Air Pollution: An Unclear and Present Danger
Science Talk
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Full episode transcript -

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welcome to Scientific American Science stock posted on November 21st 2019. I'm Steve Merci, Here's the beginning of a New York Times story from October 24th. New data reveal that damaging air pollution has increased nationally since 2016 reversing a decades long trend toward cleaner air. And here's a line from a BBC story dated November 4th. An Indian Health Ministry official said Delhi's pollution monitors did not have enough digits to accurately record pollution levels, but she called a disaster.

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Air pollution kills seven million people globally every year. It is not just causing asthma attacks, but, you know, heart attacks, strokes, premature birth.

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That's journalist and author Beth Gardner and her new book is Choked Life and Breath in the Age of Air Pollution recently called her at her home in London. After my 30 minute conversation with Gardner, stay tuned for a five minute segment sponsored by the Cavalier Prize with CRISPR, gene editing pioneer Jennifer Doubting and now Beth Gardner. So when I got your book, I saw that it was about air pollution, and my initial reaction was, that's and you know that's an old story. Ah, I'm I've been alive long enough. I remember the Clean Air Act and how Los Angeles Air was a joke on Johnny Carson every night and ah, I thought with climate change is the big environmental story, What's the big deal about air pollution right now? I mean, we see how bad Beijing is on TV sometimes. And then I read your book and I was really kind of blown away It at how vital and issue this still is and how the United States, obviously where I am, is not the whole story. And Beijing ain't even know nearly the worst of it. And the amount of human suffering and early mortality that we see from air pollution is really mind boggling. So is that kind of what you expected when you put a book out about air pollution?

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It wasn't what I expected before I started to learn about this. It's funny that you say that because I think I came to it in many ways with the same set of preconceptions. You know, I'm an environmental journalist. I cover health cover environmental stories. I live in London, which is a pretty badly polluted city, and it's not something that for a really long time was ever on my radar screen about. I guess it's seven years ago now because it's just it was just as the 2012 London Olympics were approaching, I was asked to do a story that was something to do with air quality Visa VI, the athletes that would be coming to London And in the course of reporting that I, you know, obviously had occasion to sit down at my computer and read a little bit of the science about air pollution. And I guess that was the moment that I experienced the shock that you may be experienced when you read my book. Because, you know, I think you're really write that This is not something that gets talked about a lot.

You know, we hear sort of environmental journalism covering rightly so. The climate crisis. Health journalists, I think, sort of focus on, you know, things like healthy eating, exercise, diabetes, all that stuff. And I think air pollution in some ways has fallen through the cracks and what I learned and that, you know, 10 minutes that I initially spent googling this for for a story I was working on was that air pollution kills. The World Health Organisation estimates seven million people globally every year. It is not just causing,

you know, asthma attacks, which I think we probably both would have been pretty ready to accept would be the case. Um, but, you know, heart attacks, strokes, premature birth, um, conditions like diabetes, dementia, obesity that I never would have sort of imagined would be connected to dirty air. And when I read those things, you know, as a journalist,

I think it started to hit me that this is a really big story, and it's a really important story, and, you know, we're none of us paying enough attention to it. It is actually now deeply intertwined with the climate story, which I think makes it even more consequential than it otherwise would be. But even without that connection, I mean seven million people a year, 100,000 Americans still dying from this where I live in the U. K. 40,000 premature deaths every year from air pollution, you know, that's that's a big story on its own. So I sort of began with a you know, I guess,

um on effort, a journey to try toe understand this. And, you know, you said something that's really true, which is that American air quality is dramatically better than it was when when the Clean Air Act was passed in 1970. So for the U. S, it is It is a story of progress, for sure. But, you know, we are not there yet way still have a long way to go. Yeah. I think that that a lot of people kind of think about air pollution and they think about places like Beijing. You know,

Chinese people wearing masks. They think about India, which actually has way worse air pollution than then China even does. But it's true that that this is ah, you know, a story that is of even larger proportions in poor countries in the developing world. But it's our story, too, in the U. S. And the UK, and this is something that's still, you know, killing people on baking us sick. And in the developed world, it's sort of invisible.

