Air Date: April 10, 1998

SEGMENTS

The Thirst for Safe Water: Part 2 - Water Quality and Disinfection / Daniel Grossman

Before reaching our homes, most tap water has gone through treatment plants where it is filtered and disinfected. The process is designed to make the water safe. But, research shows that the most common way to treat water adds chemicals that can get turned into cancer-causing agents. The Environmental Protection Agency is taking steps to reduce this danger, but some health experts say the agency isn't doing enough. Daniel Grossman has the second in our series, "The Thirst for Safe Water." (09:45)

Pharmaceuticals in Aqua

Common pharmaceuticals including antibiotics, antiseptics, beta-blockers, and cholesterol-lowering drugs, have been showing up in lakes and rivers, according to new research done in Europe. The drugs don't appear to be coming from manufacturing plants because some were found in the surface water of nations where the drugs are not produced. So, the studies' authors conclude that people and farm animals are passing the drugs through their urine into the watershed. Steve Curwood spoke with Janet Raloff (RALL-off) who is a senior editor at the magazine Science News. (06:10)

Salmonella Songbirds / Nina Keck

If you're a bird lover and have feeders in your yard, you may have noticed some sick or sluggish birds on the perch. Over the past several months, the bacterial infection salmonella, the same disease sometimes found in poultry, has afflicted many flocks of songbirds across New England and parts of the Midwest. As Vermont Public Radio's Nina (Ny-nah) Keck reports, backyard bird enthusiasts can help to control the epidemic. (06:10)

The Living on Earth Almanac

This week, facts about...Squirrels (01:30)

New Ozone Hole Findings

Most of us associate increasing greenhouse gas emissions with climate change. But a group of scientists writing in the journal Nature say greenhouse gases are affecting the earth's protective stratospheric ozone layer as well. Lead author Drew Shindell (shin-DELL) is a scientist at the NASA Goddard Institute for Space Studies. He told Steve Curwood that thanks to rising emissions of carbon dioxide and other climate-changing gases, the ozone layer will stay depleted longer than previously anticipated. (03:35)

Plants & Ozone / Mary Losure

The release of carbon dioxide into the atmosphere does more than affect the temperature of the planet. It's also an important nutrient for plants. Produce growers have known for decades that hothouse crops do better at enhanced CO2 levels. But scientists are still trying to learn how plants will react to increased CO2 in the atmosphere. And as Minnesota Public Radio's Mary Losure reports, their research could also shed new light on how the entire planet might respond to climate changes in the future. (06:25)

Chile Assists Sea Lions / Bob Carty

Producer Bob Carty reports from the Pacific coast of Chile where El Niño has had a devastating impact on some well established marine wildlife. Marine biologists there say they're now learning to prepare for what other changes to marine life the odd weather may be bringing their way. (11:50)

Listener Letters

Views from our audience on declining salmon and political will, low flows and darning thread. (02:20)

Show Credits and Funders

Show Transcript

HOST: Steve Curwood
REPORTERS: Daniel Grossman, Nina Keck, Mary Losure, Bob Carty
GUESTS: Janet Raloff, Drew Shindell

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CURWOOD: From National Public Radio, this is Living on Earth.

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CURWOOD: I'm Steve Curwood. (Theme music intro)

CURWOOD: From National Public Radio, this is Living on Earth.

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CURWOOD: I'm Steve Curwood. Most Americans drink water that's been treated with chlorine. Chlorination kills harmful bacteria, but it also raises the risk of other health threats most notably miscarriages and cancer.

CANTOR: People drinking this type of water thirty or forty or more years have maybe a one and a half to two fold risk of bladder cancer. And this translates to maybe ten percent of all the bladder cancers in the country.

CURWOOD: Also, spring is in the air, the bird is on the wing. But this year may songbirds are spreading salmonella along the way.

KIMBERLY: We're getting reports from 13 states in the Midwest and East, and this all was occurring at about the same time. And they were coming from multiple locations across these states.

CURWOOD: This week on Living on Earth, but first, this news.

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The Thirst for Safe Water: Part 2 - Water Quality and Disinfection

CURWOOD: This is Living on Earth, I'm Steve Curwood. Our bodies contain about 60 percent water, and to stay healthy, we need to drink about two quarts of water every day. Most of us assume that the tap water we get from our municipal supplies is okay. Before reaching us, most tap water has gone through treatment plants where it is filtered and disinfected. The process is designed to make the water safe. But, research shows that the most common way to treat water adds chemicals that can get turned into cancer-causing agents. The Environmental Protection Agency is taking steps to reduce this danger, but some say the agency isn't doing enough. Daniel Grossman has the second in our series, "The Thirst for Safe Water."

(Sounds of birds cawing)

GROSSMAN: The drinking water plant for Cambridge, Massachusetts is a low-slung brick building on the shores of Fresh Pond. Whatever the water’s quality when this reservoir was named, its not so fresh now. And it needs a lot of cleaning before it can be consumed.

MACDONALD: Could we get a filter backwash?

GROSSMAN Inside, the sprawling complex the city’s water quality chief, Timothy MacDonald, is inspecting the plant’s filters.

(Sounds of a valve opening and water spilling out)

GROSSMAN: A few steps away, Mr. MacDonald enters a room with three huge plastic tanks.

