Air Date: May 17, 1996
Breastfeeding Baby: A Modern Dilemma/ Andrea DeLeon
Nature's most perfect food, breast milk, helps growing infants develop resilient immune systems. But along with the welcome antibodies are the persistent toxins she may have ingested in her lifetime which are stored in mother's fatty tissue and are also passed on to baby. As the mother of a newborn, reporter Andrea DeLeon recently grappled with the dilemma of balancing the health risks against the benefits of breastfeeding and shares her findings with us. (13:05)
Throwing Away the Spray: Organic Gardening Tips for Listeners
Millions of Americans enjoy their most direct contact with the natural world through the increasingly popular activity of gardening. With this in mind, the "Green Garden Spot" will become a semi-regular feature of Living on Earth with tips from Evelyn Tully Costa. Tully-Costa is a public radio producer, and a professional garden designer. Steve Curwood talks with Evelyn about why she got involved in organic gardening, and gets practical suggestions on how others can get started. (07:08)
The Living on Earth Almanac
Facts about... the Mississippi River. (01:15)
Strange Death: Disease and Manatees
Steve Curwood speaks with marine mammologist Nina Young of the Center for Marine Conservation in Washington, D.C. about a recent wave of unexplained manatee deaths that has so far claimed 250 victims. With only 26,000 of the sea cows surviving today, marine conservationists are concerned by the loss of so many animals, many of which are adult females. Post-mortem necropsies are finding blood hemorrhages in the lungs, lesions, even muscular and neurological problems. (04:08)
Up to Their Ears in Undersea Noise/ Dan Grossman
How do different animals hear? How does infrasonic versus ultrasonic sound detection affect a marine animal's behavior? What if any impact do ships propellers or military underwater tests have on ocean life? Dan Grossman looks at some of these questions in this sound-rich report exploring some of the scientific research being conducted into undersea noise. (15:02)
Meals for Microbes/ Cheryl Colopy
In many places, leaking fuel from gas station underground fuel storage tanks is an environmental hazard threatening groundwater. In California, where clean-up has been a priority, use of a new cleaning method is starting to move ahead and it's called bio-remediation. In bioremediation, microbes already existing in the soil go to work on the fuel so people don't have to. Cheryl Colopy reports on the technique and if it will actually do the job. (05:55)
Copyright c 1996 by World Media Foundation. No portion of this transcript may be copied, sold, or transmitted without the written authority of World Media Foundation.
HOST: Steve Curwood
NEWSCASTER: Jan Nunley
REPORTERS: Michael Lawton, Kelly Griffin, Andrea DeLeon, Dan Grossman, Cheryl Colopy
GUESTS: Evelyn Tully Costa, Nina Young
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CURWOOD: From National Public Radio, this is Living on Earth.
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CURWOOD: I'm Steve Curwood.
Nature designed the perfect food for babies: mother's milk. It provides the best nutrition with crucial antibodies and a deeply loving experience. But it also concentrates dangerous pollutants like PCBs and dioxins.
PAGAN: Breast fed babies are taking in dioxin at a level that is 10 to 100 times more than an adult is getting.
CURWOOD: We'll hear a personal account of the breastfeeding dilemma from a nursing mother. Also, it's time to get out in a garden. We'll get some advice from a gardener who switched over to the organic way.
COSTA: So, I chucked the space suit and then I began to ignore all the advice that said kill this, spray that, and then run for cover.
CURWOOD: That and more this week on Living on Earth, right after this news.
NUNLEY: From Living on Earth, I'm Jan Nunley. The US Department of Energy plans to import about 20 tons of nuclear waste from research reactors in 41 countries. The DOE says the move is part of an effort to prevent the weapons grade material from being used for bombs. The bulk of the material will go to the Savannah River site in South Carolina for indefinite storage. South Carolina officials have already lost several lawsuits to block previous shipments, but they say they are reviewing their legal options. The Natural Resources Defense Council says the DOE's waste buyout is necessary to wean the world off the commercial use of nuclear weapons.
House Republicans say they want more flexible and innovative environmental laws. That's the conclusion of an environmental task force appointed by House Speaker Newt Gingrich to come up with a middle ground on environmental issues between conservative an moderate Republicans. Gingrich says the task force's statement is the foundation of a new environmentalism, which will define the environmental agenda for the 21st century. But the League of Conservation Voters counters that the report contains no new vision for environmental policy.
German auto giant Daimler Benz has unveiled what it calls the world's most environmentally friendly car. While the Nicar 2 should produce no pollution at all, it won't be available for at least a decade. From Germany, Michael Lawton reports.
LAWTON: Just a little bit of water vapor, that's all that comes out of the exhaust pipe on Daimler Benz's new electric car, or Nicar 2. The 6-seater van is powered by a small fuel cell, developed in cooperation with Ballard Power Systems of Canada. It uses an electrolytic membrane to control the reaction between oxygen and hydrogen, which produces electricity. There's no pollution, no carbon dioxide, and the vehicle can manage over 60 miles an hour and travel 150 miles on one tankful of hydrogen. The oxygen comes from the atmosphere. That's still not good enough for the production line, but it's a good deal better than Nicar 1 managed 2 years ago. That prototype had no room for anything but the motor and the driver. Daimler Benz says this fuel cell technology is the best bet yet for an alternative power source for the motor vehicle. Electric batteries are too heavy, and they simply transfer pollution from the automobile to the power station. Hydrogen gas is not an easy fuel to work with, but Daimler Benz is thinking of using ethanol as a source, which could be supplied at any gas station. That would mean there'd be some carbon dioxide, but still less than in the conventional engine. For Living on Earth, this is Michael Lawton in Cologne.