We don't see it, you know, unless you're a statistician who can kind of analyze, you know, death rates to compare them to pollution levels, you know? So I felt as a journalist. I wanted to find a way in the book to kind of try toe to make this story visible to

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people. Uh, tell the quick anecdote about Richard Nixon, who signed the Clean

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Air Act. Eso eso Nixon not only signed the Clean Air Act, you know, one of our most consequential laws, I think in modern American history and and the foundation of sort of American, you know, environmental and health protective law. He also created the Environmental Protection Agency, but Nixon was no environmentalist. He you know, he wasn't a very astute politician, and he could see which way the wind was blowing. He really signed the Clean Air Act in orderto sort of deny Ed Muskie, who everyone thought was gonna be his opponent in the next presidential election, to deny him kind of a cudgel to use against Nixon. You know who could criticize him on environment if he signs the Clean Air Act and created the E p. A.

But there's the funny story is that just before he died, one of his former aide said to him, You know, President Nixon, you'll go down in history as a great environmental president and Nixon said. God, I hope not. You know, this was not where his heart was, but he he felt the pressure because this was something Americans really cared about.

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Yeah, and you book really talks about the effect that a mass movement the public opinion can have on getting governments to do things?

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Yeah, and I think that that's a really important part of the air pollution story. And it's also a really important part of kind of the dynamic that we're in right now. You know, back in the late sixties, in 1970 you could see it. You could see the pollution in American air. You know you'd come home at the end of the day and your collar would be black from coal smoke in car exhaust. We've come so far now in terms of improving our air quality because of this law, that it's it's much less visible now. And I think that in some ways the Clean Air Act is in danger in that way of becoming a victim of its own success because that public support was a really important part of, you know, like we were just talking about what helped this law to get onto the

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books. Yeah, it's like the vaccine issue. You know that nobody has exactly these diseases in the developed world anymore. So people say, Why do you need these vaccines? Well, yeah, they're, like, you said, a victim of their own success. So, um, the material let's talk about Delhi in India because you went there and it's just so

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incredible. Yeah, it's horrendous. And I wasn't even there during the worst time of year. It can vary sort of seasonally and the really, you know, absolutely off the charts. Pollution in Delhi comes usually in the autumn in November because all the farmers in that part of India sort of up wind of of the capital. After they harvest their their wheat and stuff, they set their fields on fire and t clear the fields. And it creates this smoke that is so heavy that NASA photographs it from space and you can you could go online and see these images. It's just like black clouds heading towards the city of millions and millions of people, you know, and very predictably, because we know that this is exactly what the science tells us happens when air pollution spikes. Very predictably, death rates go up.

Hospitalizations, heart attacks go up, strokes go up. So I was there in the springtime, which is, you know, compared to that relatively cleaner. But, you know, it's really a year round problem. And the thing that kind of boggled my mind about Delhi is in most of the places that I went to, and in most parts of the world, they're sort of like one or two, really big, you know, polluters.

It tends to be obviously transportation cars and trucks, ships, and it's, you know, industry, whether that's power plants or factories. But in India, sure, they have those things. But there's There's just so many other contributors to the pollution to, you know, there's the farmer's fields, like I just described. There's garbage fires all over the city because they don't have regular trash collection. So the garbage just piles up, and then people set it on fire.

You know, people in the street, homeless people are burning wood, or sometimes even plastic or other garbage for heat. People all across India, Villagers air burning wood and, you know, cow dung for for their cooking. So there's so many different sources that are contributing to the horrendous air problem that they have. Um, and you know, that creates a real challenge in cleaning it up because you got to do so many things at once. And so far the Indian government has really, you know, failed to engage with this in any meaningful way. And the human consequences are horrendous.

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And you also have the the cook stove issue, which is it goes way beyond India.

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It does. But India, Israel sort of, you know, epicenter for that problem. And it's interesting because thes these dirty cook stoves, that's sort of more of a rural problem. You know, people who don't have access or money for better fuels like gas or electricity. And for a long time it was sort of, you know, cordoned off by scientists as a separate thing. This is they called it indoor air pollution and, you know, sort of regular old pollution from from cars and factories and stuff was considered outdoor pollution. But the latest research has actually started to shed light on the fact that these things were really deeply interconnected. So the indoor now they call it household air pollution thes dirty cooking fires.