MACDONALD: This is where we feed the chlorine chemicals to do the disinfection in the water treatment plant. The chemical we use is sodium hypochlorite. It is a stronger form of the same thing you use at home in your laundry for bleach.

GROSSMAN: Timothy MacDonald says the chlorine compound plays a critical role.

MACDONALD: There are organisms in the water. bacteria, protozoa and other organisms that are harmful to our health. And we need to rid the water of those harmful organisms.

(Sound of a closing door inside of the plant).

GROSSMAN: The invention of disinfection at the turn of the century was largely responsible for ending epidemics of deadly diseases like cholera, that ravaged American cities.

OZONOFF: The purification of drinking water, disinfection of drinking water with chlorination is one of the great public health triumphs in this century.

GROSSMAN: But David Ozonoff, Chair of Boston University’s School of Public Health, says that like other powerful technologies, this one has a down side.

OZONOFF: And as it turns out, natural waters have lots of other things in them--natural products--that can react with the chlorine, and produce a whole suite of other chemicals. And it turns out that some of those chemicals that are produced inadvertently by chlorinating drinking water can also be harmful to human beings.

GROSSMAN: They’re called disinfection byproducts. Researchers have discovered that dozens of such chemicals are formed by water treatment. The most common are called trihalomethanes. They’re molecules created when carbon and hydrogen from decayed plant matter and other naturally occurring elements, combine with chlorine. It's long been known that some trihalomethanes cause cancer in laboratory animals. And recently, researchers have found links to cancer in humans as well. Ken Cantor, a researcher at the National Cancer Institute, headed a study comparing people who drank unchlorinated and chlorinated water from lakes and streams in Iowa. The results were sobering.

CANTOR: People drinking this type of water for thirty or forty or more years have maybe a one-and-a-half to two-fold risk of bladder cancer. And this translates to maybe ten percent of the bladder cancers in the United States. We’re talking in the realm of 4,000 to 4,500 new cases of bladder cancer a year.

GROSSMAN: Doctor Cantor says bladder cancer is fatal about 20 percent of the time. Other researchers have reported similar results. And some scientists have linked cancer of the rectum and colon to chlorinated water. One controversial study by a respected researcher indicated that about one percent of all the country’s cancers are linked to disinfection byproducts consumed in tap water. And there’s more bad news. Research has tied disinfection byproducts to problems such as birth defects, low birth weight and most recently, miscarriage. Doctor Shanna Swan of California’s Department of Health Services heads a team that recently published a study on disinfection byproducts in the journal Epidemiology.

SWAN: Women who drank at least five glasses of tap water a day that had seventy-five parts per billion of trihalomethanes or more had a nearly doubled rate of miscarriage compared to women who either drank less water or water with less trihalomethane in it.

GROSSMAN : Seventy-five parts per billion is significantly lower than the level which the Environmental Protection Agency considers safe. But not everyone is convinced of the danger of disinfection byproducts. Fred Hauchmann is a top official at the EPA’s Health and Environmental Effects Research laboratory. He has doubts about the evidence linking the chemicals to reproductive problems and cancer.

HAUCHMANN: While there is some indication that there may be a slight association between exposure to disinfection byproducts and these endpoints, for the most part the data are still inconclusive with respect to causality. And you really cannot draw a causal association between exposure and effect.

GROSSMAN: The dispute comes down to the level of proof. Epidemiological studies like Shanna Swan’s have shown a clear association between chlorination byproducts and cancer and birth defects. But no one has been able to demonstrate that the substances cause health problems in humans. For many scientists, though, the case against these disinfection byproducts is convincing.

OZONOFF: I don’t know what kind of evidence people who say that would have to have.

GROSSMAN: Boston University Professor David Ozonoff.

OZONOFF: There are many more studies now showing that there’s a causal relationship between disinfection byproducts and cancer than there was in 1949 when we showed that asbestos caused lung cancer, and was generally accepted by the medical community.

(Sound of a faucet opening and water coming out into a glass)

GROSSMAN: Virtually every American drinks water that's disinfected with chlorine every day . And the debate about the health effects of that process is heating up because the EPA is slated to tighten its safety rules this fall. The agency is expected to cut the current trihalomethane standard of 100 parts per billion to 80 parts per billion, and to set standards for another common class of byproducts as well. But Professor David Ozonoff says the agency should go even further.

OZONOFF: If this were a chemical that were leaked into the drinking water supply, contaminated by a barrel back in the back forty somewhere, it would never be set at a hundred, it would be set at 5 or less.

GROSSMAN: But some caution that the concern about the risks of chlorination should not obscure the very real and much larger benefits. Jack Sullivan is a top official at the American Water Works Association.

SULLIVAN: There must be a backstop. You cannot do anything that is going to increase the microbial risk. We must at all costs take what steps are necessary to prevent the microbial disease and do everything we can about balancing the tradeoffs associated with the disinfection byproduct risks.

GROSSMAN: Many experts though say the choices are not so stark: that we don’t have to choose between cancer on the one hand and germs on the other. The city of Cambridge has begun to reduce the level of disinfection byproducts in its water without increasing the risks of microbial contamination. Water quality supervisor Timothy MacDonald says a decade ago byproduct levels at his plant were among the worst in the country.

MACDONALD: The problem was that this plant was putting out elevated THM levels that ultimately I guess got up to 320 parts per billion.