NUNLEY: Wild tigers are disappearing at the rate of one a day, and now stand on the verge of extinction. The World Wildlife Fund for Nature reports that habitat destruction and increased poaching means the global tiger population could be as low as 4,600. Wild tigers are still found in 13 Asian countries, including India and China as well as in Russia.
American geneticists may have found a way to save endangered sturgeon by identifying the origin of a sample of caviar. Writing in the journal Nature, scientists at the American University of Natural History say an advanced genetic technique can locate precisely where caviar comes from. That make it possible to determine whether the fish egg's source was legal or illegal. Currently legitimate caviar importers use their well-trained palates to guess whether a caviar comes from a legal source.
Several Colorado power plants have attached greenhouses to their facilities to make use of waste heat. And Colorado Public Radio's Kelly Griffin reports this first of a kind energy-saving experiment is producing big profits.
GRIFFIN: Waste heat generated by turbines is used to heat water, which is in turn pumped through the greenhouses. The largest operation, a glass-enclosed structure 30 miles northeast of Denver, produces 250 tons of vine-ripened unblemished tomatoes each week. Colorado Greenhouse grows the plants in nutrient-laced water, making it the largest hydroponic tomato producer in the country. The Boulder-based Colorado Venture Management, Inc. built the 4 power plant/greenhouse combinations. A spokesman says the company's goal was energy efficiency. It didn't expect much income from the greenhouses. But they make more than $30 million annually. Now, power plants in New York, Las Vegas and Pennsylvania have followed Colorado's lead. For Living on Earth, I'm Kelly Griffin in Denver.
NUNLEY: Education officials in a Florida county have withdrawn approval from an environmental science textbook, calling it anti-business. The action was taken after complaints by an executive of the Monsanto Chemical Company, a major local employer, and donor of money for local public education. The book, Environmental Science, Ecology, and Human Impact, published by Addison Wesley, was then removed from a list of textbooks approved by Escambia County for use in local schools. A review of the decision is scheduled for next month.
That's this week's Living on Earth news. I'm Jan Nunley.
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CURWOOD: This is Living on Earth. I'm Steve Curwood. For a newborn baby, there is no better food than mother's milk. It contains a perfect balance of nutrients, antibodies, and hormones, and the feeding itself helps to forge the vital emotional link between mother and child. But as much of Western society evolved, it began shaming women about their bodies and the exposure of their breasts. Many deemed breastfeeding crude and primitive, even though breastfed babies tend to have fewer illnesses and better growth than their bottle-fed brethren. Of course, some people have always breast fed, and recently activists have encouraged mothers to give it a try. But society is still uncomfortable with it. And now comes another major threat to breastfeeding: worry about pollution. Dioxin, PCBs and other persistent toxic chemicals in the environment, tend to concentrate in body fat, including milk fat, and get passed on to babies. Reporter Andrea DeLeon of Maine Public Broadcasting gave birth to her second child a few months ago. We asked her to investigate this worrisome trend, and share both her findings and her feelings about it.
(A baby babbles)
DeLEON: That's my son Carter. Four months old and he still wakes me each night at about this time: 3 AM, hungry.
DeLEON: I can stumble to the cradle in the dark, now, without knocking into the rocking chair. I take him into my bed to nurse. He stops crying as we lie belly to belly under the covers in the dark. In this position I can bend my face down to kiss the top of his fuzzy head, to breathe his baby smell as I doze. In all the chaos of my days, the only word that even comes close to these moments is peace.
DeLEON: Peace at least until a month ago, when I tuned my car radio to a speech about a health threat long suspected by scientists but only now gaining public attention.
(Lois Gibbs on radio: "Dioxin affects every man, woman and child. It comes from solid waste incinerators...")
DeLEON: The speaker was Lois Gibbs, the Love Canal homemaker who turned activist when she discovered her neighborhood was built on a toxic waste dump. Her topic: dioxin and a host of other persistent toxic chemicals which she says are waging covert war on the human population.
(Gibbs: "It goes out into the air, it goes out into the water, it gets into our food supply. It gets into the cow. When the cow is milked, it gets into our bodies. And ladies and gentlemen, the top of the food chain is our infants. Women who are breast feeding their babies are the top of the food chain. So when the cow is ... ")
DeLEON: That evening, when my son fell back, milk drunk and ruddy cheeked in my arms, I carried him upstairs with a sense of unease. Was he really as all right as he looked? I needed to know if my milk contained chemical time bombs that might wait half his life to go off. I called Dr. Beverly Pagan, a senior staff scientist at the Jackson Laboratory in Bar Harbour, Maine. She told me she hated to talk about contamination in breast milk, and then reluctantly agreed to meet with me.
PAGAN: Breastfed babies are taking in dioxin at a level that is 10 to 100 times more than an adult is getting. This is quite a serious issue. In fact, a breastfed baby takes in 10 to 15% of his entire lifetime dose during that first year.
