catfish, and then for the FDA for pretty much everything else. And so they have certain capacities and also they have certain limitations. In the case of the FDA, for example, we have relatively new regulation that allows the FDA to mandate a recall. So they can tell a company, you must. remove this product from the market.
whereas the USDA does not have congressional authority to do that. And so they can only pass voluntary recalls. Of course, they have other mechanisms that they can apply so that companies remove products from the market. But in that case, all of the recalls end up being voluntary. It is in the best interest of the company to voluntarily recall a product because you don't want consumers to get sick with your product.
So from what I can understand, these recalls can sound scary, but they're also a sign that the food safety system is working, right? Yeah, you know, this is debatable, right? A lot of people, if you ask somebody else, maybe they would give you a different answer, but I would really lean...
Towards, yes, we see these recalls and we know that the system is working because we are able to catch contamination. Of course, we catch contamination all throughout the food supply from primary production, whether that's for animals or... produce and then through transformation and processing and manufacturing and distribution.
as well as at the end point, right, for retailers. There's contamination that it's been discovered all throughout, and that is a sign that the system works because that... product never actually makes it to the pantries of the consumers. But there is certainly... a proportion of product that will always be contaminated and that poses a risk because we live in a statistical world, right? Like we live in a system of probability.
And catching contamination is a statistical process. We can only have a certain level of confidence that the food supply is safe. And while we have a very, very safe and robust food safety system, there's always opportunities for contamination. So we are almost out of time here, but before we go, can you leave us with a few food safety tips? Maybe like three rules that I should follow. Absolutely. You know, the ones that we give all the time.
wash your hands. That's a typical one you want to prevent cross-contamination. You want to make sure that foods that are hot should be hot, foods that are cold should be cold. And in the case of wrinkles, I really would say... Read the labels. Look at the news. I would say subscribe.
to federal agencies, social media platforms. So if you think of the FDA, the CDC, the USDA, they will keep you informed. So keep an eye open and an ear open for news of products that are being recalled so that you protect yourself and your family. Byron, thanks so much for joining me. This was a great conversation. Awesome. Thank you for having me. Dr. Byron Chavez is a food scientist and associate professor at the University of Nebraska in Lincoln.
On Monday's episode, how environmental destruction and the pursuit of empire go hand in hand. Lots of folks helped make this show happen, including Jason Rosenberg, George Harper. Shoshana Buxbaum. Sandy Roberts. Have a great weekend. I'm Rasha Aridi.