Obviously, it has the most immediate effect on the people in the house, especially women doing the cooking and Children who tend to be around a lot during the day cause they're breathing the most concentrated fumes. But what what scientists now realise is that that though that smoke it doesn't just dissipate. It has a real impact on the air quality of the country as a whole, including big Indian cities. And it's now believed that these dirty cook stoves are contributing 25% of the total Indian air quality problem. So these things are really interconnected, and you know, that sounds kind of daunting. But I guess the other way to look at it is that if you give these Villagers access to a better way to cook, generally speaking, the quickest way to do that is gas, natural gas or some kind of L. P G or an electricity hook up that will not only have a huge benefit for their health in a very immediate way, but it'll actually really help Thio make progress on cleaning the air of the country as a whole.

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And just how much worse is Delhi's air than Beijing's air.

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You know it keeps changing because these numbers are constantly being updated. The most recent statistic that I remember seeing was that it was like 40% worse or something like that. And Beijing is actually really starting to make progress on this China as a whole. You know, they they're they tend to zigzag a lot in their policy. So the progress tends to be, you know, two steps forward, one step back, or sometimes even the other way around. But generally speaking, the Chinese government has really started to engage with this. And, you know, we were talking before about mass movements of people and how that can make politicians act. Obviously, China is not a democracy,

that the dynamics of sort of public opinion and political action are very different there than they are in Western country. But nonetheless the Chinese government, I think over the last sort of 68 10 years has really started to realize that this is something that people are concerned about, particularly the urban middle classes, who, if anybody has any kind of political voice in China, you know it's them and the government, I think, in an effort to, you know, kind of prevent this from becoming something that kind of gets people out into the street and becomes a focal point for anger that could even, you know, threaten stability, threaten the Communist Party's grip on power. The government has, I think,

tried to sort of forced all that by actually doing something about the problem, you know? So we've started seeing cold caps for certain regions of China. You know, there's questions on a nationwide basis of whether they're gonna have successfully plateau and start to reduce their coal use any time soon. But you know, in the in the regions where the pollution sort of been drifting to Beijing and the other big East Coast cities, we've been seeing real progress. And there were actually some numbers out pretty recently, indicating that Beijing's particle pollution these tiny particles that are the most dangerous to help, were down 60% this year, compared Thio. I think it was eight years ago because of of these actions that the government is taking and you know, of course, in order to reduce coal usage, they're starting to ramp up renewables, invest money in solar power in wind and now throwing a ton of money at electric vehicles. So they're going in the right direction. Andi, I think that's actually the biggest difference right now between China and India.

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You mentioned the particles that 2.5 m particles.

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Yeah, they're called PM 2.5. So that number refers to the size of the particle 2.5 microns, which is very, very tiny, you know, completely invisible and much, much smaller than even the width of a human hair. Thes particles sort of results whenever you basically burn anything, whether it's, you know, gas or diesel in your car's tank. Or, you know, would in a Indian village or or coal In the Polish power plan, there's all kinds of different pollutants and may all do bad things to you. But these particles are the most powerfully lake by this really now huge body of scientific evidence to very,

very powerful health impacts, and the reason is that they penetrate all the way into your body. Scientists have now found thes tiny particles in placentas. They found them in the cells of the heart and in brain tissue. So you know what that tells you is that the stuff that you're breathing that that we're breathing every day in, you know, in in cities around the world is really touching every part of our

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bodies. And you talk in the book and it's fairly obvious that, um, a lot of these conditions effect poor people a lot worse than they do well off people, even to the point of here in the States where the pollution is much better. I mean, it's far less bad, Let's say say it that way. If you live right next to the Cross Bronx Expressway, which is not a well off neighborhood, you get a lot more particular it's and noxious gases in your lungs and the rest of your body than you do if you live even 200 yards away.

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Yeah, exactly. That's really true. And I think that that is a really important dynamic and it's a really important part of the air pollution story, and it holds true almost everywhere. I mean, I saw that in Delhi, and I saw it in L. A and the San Joaquin Valley in California. It's true in London where I live, you know, and the way I put it in the book is that this is sort of a double stranded dynamic. Air pollution hurts everybody who breathes it, right? So l A has high levels of, you know, ozone and particles as a region as a city wide on the city wide basis.

And everyone who lives there will be affected by that. But it also affect some people more than others. And, you know, we can all guess who's gonna end up living next to the big container port or the Cross Bronx Expressway or, you know, the South Circular Road in London or who's sleeping on the street in Delhi. It's poorer people and that therefore they are exposed to, you know, much higher levels of pollution. And they're more vulnerable to it because they, you know, are less likely to have access to health care. More likely to have, you know, some other health problem that it may sort of intersect with.