DeLEON: Dr. Pagan told me that dioxin, PCBs, furans, and other persistent toxics have been entering my body in minute servings as part of the food I eat, and accumulating over my lifetime in my fatty tissues. I get my largest doses in meat, dairy fat, and freshwater fish. The older I get, the higher my levels become. When I nurse my son, Beverly Pagan says, toxics long stored in my fat migrate into the fatty breast milk.
PAGAN: Particularly, these chemicals are often an antagonist to the male hormone. These chemicals also might increase cancer in hormone target organs, such as breast cancer, testes cancer, prostate cancers. All 3 of these types of cancer are going up dramatically in America. And we don't know any reason, except for the exposure to these chemicals.
DeLEON: And there was more.
PAGAN: The sperm count in men has been falling. We think this is because of these hormone-disrupting chemicals, because most of them seem to interfere with the male hormone. We know that they can decrease sperm production in animals.
DeLEON: Breastfeeding is the only natural way humans can rid their bodies of some of these poisons, but with the demeanor of a friend breaking bad news, Pagan told me that most human mothers are carrying around enough chemicals to pose some threat to their children. But a single conversation and a couple of magazine articles didn't convince me that my own milk could bring harm to my baby. My bedside table sprouted stacks of literature on the subject. I read about the alleged dangers of nursing while nursing. I learned that the endocrine system is kind of like the postal service, delivering messages to all parts of the body, using cortisol to regulate my metabolism, releasing estrogen to trigger and modulate my reproductive cycles, telling my son's genes when to trigger each miraculous stage of his journey from egg to embryo to baby. I needed someone to explain how chemicals in such small amounts could affect my hormone system and my child's as well. If my endocrine system is the postal service, toxicologist Linda Birnbaum explained that dioxins, PCBs, furans, and certain persistent toxics were keeping some of the mail from getting through, delivering letters to the wrong addresses, or forging messages of their own. I reached Dr. Birnbaum in North Carolina, where she heads the Environmental Toxicology Division at the Environmental Protection Agency's Health Effects Research Laboratory. She says that while there's a lot researchers don't know about how these chemicals do their work in the human body, they do know a great deal about the effects of dioxin.
BIRNBAUM: In some cases dioxins have been shown to increase the levels of hormone receptors, in other cases decrease. In some cases dioxin lead to changes in the transformation of hormones, so there are a number of ways in which compounds like dioxins or PCBs or other synthetic chemicals can impact hormone systems. There's not a single mechanism that can explain everything.
DeLEON: And higher levels of these chemicals do not necessarily mean more troubling effects on the body. But hormonal disruptions are blamed for everything from neurological problems to suppression of the immune system. Dioxin also appears to interfere with insulin. Hormonal effects have been documented in seagulls in Canada, lab mice in Maine, and victims of an industrial accident in Italy. But none of this told me my son's risk. I weighed my years of vegetarianism against my fondness for tooling down the highway with a double cheeseburger balanced on my knees, my organic garden against the pint of ice cream in my freezer. I lay in bed in the middle of the night nursing, obsessing. Beverly Pagan suggests that women have their milk tested, but such tests can cost hundreds to thousands of dollars, and with so many chemicals out there which would I test for? More importantly, what would I do with the results? My son has to eat something, and in the first months of life the choices are limited to formula or breast milk. Everyone from the American Academy of Pediatrics to the formula manufacturers themselves says that breast milk is superior. Does the information coming to light about persistent toxic chemicals mean that's no longer true for some infants? Not from what scientists have learned so far. No one I talked with for this story told me to stop breastfeeding. Lactation consultant Bettina Pearson says a woman's breast milk is perfectly suited to her child at each stage of his development. It even serves as the infant's immune system in the first few months, until the infant's own immune system begins to function.
PEARSON: So in that interim, we are providing our babies with our antibodies, and our antibodies are specifically a result of what our own environment is. So the antibodies I make, being exposed to my 5-year-old for a newborn child, would be different than someone else. And each of our environments, what we're exposed to for illnesses or contaminants.
DeLEON: She says babies fed on breast milk spend less time in hospitals and have lower incidence of Sudden Infant Death Syndrome. They also have fewer infections and fewer allergies. I'm hoping Carter won't be plagued with the ear infection so common in young children. Though how my milk adapts to his needs remains something of a mystery. Bettina Pearson says formula could never show such response. Dr. Birnbaum of the EPA says a study underway in the Netherlands demonstrates that even breast fed children born to mothers with high levels of contamination are healthier than formula fed infants whose mothers have similar levels of persistent toxics. But no one knows for sure whether breast milk actually counteracts some of the very contaminants it contains. Pregnant and nursing women are left to consider the evidence for themselves and discuss it with their caregivers. So far, these discussions seem to be few and far between. My own midwife says clients have only just begun to raise the issue. My search turns up no doctors and only one midwife who regularly discusses the issue with clients.
DANIELS: Let's take a listen. There we go. Got the heart, and I can feel the baby thumping around in there, too. There's a kick.
DeLEON: Midwife Ellie Daniels runs her hand over a young woman's rounded belly, conducting a routine prenatal exam.
DANIELS: I think the baby has the hiccups.
DeLEON: She warns her clients to avoid freshwater fish, and the clams and lobsters that are a staple for many of the coastal Maine residents in her practice. One hundred percent of the women Daniels cares for breast feed their babies: an incredibly high rate. She encourages me to continue.