GROSSMAN: Trihalomethane levels in Cambridge were three times the standard in 1989. Its 65 year old plant was dilapidated and poorly run.

MACDONALD: The filter media was in poor shape, the backwash system was not effective.

GROSSMAN: A year and only about a million dollars in changes later, trihalomethane levels had been cut to half the federal standard without violating disinfection requirements.

(Sound of Cambridge plant)

GROSSMAN: Of course simple changes won’t work everywhere. And many experts are calling for dramatic cuts in byproduct levels which would require a completely different approach like using the alternative disinfectant ozone, a gas widely used in Europe. Ozone also creates disinfection byproducts, but so far they don’t appear to be harmful. Better filters with activated carbon which cut down on organic matter can also help reduce byproducts. Of course all of these technologies cost a lot of money, and communities and governments need to decide whether the benefits are worth the costs. Here in Cambridge they’ve made the decision. Next year the city is breaking ground on a new fifty million dollar treatment plant using both activated carbon and ozone. It will be the largest public works project in the city’s history. For Living on Earth, this is Daniel Grossman.

CURWOOD: Next month, our series "The Thirst for Safe Water" continues with a look at how farm chemicals contaminate drinking water supplies in the Midwest.

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Pharmaceuticals in Aqua

CURWOOD: Common pharmaceuticals, including antibiotics, antiseptics, beta blockers, and cholesterol-lowering drugs, have been showing up in lakes and rivers, according to new research done in Europe. The drugs don't appear to be coming from manufacturing plants, because some were found in the surface water of nations where the drugs are not produced. So, the study's authors conclude that people and farm animals are passing the drugs through their urine into the watershed. In some cases, the absorption rate of a drug is as low as 10%; the rest is excreted. Janet Raloff is a senior editor at Science News. She says she was surprised by what she discovered covering this story.

RALOFF: It sort of blew me away. (Laughs) I wasn't expecting it at all. I guess if I'd really thought about it, maybe I should have expected they might be in there, and that's in fact one of the reactions I get from some of the scientists I talk to. That gee, I hadn't thought about it, but it must have been going somewhere. I guess it makes perfect sense that it ends up there. What surprised me even more is that some people who one would think have been charged with making sure the environment stays relatively clean haven't been focusing on this issue at all. There are no measurements made of our water. They're being made now, periodically in various places in Europe, and wherever they look they find this stuff. The more they look, the more they find.

CURWOOD: Now, is our government, is the US Government at all interested in funding this line of research in the wake of what's being found in Europe?

RALOFF: Well, let's say I haven't found people who are interested in funding it yet. The philosophy seems to be that EPA doesn't have responsibility for looking for these things in the United States. That would be the Food and Drug Administration. And that EPA doesn't have really enough money to be doing what it's supposed to be doing, which is cleaning up standard pollutants, so it's not supposed to be out there. Congress has told that it's not supposed to be out there looking for new problems. The feeling I got was that the spirit was willing; the funding just wasn't there to go ahead and do it.

CURWOOD: What's a concern here? Why does it matter that all these pharmaceuticals are getting into rivers and streams?

RALOFF: Nobody's quite sure exactly what they should be most concerned about if anything. The general feeling is that what probably would present the first line of risk would be the antibiotics. If small concentrations of these antibiotics are showing up all over the place, they may end up encouraging antibiotic-resistant, the buildup of bacteria that can live in the presence of these antibiotics. Then, when they encounter them in the human body, they just sort of laugh at the antibiotics and people stay sick. Whether it's a legitimate risk, nobody really knows. Nobody's really tested at this point.

CURWOOD: Is there anything else to be worried about regarding these pharmaceuticals in water?

RALOFF: Well, people are concerned about the estrogen-mimicking chemicals. There is some concern that it could affect fish and other small biota. For example, bacteria, little crustaceans, the bottoms of lakes and streams. But nobody's quite sure. They have found concentrations recently at levels that are sufficient to feminize fish, so clearly something very strange is going on. And it can happen at the level at which these things are showing up in certain water supplies.

CURWOOD: Janet Raloff, what about places where treated wastewater gets into the drinking water supply? People who get water from rivers, that sort of thing. Is anyone testing for the presence of pharmaceuticals there?

RALOFF: They're not testing in the United States. They are testing in a few places sporadically in Germany, in particular Berlin and Wiesbaden. The levels they're finding are very small, generally lower than what you're finding in surface waters such as streams. Maybe in the parts per billion range, more likely in the parts per trillion range. Nobody has any idea what this means. The levels are so much lower than you would be exposed to if you were taking a drug for a therapeutic purpose. But remember, these are in people who aren't sick, and they may be exposed their entire life every day. So it's a really different situation and people haven't a clue what the long-term implications might be.

CURWOOD: Now, one reason we're finding it is what? Because of new technology?

RALOFF: That's part of it. That's right; you have to have some very sensitive analytical techniques. And you have to have for the most part crackerjack chemists who are focusing on this. The other thing is, you have to know what you're looking for. It's not like you just analyze some water and you see 50 or 100 different chemicals in it. In order to find and understand what those chemicals are, you have to actually be looking for many of these things specifically. People tended to find this when they did initially because they were looking for chemicals that were similar in structure to these drugs. They were actually for the most part pesticides. And when they found something that looked like the pesticide they wanted but was a little bit wrong, they weren't quite sure why but they would just look a little closer and see if the analytical techniques were off a bit. It turned out they weren't, and what they were finding was a structure that was off a little bit. And the more they looked, the more they realized these things were in fact drugs, and not the pesticides they'd initially been focusing on.