And, you know, the other thing here is sort of a racial divide question, because it's not just economic inequality that is driving this. But, um, there's ah, really terrific new book by a writer named Terry in Washington. It's called a terrible thing to waste about this notion of it's called environmental justice or environmental injustice. This sort of, you know, area of concern. And what she found is that African American neighborhoods, where people are earning 50 to $60,000 a year are exposed to the same level of pollutants as white people who are earning $10,000 a year. So that tells you that this is not just about money. It's also about race and sometimes also immigration,

status, ethnicity. And you know, that sort of comes down to historical questions of, you know, where do sort of polluting companies find it politically Easy toe locate whatever a recycling facility, an incinerator and very often, too often in our history, that has been the neighborhoods of color.

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You talked about China zigzagging. We've been zagging here in the United States to follow a star the last couple of years. Um, you talk about what the E. P. A. Is like under this administration, and it's certainly not the protection agency. They're just trying to dismantle anything that is protective of the environment and human health related to the environment.

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Yeah, I mean, I think there's a lot of things going on there. So obviously, we've seen you know, some really really aggressive environmental protection and health protection rollbacks where the Trump Administration is trying to actually undo these regulations, which, you know, like we were talking about before with the Clean Air Act, these rules that have made America's air cleaner There are studies, literally, the Clean Air Act right. And the regulations that have been implemented under it have saved millions of American lives since 1970 by the way, also trillions of dollars. So you know, we're for sure in danger of going backwards and, you know,

very likely to see dirty or air as thes rules are undone. But I think more than sort of individual rules being changed there. There's a couple of other, you know, really consequential things happening a little bit more beneath the surface. One is a really serious brain drain going on at the E. P. A. Because they're so much, you know, demoralization going on there among longtime staff members who, you know, just see the way things were going and are not being allowed to really properly do their jobs that the p A has, you know, its strength has really been its expertise. There are people working there who are not just health experts,

not just, you know, air quality experts, but sort of technical experts in You know how car engines work and how power plants work so they really can effectively of enforce rules that affect those sectors. And I think to me the most radical thing that's happening right now in the p A around these issues is a new assault on science. Science has really been the pillar of the e p A. And it's been the pillar of the Clean Air Act as well. And we're seeing, you know, I think we've all become pretty used to in recent years, even pre the Trump administration. You know, the dynamic of climate science denial on the right. But now we're also starting to see air pollution science denial. There's a really effort to sort of shoot down some of these enormous sort of gold plated, rock ribbed,

very, very respected studies linking air pollution to all kinds of health problems. Um, and you know, the reason they're doing that is clear because those studies air used to justify regulations that then cost money to industries who have toe comply with them and and kind of clean up their act. And there's a real anti regulatory, you know, zealotry right now in the Trump administration. But they're also doing things like disbanding scientific advisory panels. So the e p. A has always had these sort of advisory board of experts and scientists who give input when they're they're making new regulations or updating regulations. And, you know, they're they're using the language of science actually to attack the science. So one thing they're doing with E scientific advisory panels is they? They said that that they created a rule that said that if you're a scientist and you have received grant money in your career from the e.

P. A. To do research on something which you know, almost all scientists working in the field, we'll have received money like that. You have a conflict of interest, and you can't be on this advisory panel anymore. But if you are from a regulated industry of a coal company or chemical company or a car company, you don't have a conflict of interest, and you are absolutely fine to sit on the board. They're using the language of transparency to try to rule a lot of these big studies on the health effects of pollution out of bounds, their studies that depend on confidential information that's hip protected. And the administration is saying, you know, we want to see the underlying data, which is anonymous ized and can't be released,

their sort of monkeying around with the formula's, where cost benefit Analysis, sir, is calculated to, you know, just if I were not justify a regulation. So to me more than anyone, sort regulatory change is this effort to attack and kind of undermined the science that seems more radical and, you know, potentially more consequential going forward.