DANIELS: What could we find that is better? I mean, any milk source is going to have dioxin contaminants in it. If you feed a soy formula, you're feeding a formula that's made from the most heavily sprayed soils in the country, you know, the Midwest is in a terrible crisis with all of the chemicals that we've grown our crops with and sprayed on our crops. I mean, what can we find that is better? This is just a terrible situation.
DeLEON: This terrible situation is taking its toll on my breastfeeding experience, which was already almost as difficult as it is emotionally rewarding. I tote a breast pump and cooler everywhere I go, so that I can collect milk for my son when I'm not with him. It is a struggle to keep up with his needs and work full time. I eye the free samples of formula I brought home from the hospital. Child health advocates worry that information about the potential contaminants in breast milk will drive women like me away from breast feeding, even though none of the scientists studying the effects of persistent toxics believe women should forego nursing. Lactation consultant Bettina Pearson says American culture remains anti-breast feeding. Women are criticized for nursing in public. Television programs show only bottle-feeding moms. And employers are sometimes unsympathetic to workers' needs to express milk on the job.
DANIELS: Breastfeeding is so personal an experience, and I think women feel so vulnerable emotionally around it that if you're to say to them you could be poisoning your baby, the last thing they're going to want to do is breastfeed. So until we really know if there is a reason not to breast feed, even bringing it up I think is going to decrease the rates just because women are so conscientious about what they're doing.
(Carter laughs, babbles)
DeLEON: I'm still breastfeeding, despite all that I've learned about contamination. Because I believe it's the best thing I can do for my baby. I'll try to mitigate his exposure at the breast by feeding him a diet low in animal fat when he's ready for solid food. The thing that strikes me is that these chemicals are already being reduced in the natural world, and that is good news. The fish caught in the rivers near my house last summer are cleaner than those taken the year before. But these same substances will persist in our bodies, in our breast milk, and in the bodies of our children. For Living on Earth, this is Andrea DeLeon.
CURWOOD: Making America's green thumb greener. That's just ahead on Living on Earth.
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CURWOOD: According to most surveys, gardening is America's number one leisure activity. Last year we spent over $26 billion on flowers, lawns, equipment, and garden services. And most of this handiwork is done with what we now call conventional methods. Synthetic fertilizers and pesticides, and plants that originated in far off places. But in scattered plots around the country, gardeners are giving synthetic chemicals the green thumbs down and turning to organic methods. So we here at Living on Earth decided to get some dirt under our fingernails. We went looking for some advice about organic gardening. Evelyn Tully Costa is known to most of the world as a features producer for public radio. But to a lucky few, she's known as a professional garden designer. She's one of the owners of Garden Services, an organic landscaping outfit in Brooklyn. Welcome, Evelyn.
COSTA: Hi, Steve.
CURWOOD: Hey, listen, we called you because at last it is finally spring here in Boston. And we're really feeling the urge to get outside and do some planting.
COSTA: Well, you know, it's interesting, Steve. Maybe gardeners found what native peoples, animals, plants, poets, and even songwriters have known for thousands of years: there is no getting around the seasons, the sunlight, or the weather. Now lately, there's been a lot of attention given to this Seasonal Affective Disorder, or SAD. That's when some of us during the dark winter months, we slow down, we get depressed, we want to sleep and eat more. Just like some plants and animals. Now, in the springtime, everything comes out of hibernation including humans. Now, if that's a disorder, then perhaps we should quickly get the bears, the trees, and the shrubs into therapy. (Curwood laughs) Now, that urge that you talked about is a biochemical response to more sunlight. We share increased energy and excitement in the spring time with the living world around us because we're part of it. So it doesn't surprise me that gardening is America's number one leisure activity. It outpaces golf and even watching football.
CURWOOD: Okay, well in New York I suppose you have lots of therapists. But you're not in that business, you're a gardener. And you have a very successful gardening business, organic gardening business in Brooklyn. Have you always gone organic?
COSTA: No, I didn't. I mean, like a lot of people I started about 15 years ago, and like a lot of beginners I believed everything I read in the landscaping books. And of course everything you read is take this dangerous chemical and spray that and head for the hills. Now at that time I was using some pretty common but dangerous pesticides. And one day I thought to myself hey, wait a minute. If this stuff is deadly for fish, for pets, for children, what about me? So slowly I learned about organics and it just made a lot of sense to me. So I figured for thousands of years, humans have managed to grow delicious, beautiful plants on this planet without the benefit of petrochemicals. So the good news is that millions of people are still using these old methods and millions more are heading backwards. Or as I like to say, they're heading forwards into sensible gardening and organic farming practices.
CURWOOD: I've got to ask you, Evelyn, about the timing of all this. I mean, is it too late to start a garden this spring?
COSTA: Not at all. I think people should just relax and think of gardening as a big circle. Anywhere in the year they want to jump in, they can. Gardens go on for years; in fact, they never stop moving through the seasons. Now for every month, for every situation, there's something to do. There's no real beginning or end. Now for instance, if it's for the fall I'd be asking you to plant some shrubs and trees, build up your soil. In the winter time it would be time to start planning your gardening, ordering your seed packets. So there's always something going on. But the most basic rule is to know where you are going to do your planting. You have to figure out how much sun or shade your garden is going to have. Now this changes across the year, of course, so that' s something to consider. Get out a piece of paper, a pencil, a compass, figure out what direction your house faces -- that's north, south, east, or west -- and follow the shadows and the light across the day.