CURWOOD: Is this a solvable problem? Do we have the technology available now that could take pharmaceuticals out of water?

RALOFF: I don't think anyone's really looking at it. But there's no reason people shouldn't be able to. It's just a matter of deciding that's what you want to do. Presently, wastewater treatment plants aren't designed to take them out because people hadn't really thought about whether they might be there. If they worked on it, I'm sure they could. The people I talked to suggest it's doable. It's just a matter of sort of setting your mind that that's the priority for what these treatment plants are supposed to do.

CURWOOD: Janet Raloff is a senior editor at Science News. Thanks for joining us.

RALOFF: Thank you.

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CURWOOD: For tapes and transcripts of this program please call 800-218-9988. That's 800-218-9988 for tapes and transcripts. Just ahead: an old disease poses a new threat to songbirds. Stay tuned to Living on Earth.

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Salmonella Songbirds

CURWOOD: It's Living on Earth. I'm Steve Curwood. If you're a bird lover and have feeders in your yard, you may have noticed some sick or sluggish birds on the perch. Over the past several months the bacterial infection salmonella, the same disease sometimes found in poultry, has afflicted many flocks of songbirds across New England and parts of the Midwest. As Vermont Public Radio's Nina Keck reports, backyard bird enthusiasts can help control the epidemic.

(Birdsong)

KECK: At the Raptor Center in Woodstock, Vermont, the sounds of exotic eagles, owls, and hawks, mingle with the quieter songs with chickadees. Michael Cox, director of the center, says his office has been flooded with calls concerning the salmonella outbreak. Mr. Cox points to the chickadees at a nearby feeder and says unlike these healthy birds, sick birds are lethargic and have puffed up feathers.

COX: These birds affected by salmonella have also been observed eating a lot of snow. We can't really explain that. Salmonella causes a substance in the mouth, a cheesy substance that inhibits their esophagus and inhibits their trachea, so that is part of the reason that they are dying.

KECK: Salmonella is a bacteria that's common among many species. In humans it causes vomiting, diarrhea, and high fever, but it is treatable. In songbirds the disease is often deadly. Over the past several months, hundreds if not thousands of songbirds throughout New England and parts of the Midwest have fallen victim. Solid numbers are hard to come by because not everyone reports or even notices ill birds. In Vermont, pine and evening grosbeaks, as well as redpolls have been most affected. Other states have reported deaths among red crossbills, pine siskins, and goldfinches. The disease is spread in the birds' droppings, and Michael Cox says bird watchers can help break the cycle of infection.

COX: To help stop it, we are recommending that if you have had birds affected by the bacteria, to take the feeders down, clean the feeders with a 10% bleach solution, and leave those feeders down. Leave them vacant for 1 to 2 weeks, and that will get the flocks of songbirds to disperse. Once that has happened, then the feeders can be put back up. Discarded seeds, spilled seed around the feeders, is best -- that can be, should be raked up and should be disposed of.

KECK: The bacteria rarely spreads to people and pets, but it is possible. So wear gloves when handling feeders and wash hands thoroughly afterwards. Don't wash feeders in the kitchen sink, and don't let pets eat or play with any dead birds in the yard. It is common for songbirds to become infected from time to time, but this outbreak is unusually widespread. Dr. Kimberly Miller is a wildlife disease specialist with the United States Geological Survey in Madison, Wisconsin.

MILLER: In this instance, we're getting reports from 13 states in the Midwest and East, and this all was occurring at about the same time. And the reports were coming in not just from one bird feeder or one small town here and there; they were coming from multiple locations across these states.

KECK: Dr. Miller says experts don't know why the outbreak is so widespread, and it's also unclear why certain species are more affected than others. There are over 2,000 strains of salmonella, and backyard feeders aren't the only place that birds become infected. Standing water and regions with sewer or agricultural runoff can also harbor the bacteria. Neither Mr. Cox nor Dr. Miller expect this year's die-off to have a long-lasting impact on the songbird population, but it is difficult to watch. The Raptor Center's Michael Cox says in Vermont, nature is already helping to slow the salmonella outbreak. Over the past few weeks most of the healthy redpulls in the state have begun heading north for the summer, dispersing the population and slowing the cycle of infection. For Living on Earth, I'm Nina Keck in Vermont.

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CURWOOD: It's NPR's Living on Earth. I'm Steve Curwood.

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ANNOUNCER: Funding for Living on Earth comes from the World Media Foundation Environmental Information Fund. Major contributors include the Ford Foundation for reporting on environment and development issues; the William and Flora Hewlett Foundation for reporting on western issues; the Pew Charitable Trusts for reporting on threats to the world's marine environment: www.pewtrusts.com; and Jennifer and Ted Stanley.

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NPR ANNOUNCER: This is NPR, National Public Radio. CURWOOD: New evidence that global warming may be harming the protective stratospheric ozone layer. That's coming up in just a minute; stay tuned to Living on Earth.

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SECOND HALF HOUR

ANNOUNCER: Funding for Living on Earth comes from the World Media Foundation Environmental Information Fund. Major contributors include Stonyfield Farm Yogurt, dedicated to your health and the health of the planet; and Church and White, a tradition of environmental responsibility: the makers of Arm and Hammer Baking Soda, the standard of purity.