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It's, ah, it's mind boggling. And again, the costs of dealing with pollution can be pretty obvious, and the benefits can be somewhat hidden so economically, it looks like, Oh, this is too expensive, we can't do it, but in actuality you get a huge benefit. It's just that the benefit is not related to the actions that you directly took. So if it costs money to put in a scrubber and you save money because a whole bunch of people don't get sick and die you don't see that in the ledger,

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right? And I think that that's such an important part of the political dynamic around, you know, really, probably not just air pollution, but but other kinds of environmental cleanups, too. And it's true, not just in the U. S. But, you know, really everywhere I went, because whenever you talk about environmental regulation, you're very quickly talking about dollars and cents. And what's it gonna cost to clean up? Um,

you know, certainly those are legitimate questions to ask, but we tend to get very focused on the price tag of cleaning up and not very focused on what the benefits will be. And exactly like you said, there's this dynamic that the ones we're gonna have to pay the costs, usually these air our company's, whether it's a a power plant, a utility or it's ah, car company that needs to install, you know, new equipment on their vehicles or whoever the polluter is, they know what it's gonna cost on DDE. That cost is very visible, and oftentimes these air people with the rial political power and voice and a bill ability to influence and have input on the process but the benefits, They're very riel and the science is really strong. You know that there's been a sort of official e p A studies done on the Clean Air Act.

And if they find that the benefits to help and productivity and lives saved in dollar terms, when you monetize that dozens of times greater than the cost. But right exactly like you said, those benefits are very widely spread among sort of, you know, millions of people. And also wait, we don't know that we benefited. Like if I don't have a heart attack tomorrow or I don't lose somebody who I love, you know, I'm not gonna wake up tomorrow and thank a politician you know, 30 years ago, who enacted a regulation that probably I've never heard of and that made the air cleaner than it otherwise would be. It's just an invisible benefit, and we kind of take it for granted, and therefore, the political debate when you're talking about cleaner air and how to get it cleaner tends to focus more on the cost.

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The issue of global warming obviously transcends, like so many different things. But these two subjects air pollution and global warming art, as you said, deeply intertwined. Can you talk to us about how they

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are? Yeah, sure. So I mean, you know, like I said, I do think air pollution is, you know, a really important story. And it's a really important danger, absolutely in its own right. But it is interconnected with climate change because basically they're caused by the same things, and the solutions are the same or they overlap to a large degree. And the way I put it in the book is that thes two problems or both symptoms of this the same thing this unhealthy foundation that we built the modern world on and that's possible fuels. Um, and you know, you can make a lot of progress towards cleaner air,

even with fossil fuels. We have made progress by, you know, tighter regulation and better scrubbers on smokestacks and things like that. But if you really want air that's actually healthy, we are gonna have to move away from fossil fuels and towards clean energy, whether it's wind or solar or other kinds of renewables. So, you know, that sounds really daunting. And and it is don't thing to say, you know, move off fossil fuels. But I guess the other way that look at it and the other way that this kind of dovetails with the climate crisis is that that's something we need to do anyway, right? Get get off of fossil fuels as quickly as possible and onto renewables and cleaner energy in order to keep our climate stable in our planet.

You know, inhabitable. Um so if you know that you've got to do that anyway. But now you're going to get a sort of immediate health Boone from it, which is that you're you're saving the lives and sparing the health of all these people who are currently getting sick and dying from dirty air. Then that sort of seems to me like all the more reason to do this.

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Yeah, absolutely. Um, we we don't have time, But your book has chapters on Poland and the coal situation there, and California and the agricultural pollution and what people have to deal with there. And there's so much good stuff in the book. So and it it's really well written. It was a pleasure to read, which is always nice for me, so I really appreciate that.

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Thanks to you? Yeah, you know, you could I could have almost gone anywhere in the world and written about air pollution because there's not very many places that don't have any of it. But I tried to choose chapters that choose places that would each sort of show us a different facet of the story. So, like you said, you know, Poland's about Cole London's about diesel. Um, San Joaquin Valley, California is about agricultural sources of pollution and and also that dynamic of inequality. And also, you know, I really didn't want to write a book just for people who already know about this for, you know, technical experts.