CURWOOD: Okay, so get paper, pencil, compass, check out the sun, check out temperature. I've got to figure out what my weather zone is here, right? And then when I get all this done, I can get some seeds, right? Or get a catalogue or something, and go down to the nursery and buy some things, right?
COSTA: Well, you could do all that. But I think there's something else that you really need to consider, that are more important than just flipping through the pages of a catalogue and ordering anything you want.
CURWOOD: Uh huh.
COSTA: And that's trying to learn what native plant province you live in. It's not just a matter of plopping in any old plant from anywhere in the world. Why not try to grow mostly plants, trees, and shrub varieties that grow naturally in a region? They're a lot easier to take care of, they attract native butterflies and bird species that otherwise have to look to exotics for their food supplies. Now, some of the regions that you might think about are eastern deciduous forests, coastal plains, central prairies and western deserts, just to name a few. So, the point here is really get to know your bio region, and you're doing this for a very practical reason in a very practical way.
CURWOOD: All right, I'll do that. But what's next?
COSTA: Well, I think the most important thing to do is get started. You can get a lot of good information at your local library, at your book store, botanical garden, plant society, garden clubs, get information from magazines. You can even get stuff on the Internet. Now, I think a wonderful book for first-time gardeners is The First Time Gardener. It's authored by Patty Barren and it's published by Crown. It's very simply and clearly illustrated, and it makes a lot of good sense for people making their first big foray into the wide world of gardens.
CURWOOD: All right, let's see, that's quite a list. Is there anything I can do quickly to get something going in the backyard?
COSTA: Why don't you start some seeds? There are so many new and innovative seed companies out there these days. They offer enormous variety of seeds that you can't get at your local nursery. Now, 2 seed types that you couldn't possibly mess up--
CURWOOD: I don't know about that --
COSTA: Are nasturtiums (laughs) we'll find out, we're going to do a test on these -- are nasturtiums and sunflowers. Try calling the American Horticultural Society's national information line at 1-800-777-7931. That's 1-800-777-7931. Not only do they give out general gardening information, but ask for their horticultural resource list. So for now just get out there, get some information, and start planning and planting. The next thing we're going to look at is soil. So the next time we talk, we're going to learn about how to size it up and how to improve it.
CURWOOD: Okay, I'll get some books and find out where the sun shines in my yard, and see what's growing there already. Maybe that will give me some clues about how rich or lousy the dirt is.
COSTA: That's right, you got it. Now, I would love to hear from your listeners about their gardens and perhaps with some of their questions.
CURWOOD: Okay, so we'll hear from you in a few weeks.
COSTA: Great. See you, Steve.
CURWOOD: Evelyn Tully Costa runs Garden Services in Brooklyn, New York.
CURWOOD: Now, if you have a question for Evelyn, write it down and send it to us at The Green Garden Spot, Living on Earth, Box 639, Harvard Square Station, Cambridge, Massachusetts, 02238. That's The Green Garden Spot, Living on Earth, Box 639, Harvard Square Station, Cambridge, Massachusetts, 02238. Be sure to include a daytime telephone number in case we want to use your question on the air.
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CURWOOD: Living on Earth is produced by the World Media Foundation, in cooperation with Harvard University and WBUR, Boston. I'm Steve Curwood.
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ANNOUNCER: Major funding for Living on Earth comes from the Ford Foundation for reporting on environment and development issues; the William and Flora Hewlett Foundation; all-natural Stonyfield Farm Yogurt -- whether supporting worthwhile causes or producing healthy foods, Stonyfield's goal is to make you feel good inside; the National Science Foundation for coverage of science in the environment; and the Great Lakes Protection Fund.
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NPR ANNOUNCER: This is NPR, National Public Radio.
CURWOOD: For most of us land animals, seeing is the most important sense. But if you live in the water, hearing is the key. But what happens if engines and other unnatural sounds clutter up the waterways? Noise pollution and marine animals coming up in the second half of Living on Earth.
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CURWOOD: It's NPR's Living on Earth. I'm Steve Curwood.
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CURWOOD: Four hundred and fifty five years ago, Spanish explorer Hernando De Soto reached the Mississippi River, making him the first European to lay eyes on the Big Muddy. Since then the Mississippi has been a major route of American commerce, and a large part of our cultural heritage. The Mississippi suffered for centuries as the main drain of America's sewage system. Over the decades pollution from cities, industry and agriculture eroded aquatic plants that support migratory birds and other wildlife on the river. Mink is one such species. It used to be abundant on the upper Mississippi until the 1960s when PCB pollution on the river was at its highest. Now the mink is coming back but its population is still less than half what it was just 40 years ago. In addition to pollution threats, the Mississippi and its natural inhabitants are under invasion from a host of alien species, also brought to the Mississippi by humanity. Chief among these are the zebra mussel and the purple loose strife, which have displaced native animal and plant species. Despite all this there have been no documented extinctions on the Mississippi since the 1800s. It seems that despite almost everything we can do to it, it is still the Mighty Mississippi. And for this week that's the Living on Earth Almanac.