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CURWOOD: It's Living on Earth. I'm Steve Curwood

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The Living on Earth Almanac

CURWOOD: This is the time of year when many animals emerge from their cozy winter nests. One of the most ubiquitous is the squirrel. Its name comes from the Greek word skiouros, meaning "little shadow tail." Now, the squirrel's adapted to just about every region in the world, and the bushy rodents have their fans. The Squirrel Lover's Club was launched about 3 years ago, and at least 600 people have signed on so far. But squirrels also have plenty of antagonists. I mean, just ask any home dweller who has lost sleep listening to their scratchings inside the walls. Or talk to some Connecticut rail riders. Back in 1995, a squirrel jumped on the electrical lines that supply power to the trains, short-circuited the system, and left some 47,000 commuters stranded for several hours. And 4 years ago another squirrel danced on the power lines. This time it led to a temporary shutdown of the NASDAQ stock-trading network. And for this week, that's the Living on Earth Almanac.

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New Ozone Hole Findings

CURWOOD: Most of us associate increasing greenhouse gas emissions with climate change, but a group of scientists writing in the journal Nature say greenhouse gases are affecting the Earth's protective stratospheric ozone layer as well. Lead author Drew Shindell is a scientist at the NASA Goddard Institute for Space Studies. He says that thanks to rising emissions of carbon dioxide and other climate-changing gases, the ozone layer will stay depleted longer than previously anticipated.

SHINDELL: We expect that in the Antarctic, we will not see a great change. And that's mostly because the ozone depletion is already so thorough. In the Arctic, however, where the depletion hasn't been as great, we do see the ozone loss getting distinctly worse, and reaching its worst levels in about 15 years.

CURWOOD: Okay, we need some help with the science here. Why is this happening? How can greenhouse gases like carbon dioxide affect the ozone layer?

SHINDELL: Well, the chemistry that depletes ozone in the polar regions is extremely sensitive to temperature. It only happens in the polar regions because that's the only part of the stratosphere where it gets cold enough. So what the greenhouse gases do is warm the atmosphere down low near the Earth's surface, and that's what we commonly call global warming. But up high they lead to a cooling; it's the opposite effect. That makes the chlorine that's up there be more effective at depleting ozone.

CURWOOD: Now, your computer model predicts that greenhouse gases and climate change make ozone depletion worse. Is there an effect going the other way? Does ozone depletion make climate change worse?

SHINDELL: In general, the depletion of the ozone layer acts to reduce global warming, because ozone is itself a greenhouse gas. Now, in the future what we expect is that with the limitations on emissions of CFCs, the ozone layer should recover. And while that's certainly a good thing, since it will help to protect the Earth from receiving too much ultraviolet radiation, that should actually increase global warming slightly.

CURWOOD: In other words, once we started fooling with the system by adding chlorine that depletes ozone, by adding greenhouse gases, we've kind of gotten ourselves into something that it's pretty complicated to get out of, huh?

SHINDELL: Well, we've addressed the problem of ozone depletion to some extent. But the problem of ozone depletion has actually made the problem of global warming look not quite as bad as it might have looked otherwise. So once ozone depletion goes away, global warming begins to look as bad as it really is, and that's an issue where we have a long way to go before we've addressed that satisfactorily.

CURWOOD: What kind of basic conclusions can you make from your findings here about the whole scope, the whole effect of greenhouse gas emissions on the planet?

SHINDELL: Well, I would have to say that greenhouse gas emissions probably have lots of effects on the planet that we haven't even thought about. Maybe that's one of the most important lessons from this research: is that greenhouse gases don't just cause global warming, but it's an enormous change to the planet. And it has the potential to affect all sorts of things; it has the potential now, we see, to affect the ozone layer, which is not something that we had been thinking about before. Maybe it has the potential to affect lots of other things.

CURWOOD: Drew Shindell is an atmospheric scientist at the NASA Goddard Institute for Space Studies and Center for Climate Systems Research at Columbia University. Thanks for joining us today.

SHINDELL: Thank you.

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Plants & Ozone

CURWOOD: The release of carbon dioxide into the atmosphere does more than affect the temperature of the planet. It's also an important nutrient for plants. Produce growers have known for decades that hothouse crops do better at enhanced CO2 levels. But scientists are still trying to learn how plants will react to increased CO2 in the atmosphere. Their research could also shed new light on how the entire planet will respond to climate changes in the future. Minnesota Public Radio's Mary Losure has our report.

LOSURE: The greenhouses at Len Bush Roses in Plymouth, Minnesota, produce 5 and a half million roses every year, near-perfect flowers cut each morning and evening. At intervals throughout the 7 acres of greenhouses, hoses blow pure carbon dioxide into the warm air.

EDSEL: This is the actual injection tube, and you can hear it's injecting right now.

LOSURE: CO2 levels inside this greenhouse are boosted to as high as 1,000 parts per million, nearly 3 times what's found in the air outside. Greenhouse manager Pat Etzel says the effect on the roses is clear.

ETZEL: We can see enhancements anywhere from 10 to 40 to 50% increase in overall growth. And that's translated into longer stems, thicker diameter stems, larger leaves, larger flowers.