Air pollution's a daunting subject, right? That puts a big burden on you as a writer to try toe, make it interesting and, you know, show why it matters. And to me, that meant, you know, going kind of up close and telling the stories of not just the people who were affected, but you know, the people who are fighting for change. The people who are, you know, scientists to worse or studying what this does to us and how we can fix it. Politicians and,

you know, political fights, and there's actually a lot of drama there. So, you know, I thought it was a powerful story, and I tried to tell it in a way that you know, would do justice. You've probably heard of gene editing as

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a way to control the spread of malaria or to treat diseases like sickle cell anemia. Jennifer Donna, a pioneer in the field, set off a revolution when she discovered the molecular gene editing tool, Crisper cast nine and Achievement, for which he was awarded the 2018 Kavli Prize In nanoscience. As with every discovery that gives us a glimpse into the unknown, this discovery has unearthed new mysteries and raised questions we never thought to ask before, as part of our partnership with the Catholic Prize Scientific Americans, custom media sat down with doubt to talk about how lessons were. Learning from humble microbes may change the way we handle and think about human disease. End big questions that need to be solved for CRISPR to reach its full potential. But first, what exactly is crisper? Crisper is a genome editing technology. It's a way that scientists can make targeted changes to the D. N.

A in cells or organisms to control the genetics of biology in ways that our transformative down and her colleagues were studying bacteria that used crisper as an immune system. Because crisper can target specific DNA sequences, it protects the bacteria from infection by viruses. Of course, that raises the question of whether crisper could eradicate viruses in our bodies because viruses having a remarkable ability to adapt and evolve resistance to targeting mechanism such as the one used by crisper cast, I think that is not too likely. On the other hand, do I think that there may be ways to target bacteria that are infectious agents and people? Absolutely. I think that's one of the four friends of the field. Down and her colleagues are also sequencing microbial genomes to see what other secrets these organisms hold. Because of the inability of scientists to culture most microbes in a laboratory setting, we know only a very small fraction of those kinds of organisms. So many scientists are studying microbes in the environment by sequencing their DNA and piecing together information about their lifestyles and their community partners and their environmental niches. By looking at their genomes, these studies have revealed that different bacteria have different kinds of crisp air systems,

some of which may even be better than what we're using now. Take, for example, castes X CASS Sex is a fun kind of newer generation of the crisper cast type of enzyme, where it's using an orange, a guided mechanism so it can be programmed to find and cut DNA, just like CASS nine. But it's a lot smaller, and it looks completely different in terms of its molecular shape. So we think that for those reasons, it may be easier to get it into cells for delivery, as well as to ensure that it does the kind of accurate editing that will be necessary, certainly, for clinical use. Aside from treating genetic diseases in the clinic, where else will crisper make its mark?

I think over the next decade or so, we'll see tremendous advances also in agriculture brought about by gene editing, and I think the opportunity to produce plants that have protection from climate change from pests that potentially have higher nutritional value. I think these are all the kinds of things that will be possible going forward, and that's something that I think we'll ultimately, at least in the short term, have broader global impact than any of the biomedical uses. In addition to this broad spectrum of applications, Crisper gives users thehe bility to redirect evolution. This raises ethical concerns within the scientific community. It's a kind of an awesome thing to think about the power to control the evolution of our species. That's something that in the not too distant past would have been unimaginable because we had no idea that there would be a technology that would allow that kind of manipulation of D. N A. But now that it's here, I think it engenders, ah,

time when we have to be very thoughtful and transparent about how this technology will be utilized in the future. How does it affect the inequalities that we see across society? How does it affect people's decisions about reproduction and genetic disease? How do we even define genetic disease? What do we consider to be health versus disease half ways before any of that happens, a collaborative effort will be needed to address some of the controversial issues raised by crisper. I'd like to see a lot more outreach and opportunities for public interaction with scientists to explore not only the fundamentals of the technology but also the broader implications of gene editing. This podcast was made possible through the support of the capital price. The Cabinet Prize recognizes scientists for pioneering advances in the fields of astrophysics, nanoscience and neuroscience. Capital Prize is a partnership between the Norwegian Academy of Science and Letters, the Norwegian Ministry of Education and Research and the US based Kavli Foundation. Jennifer Donna is an H M M. My investigator and professor of molecular and cell biology at the University of California, Berkeley. Don't miss the announcement for the next Kavli Prize Laureates on May 27th 2020.

That's it for this episode. Get your science news at our website www dot scientificamerican dot com, where you can find at least 30 stories in our archives about crisper and gene editing and follow us on Twitter. We'll get a tweet whenever a new item hits the Web site. Our Twitter name is at Siam for Scientific American Science talk. I'm Steve Mercy.

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