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CURWOOD: They're sometimes called sea cows. Like the terrestrial version they are large, gentle, and slow moving, and subsist largely on grass: sea grass in this case. They were mistaken for mermaids by some of the early European sailors. Their more common name is manatees, and they're a marine mammal that lives in only a few areas of warm, shallow water. There are only about 2,600 manatees left in the waters around Florida, and today they are dying in record numbers. So far this year, more than 250 manatees have been found dead. In years past scientists could figure out what was killing most of them: collisions with boats, getting tangled in fishing nets, and the destruction of mangrove swamps where the animals thrive. Those dangers still exist, but this year there is a new and mysterious threat: a disease which scientists have so far been unable to identify. Nina Young is a marine mammologist at the Center for Marine Conservation in Washington. She says that what scientists do know is that the most vulnerable manatee population is being severely affected.
YOUNG: Primarily they have been adults, females that are either pregnant or lactating, which is also equally sad. Because again, we're removing animals from the ecosystem that are creating more, and we definitely need that in the case of the manatees.
CURWOOD: So the entire species is then at risk with this die-off.
YOUNG: Yes. We're very disturbed at the numbers. You know, 255 animals this year so far and we're, you know, one-third the way through the year, is pretty alarming.
CURWOOD: What does it do to the manatees?
YOUNG: Well, based on all of the autopsies that we've done, or they actually call them necropsies for marine mammals, we see that there's a lot of blood, hemorrhage in the lungs, the lungs are full of congestion. And there's various kinds of lesions and discoloration in the lungs. Almost something that you would expect to see in somebody who has died from pneumonia.
CURWOOD: So have they come up with any answers? Do they know what's happening to the manatees?
YOUNG: Not at this point. It's really something that's perplexing. All of the scientists that are working on this particular issue, all they know is they have this pneumonia, we don't know if it's virus-based or bacterial-based. But there is something that's causing folks a little bit of concern, and that's the red tide that's occurring down in that area.
CURWOOD: And what's the red tide?
YOUNG: Red tide is something that happens, oftentimes naturally, but it's often jump started when nutrients come into the ocean ecosystem when people fertilize in the spring especially. You get a lot of nitrogen and phosphates. And that allows for an algal bloom, and a red tide is a particular kind of algae that has associated with it a very poisonous toxin. We have had a couple of manatees come in lately that tend to have some kind of muscle twitching, neurological kind of paralysis. It's very hard for the animals to get to the surface and get air, and we actually down in Lowry Park Zoo, they've had people in the water with them 24 hours, kind of just lifting them up and helping them to get to the surface. And again they think that these symptoms are somehow tied to the red tide. That the breva toxin tends to have a paralyzing property to it if the animals inhale it or ingest it.
CURWOOD: Now, even if you could find out what's making these manatees ill, what steps could you take?
YOUNG: That's a really good question. You can't take them all out of the water. We have tried to capture some live animals to determine the status of their health. But even that doesn't give us any indication. So at this point it's kind of a wait and see: is it something that's going to pass? Is it going to continue? Is it linked to the environmental parameters of any kind of toxic dumping? We don't have any indication there. Is it linked to the red tide? We have some indication it may be that, and if the red tide passes, perhaps we'll start to see fewer animals dying as we do now.
CURWOOD: Well, I want to thank you for taking this time with us today. Nina Young is a marine mammologist at the Center for Marine Conservation in Washington. Thank you.
YOUNG: Thank you.
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CURWOOD: Usually we think of pollution as a thing: sewage, industrial chemicals, trash, which we can identify by sight, smell, or chemical testing. But what if pollution were not a substance but a wave, a sound wave? Throughout the depths of the world's oceans we've been causing such pollution for more than 100 years, and we know little about its effects on the billions of ocean dwelling creatures. A recent controversy over a plan to measure changes in ocean temperature by sending blasts of sound across the Pacific got producer Dan Grossman wondering what we do know about how marine animals use sound, and how sound pollution might be affecting them.
(Cetacean cries underwater)
GROSSMAN: I'm Daniel Grossman. Among all the ocean songs few are more intriguing than the music of the humpback whale.
(Whale songs continue)
PAINE: The first time I ever heard the sounds of humpback whales, I heard them in the boiler room of a ship with a lot of other noise going on, and a very dear friend of mine had been recording them. And he said here, let me play you some whale sounds, and I had never heard anything like it. It just completely blew my doors off. I was just stunned.
GROSSMAN: Biologist Roger Paine went on to publish the first study of humpback songs. He says the extraordinary melodies illustrate the importance to sea life, not just to whales but to many marine species, of hearing. In the turbid seas, vision is almost useless. Distant objects appear perpetually wrapped in fog. Sound, in contrast, travels well. Researchers say humpbacks may attract mates with calls heard tens or even hundreds of miles away. Dolphins echolocate or navigate with high-pitched whistles. Other ocean dwellers also sense their surroundings and communicate with sound. But ever since the industrial revolution, manmade sounds have filled the seas. Chief among these is the drone of the propeller.
(The sound of a propeller)
PAINE: And a propeller is a very noisy thing. And the result has been that we are polluting the seas with loud sounds, so the point where 24 hours a day the deep ocean is basically throbbing, roaring with the sounds of ships.