LOSURE: This is no surprise. Scientists have known for a long time that carbon dioxide, like water, is essential to plant growth. And when they get more of it, many plants grow better. But researchers are uncertain how plants outside greenhouses and laboratories respond when CO2 levels increase. It's an important question, because atmospheric CO2 levels have climbed 25% since the beginning of the Industrial Revolution. Scientists expect that level to double some time in the next century. Researchers are getting some answers by growing plants with extra CO2 at open air sites around the country. George Hendrey of the Brookhaven National Laboratory is the coordinator of the studies.

HENDREY: We've worked with cotton, with wheat, with pine trees. We're now doing sorghum in large agricultural experiments out in Arizona. And all of these plants that we expose to elevated carbon dioxide show a very dramatic response to elevated carbon dioxide.

LOSURE: George Hendrey says the experiments prove photosynthesis, the process by which plants convert carbon dioxide to food, can increase dramatically under high CO2 conditions, and crop yields can be boosted as much as 30%. And he says those aren't the only benefits.

HENDRY: We see photosynthesis increasing without an equivalent increase in the amount of water use. You get a greater amount of crop production for equal amounts of water used.

LOSURE: Results such as these are often cited by those opposed to curbing fossil fuel use: the largest human source of carbon dioxide. A newsletter funded by the Western Fuels Association, a group of electric utilities, calls CO2 "the best plant food since Miracle Gro." The Western Fuels Association is one of the nation's largest coal customers. But others are more cautious. Harvard Biologist Fakhri Bazazz has been studying the effects of high CO2 since the 1970s.

BAZAZZ: Some plants, agricultural crops in developed countries, will probably do well. But there's the rest of the world.

LOSURE: Professor Bazazz says while increased CO2 may benefit well-fertilized, evenly-spaced crops in the industrialized world, it may not be good news for crops grown in developing countries where farmers can't afford lots of fertilizer and herbicides. And he says no one knows exactly how tropical forests, grasslands, and other ecosystems will fare. For example, higher CO2 levels may change the flowering and fruiting time of plants.

BAZAZZ: If that is changed by high CO2 environments such that you decouple the insects from their food, from their flowers, then the plants will fail completely because they, in a tropical forest particularly, depend solely on these very specific insects.

LOSURE: In natural ecosystems, where many kinds of plants compete with one another, Professor Bazazz says higher CO2 could upset the balance of species. Because some plants are able to take advantage of high CO2 better than others, some species may thrive and others may suffer.

BAZAZZ: And I think if we put all of these things together, I really don't think that the picture is as rosy as some of the initial arguments.

LOSURE: Just how ecosystems respond as CO2 levels continue climbing could also have important implications for climate change. George Hendrey of the Brookhaven National Lab says scientific predictions of global climate change are based on the idea that researchers understand where CO2 is going in the atmosphere.

HENDREY: But what we don't have a good idea is how the natural system will behave in the future, decades to a century or 2 centuries in the future. Will natural systems be able to withdraw more CO2 from the atmosphere?

LOSURE: If natural systems like grasslands or forests are revved up by higher CO2 levels and absorb more of the gas, that could slow global climate change. That's why Hendry says it's critical to figure out how ecosystems respond to changes in the composition of the atmosphere. So far, the open air CO2 experiments have been done mainly in managed plots such as crop lands and a pine plantation in North Carolina. But researchers are starting to do the experiments in natural settings, such as a pinion pine juniper grassland in Arizona. And they're making plans to set up a network of carbon dioxide experiments in other ecosystems around the world. For Living on Earth, I'm Mary Losure.

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CURWOOD: Coming up: El Niño and the sea lions of Chile. Stay tuned to Living on Earth.

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Chile Assists Sea Lions

CURWOOD: It's Living on Earth. I'm Steve Curwood. It ain't over till it's over. Even though El Niño of 1997-98 has already set a record in the US with the warmest and wettest January and February in 104 years, the effects of the weather phenomenon are likely to linger until at least June all over the world. The chief of the National Oceanic and Atmospheric Administration, James Baker, recently said El Niño was a window on the future of global warming. He called it a taste of what we might expect if the Earth warms as is now projected. It is a taste that some are finding bitter, as tornadoes in the South and floods in the West have taken lives. In Latin America the Amazon rainforest dried to a crisp and a patch of it the size of Belgium burned up. In Peru fish stocks disappeared and a lake now covers a northern desert. And as Bob Carty reports in Chile, El Niño has had a devastating impact on wildlife.

(Splashing water and children laughing)

CARTY: Halfway down the thin slice of a country called Chile, there's a little cove near the port of San Antonio. The water here is usually so cold you can't dip your toe in. But today, some neighborhood boys are swimming in the warm waves. Around the boys playing in the surf are 3 young sea lions: black and sleek and about the size of large dogs.

(Sea lions barking)

CARTY: They bark and snort and grunt and squeal, and one of them dives toward the shore, where a 5-year-old child is sitting on a rock. The sea lion pops his head up right between the child's legs.

(Splashing, the sea lion grunts, the child screams)

CARTY: The sea lion splashes away, and Manuel Hermosilla tries to calm the child. Sea lions are just curious about people, he explains, especially this sea lion.

HERMOSILLA: [Speaks in Spanish] TRANSLATOR: There he is, Erre- R. He was the first one freed here in the cove, so we didn't give him a number. But the letter R as in rescue. He's a king of the beach and you have to respect that.