(Propeller sounds continue, followed by soundings)
GROSSMAN: The explosive clap of soundings to probe the ocean floor, and the piercing screech of military sonar add to the clamor.
GROSSMAN: Human activities now overwhelm the natural compositions of cracking ice, breaking waves, and animal cries like this narwhal.
(A narwhal cries)
GROSSMAN: Roger Paine was among the first scientists to warn that noise pollution might threaten the marine environment. Surprisingly, after searching high and low for proof, he's concluded, at least for whales, there is no threat.
PAINE: I've spent no small part of my life, many years actually, attempting to show effects of loud industrial noises on whale populations. But the evidence is that they continue to mate, they he being continues to find she or vice versa. And so my suspicion is that they probably are doing all right. That's a very dangerous suspicion because I haven't a particle of evidence except that the populations continue to reproduce, that it is correct.
GROSSMAN: But not all researchers are convinced the whales are doing all right.
(Sounds of scraping, paper shuffling)
TAYACK: Here we go.
GROSSMAN: Peter Tayack is an expert on marine mammal behavior at the Woods Hole Oceanographic Institution on Cape Cod.
TAYACK: Once one understands the importance of sound to these animals, and one has spent any time recording underwater, it's clear that there may be a potential impact of manmade noise.
GROSSMAN: Professor Tayack sat on a National Academy of Sciences Committeewhich issued a study of ocean noise in 1994. The committee concluded that the hubbub of human activities at sea could disrupt important behaviors of the ocean's inhabitants, like feeding and reproduction.
TAYACK: If whales are producing sounds as loud as they can in order to communicate over long ranges, say a male to find a mate, or a mother to keep in contact with its infant, then if the noise level rises, the range over which they can communicate may be lower. And this may seriously limit, say, the distance which an infant can move from the mother. Or it might limit the number of females that could respond to an advertising male, particularly if you already have reduced populations.
GROSSMAN: The Academy's panel warned that profound uncertainties remain, and recommended more research. Research like Peter Tayack's.
TAYACK: Let me show you some of the deflection of migration of whales. Let's see. (Pulls out a file cabinet) Here are tracks of migrating gray whales, gray whales migrating past the Big Sur coast, that were observed from a shore station.
GROSSMAN: Migration routes observed from the California coast show that undisturbed, the whales travel in long, straight lines. But another chart shows that when researchers play the sound of an oil rig from underwater loudspeakers, the whales alter their routes.
TAYACK: You can see that up here, kilometers away from the sound's source, the whales started deflecting either in-shore or off-shore of the source, and some of the whales got a more erratic, zig-zaggy kind of track.
GROSSMAN: In this experiment, the whales deviated only slightly off course, with no known long-term impact. But Peter Tayack worries that they might squander precious energy reserves if they made many such detours, or that mechanical noise could scare timid animals from critical calving or mating grounds.
(Low underwater growling sounds)
TAYACK: It was definitely a nail biter when we first released seals carrying these devices. Nobody had ever seen data of this sort.
GROSSMAN: This is the sound of an elephant seal swimming miles off the California coast. Peter Tayack's team built a lightweight instrument to record seals. The device, glued to seals' coats, permits researchers for the first time to swim alongside these nomads.
TAYACK: The device is so sensitive that we can actually hear every breath that a seal takes, and we can often hear its heartbeats. When they swim, we often can hear the swim stroke, can often hear a shhh shhh shhh, which can give you important information about how they're swimming. So this allows us to both record, what are the sounds a seal hears as it swims hundreds of meters below the sea surface hundreds of miles out to sea, and also how might this affect its dive pattern? How might it affect its heart rate or breathing pattern?
GROSSMAN: Elephant seals are especially interesting to researchers because they swim to great depths in the region of a natural conduit for ocean sound called the Deep Sound Channel. Discovered by Navy researchers in World War II, the Channel conveys sound unimpeded for thousands of miles. This unusual property has recently attracted the attention of climate researchers at the Scripps Institution of Oceanography in San Diego. They plan to monitor changes in ocean temperature by sending loud signals through this channel halfway around the world. In the process they hope to clock the pace of global warming. But some scientists fear the signal could harm deep-water animals like the elephant seal. Peter Tayack's research could settle the question.
GROSSMAN: This is the sound of a grouper. Although ocean noise pollution research has focused on mammals like whales and seals, there are plenty of other fish in the sea.
MERBERG: Not only are marine mammals affected by high noise levels in the sea. We also have every bit of supporting preliminary evidence that it also affects fishes.
GROSSMAN: Arthur Merberg is a professor of marine science at the University of Miami. He published one of the first papers suggesting manmade sound could be a threat to fish.
MERBERG: Coastal fishes, coral reef fishes, freshwater fishes.
GROSSMAN: And aquarium fish, like this domino damselfish.
MERBERG: Now the question is, how does it affect it?
GROSSMAN: Professor Merberg is seeking the answer. He begins by putting juvenile red drum fish in a chamber he calls a hearing tube.
MERBERG: And we determine their hearing ability from the low frequency of about 200 Hertz up to about 1,000 Hertz.
GROSSMAN: Frequencies like this.
(A low beep)
GROSSMAN: And this.
(A switch clicks; higher beeps sound)
MERBERG: And after a conditioning, a training period, they tell us by specific movements: do they hear the sound or don't they hear the sound?