CARTY: Manuel Hermosilla is a local businessman and a member of a wildlife rehabilitation group. He explains that unlike seals, sea lions have larger, blunt snouts and visible ears. Adults are enormous, with the males developing a ring of fat around the neck that some say looks like a lion's mane. Manuel Hermosilla says to him, they look like mermaids. It's thanks to Manuel Hermosilla and dozens of volunteers that these sea lions are alive today. Their rescue from the threat of El Niño began three months ago when these beaches reeked of death.

HERMOSILLA: [Speaks in Spanish] TRANSLATOR: There are always some sea lions that die. That's normal. But this year we found 115 sea lions washed up on the beaches near here. They were obviously malnourished. They had no blubber. We either found them dead or they died as we tried to rescue them.

CARTY: In the last 3 months, dead sea lions have been found all along the Pacific coast of South America. In Peru, biologists have counted at least 5,000 dead animals. Tens of thousands more may have died at sea, possibly threatening the sea lion population in this part of the world. Bernardo Reyes, the director of the Institute for Political Ecology, says the cause is clearly the El Niño phenomenon. Normally, a cold ocean current, the Humboldt current, flows from Antarctica up the coast of Chile and Peru. But in an El Niño year, the Humboldt moves further offshore, and the nutrient-rich current sinks beneath a layer of warm El Niño water.

REYES: What happens is that we have a drastic change in water temperature. And when the water warms up, that is a critical change, to change the plankton, which are the little animals that provide the food for fish. So fish starve, or they go further away from the coastal areas looking for food. And therefore, animals that prey on fish: sharks, large mammals like sea lions, like whales, like dolphins, starve.

(Crashing waves)

CARTY: Most of the sea lions that died here were only several months old. At that age they still need their mother's milk and they are inexperienced swimmers. Normally they'd be left on shore while their mothers fished in deeper water, returning to suckle their pups. But this year, the mothers did not return. By the time wildlife workers found the pups, some of them were beyond help. Veterinarian Diego Albareda conducted autopsies on the bodies.

ALBAREDA: In some animals a lot of stones; in one animal we have found 11 or 15 stones.

CARTY: That's not usual for baby --

ALBAREDA: No. In baby animals is not usually. We've seen that they ate the stone because they are hungry.

(A pup cries for food)

CARTY: Hungry like this.

(Crying continues)

CARTY: On the patio of a small nature museum in San Antonio, Jose Luis Brito is trying to feed one of the sea lion survivors. It's a 25-pound bundle of soft brown fur and limpid eyes.

(Crying continues)

BRITO: [Speaks in Spanish] TRANSLATOR: Baby, Baby is the name we gave him. Now he's almost 3 weeks old, but he doesn't suckle. So we have to feed him with a tube directly down to the stomach.

(Scraping sounds)

CARTY: Jose Luis Brito feeds Baby a substitute sea lion mother's milk mixed up in a metal bowl. The cuddly little animal in his arms will eventually grow into a 700-pound, 7-foot-long bull sea lion. Baby is one of 78 young sea lions that have been saved so far. When the pups were abandoned by their mothers, the strongest ones headed from the shore inland. People found them on side streets, in gardens and patios, under cars and trucks. Towns that rely heavily on fishing are not always fond of sea lions, but here hundreds of volunteers helped rescue the pups. At the museum, they pitched in to give medication, to wean the pups from artificial milk to fish, and to help them to swim a few hours a day in a shallow pool. As they grew in size and in their ability to swim and digest whole fish, the pups were returned to sea, and the sea itself is now beginning to return to normal temperatures. Jose Luis Brito maintains that they could have saved more sea lions, if they had been prepared.

BRITO: [Speaks in Spanish] TRANSLATOR: We did what was possible, but the authorities did not respond. Chile has 4,500 kilometers of coastline, and it doesn't yet have a center for the recuperation of marine wildlife.

(Surf and seagulls)

CARTY: Sea lions are not the only victims of this year's El Niño. Ecologist Bernardo Reyes explains that along the coast, people are finding unusual kinds of wildlife and thousands of dead pelicans and cormorants.

REYES: Marine birds feed on fish, and they are dying off. They are migrating, to fuel the migration, they can't migrate too far if they don't have food. So we also have a massive impact on bird population that will also reproduce less. They found some turtles in northern Chile that were not typical of the area, and they didn't know what to do with them because they're never seen in the area. So when the biologists came around to identify them, they discovered that they were Central American turtles, and they are coming, following the warm waters.

(Mingling, many voices and clattering sounds)

CARTY: The wider impact of El Niño can be seen here, in Santiago's fish market, where vendors clean shrimp and clams and mussels. These fish mongers say they have hardly any mackerel this year, and the prices of some shellfish are up 1,000% due to scarcity. Ecologist Bernardo Reyes.

REYES: In the fisheries sector, we expect that this year we are going to have a reduction in fish catch by about a factor of 20%. This is going to have a large impact on employment, because these employ lots of people in the fish meal operation. The recovery process in the fisheries will take at least 2, 3, to 5 years. Most people are concerned with the failures of fisheries this year, and most people are concerned with these unusual weather patterns.

(Music and weather announcer speaking in Spanish)

CARTY: On Santiago television, weather reports are somewhat reminiscent of a dentist's office. The tone is reassuring, the music syrupy. But most people aren't fooled about what could happen next.

(Music and announcer continue)

REYES: We have seen in Santiago in the past 12 months, you know, events I've never seen in my whole life. Raining in November and December, even January. Snowing, you know, in spring, things like that.

CARTY: Juan Carlos Castilla is a marine biologist with the government's Science Research Foundation. He points out that environmental assessments of El Niño tend to only account for negative impacts. As strange as the weather has been in this El Niño year, Castilla insists there are some positive benefits.

CASTILLA: We've been going through, you know, probably 6 years with no water, particularly in central and northern Chile. Chile has water now. All the dams are full, and we will have water for 5 more years--no problem at all. So that's a positive.

CARTY: El Niño may have brought an end to the drought, but environmentalists are not quick to celebrate. In Chile's fast-growing economy, as river beds dried up in recent years urban settlement moved into the lowlands. Now, homes and factories are being washed away by flash floods. And floodwaters are also carrying pesticides and mining wastes down to the sea for the first time in years. For ecologist Bernardo Reyes, there's a lesson here. Reyes contends that Chile's resource extraction economy has left the nation and especially its poor people exposed to the vagaries of unusual weather.

REYES: In the past 10 years we've had the driest spell this century and the warmest spell this century. So, global warming is having a larger impact on phenomena such as El Niño, because we are becoming much more vulnerable when temperatures go from one extreme to the other. We cannot be prepared both for very cold weather and for very hot weather, for very long prolonged drought periods. It's given us a chance to rethink how we're planning the use of our ecosystem.

(Children splashing in water, sea lions barking)

CARTY: Back at the cove near San Antonio, the sea lion named R is playing in the waves. Manuel Hermosilla walks down the beach, where he and his colleagues released 78 sea lions they were able to save this year.

HERMOSILLA: [Speaks in Spanish] TRANSLATOR: This is where we put them back into the sea, when they are healthy enough and can feed themselves. And maybe it was divine intervention. What happened was that the sea lions took over this beach, as if it was the place of their birth. And the first male who was released, R, he became the owner of this cove. And he's very intelligent. Every time we come to release the rehabilitated sea lions, he comes up to smell them and to receive them as part of this group. It's very good.

(Sea lions barking, children laughing and splashing)

CARTY: The El Niño effect is now subsiding in Chile. However, it could be another year before the full impact on the fishery and on the sea lion population is fully understood. Wildlife enthusiasts, like Manuel Hermosilla, say they'll be better prepared the next time an El Niño rises. But he admits that no one knows what the next time will wash up on shore. For Living on Earth, I'm Bob Carty near San Antonio on the Pacific Coast of Chile.

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Listener Letters

CURWOOD: And now it's time to hear from you, our listeners. Our story on salmon restoration in the Pacific Northwest drew a response from Steve Erickson. He hears us on KUOW in Seattle, where he works with conservation groups on salmon issues. Mr. Erickson notes that while the biologists in King County are doing excellent work, ultimately they don't make the important decisions. "I don't know whether to laugh or cry," he writes, "at the suggestion that local county governments would voluntarily take steps necessary to save salmon from extinction. When push comes to shove, the local politicians follow the development money, or simply don't value the natural world sufficiently to protect it."

Livia Shagum, a listener to WHYY in Philadelphia, heard our stories on the perils of low-flush toilets and called to offer this water conservation tip.

SHAGUM: In Israel we have toilets with sort of a dual flush, so you can choose half a tank or a full tank. But in my house, which is older, we have faucets on the tank, and then you can just open it and use as much water as you think is necessary.

CURWOOD: Finally, another WHYY listener, Dorothy Sakaguchi, called with this advice for Ruth Page, who in a recent commentary lamented the death of darning thread, along with other vestiges of the Great Depression.

SAKAGUCHI: Ruth, cheer up! All is not lost. There still is darning thread. If you will go to a little Amish community I bet you'll find some. I can find black or white up here at Lancaster, Pennsylvania. If you need some, I could send some. Please give me a call.

CURWOOD: Please give us a call. We're always interested in what you have to say. Our listener line is 800-218-9988. That's 800-218-9988. Or you can e- mail us at LOE@NPR.ORG. That's LOE@NPR.ORG. And for this week, that's Living on Earth.

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CURWOOD: Living on Earth is produced by the World Media Foundation in cooperation with Harvard University. Our staff includes George Homsy, Jesse Wegman, Terry FitzPatrick, Daniel Grossman, and Liz Lempert, along with Peter Christenson, Roberta deAvila, Peter Shaw, and Julia Madeson. Eileen Bolinsky is our technical director. Peter Thomson heads our Western Bureau. Chris Ballman is the senior producer. We had help from Jeremy Jurgens, Vanessa Melendez, and Miriam Landman. Michael Aharon composed the theme. I'm Steve Curwood, executive producer. Thanks for listening.

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ANNOUNCER: Funding for Living on Earth comes from the World Media Foundation Environmental Information Fund. Major contributors include the W.K. Kellogg Foundation for coverage of sustainable agriculture; the Geraldine R. Dodge Foundation; the National Science Foundation for coverage of science in the environment; the David and Lucile Packard Foundation; the W. Alton Jones Foundation, promoting new economic approaches to advance environmental protection and human prosperity; www.wajones.org.

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