GROSSMAN: Professor Merberg moves them to a tank where he blasts them with pulses of sound 50 times louder than the faintest sound they can hear.
GROSSMAN: Then he returns them to the hearing tube.
MERBERG: And we again examine their hearing ability. When we do this, we find that they have decreased hearing.
GROSSMAN: That's bad news for fish in the wild.
MERBERG: The decreased hearing ability, you now start to affect what the function of sounds are to fishes, such as identifying individuals of a colony, individuals recognizing members of one's own species, detecting prey. So therefore, you're affecting the survival and reproduction of species.
(An elongated beep continues, ends.)
KATTEN: We have ears from humans, ears from seals, ears from manatees...
GROSSMAN: Biologist Darlene Katten is up to her ears in auditory organs. A researcher at Harvard University and Boston's acclaimed Massachusetts Eye and Ear Infirmary, Professor Katten uses high tech medical diagnostic tools to make detailed images of these animal parts. By looking carefully at the ear's anatomy, she infers what frequency an animal can hear and how well.
KATTEN: What I do is to get the ears from these animals, or the heads, after they've stranded and died, for instance, and then analyze them for the structure and look at the structures to figure out what they're hearing. (A door shuts.) At the moment, in the freezer, we have heads. We have some heads from stranded marine mammals, and we have a baby hippo head to look at as well.
GROSSMAN: Professor Katten's ability to interpret X-ray images has earned her the respect of surgeons who consult her before operating on people with hearing problems. Her research focuses primarily on marine mammals. But she also gleans important information from other aquatic species, like sea turtles and the baby hippopotamus, whose head she's examining today.
KATTEN: So let's go take a look at the hippo.
GROSSMAN: The researcher removes the frozen head from a plastic tub.
(Head bangs against tub)
GROSSMAN: It has long, stiff whiskers and shiny gray skin. She puts it on a narrow table of a CAT scanner, where just moments earlier a young man with hearing trouble was examined.
(Buttons are pushed, beeps sound)
GROSSMAN: Darlene Katten watches intently at a screen displaying images recorded by the scanner. With this device, she can literally look inside the head of a whale or seal and learn what it can hear. She and other researchers have discovered that the ratio of hearing nerve cells to sight cells is 20 times higher in some whales than it is in humans.
KATTEN: There's your ear. And he's got lots of fluid up in there. I'm looking at the world through the eyes or the ears of these animals that have capacities I don't have. So I get to hear, in a sense, what the ocean sounds like to a dolphin, or what it sounds like to a blue whale.
GROSSMAN: Blue whales hear infrasonic frequencies, much lower than the human ear does. In contrast the bottlenose dolphin, also classified as a whale, is most sensitive to ultrasonic frequencies, much higher than humans can detect. So the same supertanker rumble that might be deafening to the whale would be almost inaudible to the dolphin. This dramatic variation between animals complicates the task of assessing the impact of noise pollution.
KATTEN: Impact is a very complex combination of an animal's sensitivity to the sound, the health of its ear, and the absolute intensity. So it isn't one number. You can't say that oh, a 200 dB sound, is going to impact every ear exactly the same way.
GROSSMAN: Professor Katten agrees that so far the case against manmade industrial noise is inconclusive. But unlike biologist Roger Paine, Darlene Katten is concerned.
KATTEN: Clearly humans are dumping a lot of sound into the ocean. We're using it for our commercial purposes, we're using it for exploration. We're using it all the time for recreation. And I expect we are having an impact. It would be somewhat naive to think that we weren't. What we have to decide as humans is whether we're willing to take the risk of changing that environment, impacting the animals in exchange for what we see as our benefits.
GROSSMAN: Countless marine animals share the world's seas with some 28,000 cargo, military, and research vessels. They're often in close contact, as in this recording of humpback whales diving near a boat in Alaska's Glacier Bay.
GROSSMAN: Glacier Bay has some of the country's strictest rules to reduce the impact of noise and other disturbances on marine life.
(Whale sounds continue)
GROSSMAN: Biologists here want to study the acoustics of ships entering the bay in order to give preference to those with the least impact. They say if the tide is ever going to turn against noise pollution and toward quieter ships, it may start here. If funded, the study could begin this summer. For Living on Earth, I'm Daniel Grossman in Boston.
(Whale sounds continue)
CURWOOD: California is taking a bold new approach to fuel spills from some underground storage tanks. It's decided to do nothing at all. Details are just ahead on Living on Earth.
(Music up and under)
CURWOOD: It's Living on Earth. I'm Steve Curwood. In the early 1980s it was discovered that many underground tanks at gasoline stations have been leaking fuel. After decades in the ground they were corroded, and some were polluting groundwater especially in older urban areas. The Federal Government and the states went to work. California, for example, required a cleanup of all sites where groundwater was contaminated or threatened. But a new study has led California's water agency to recommend shutting down some of the cleanup sites. Instead, they say the state should just let nature take its course, as naturally occurring microbes in the earth slowly eat the fuel up. But as Cheryl Colopy reports, some critics say the state is moving too fast.
(Sound of a vacuum)
COLOPY: On a street corner in downtown Oakland, beneath the side of a former Chevron service station, an underground vacuum sucks up gas fumes day and night. The process is called soil vapor extraction. It's one of the latest and most expensive methods of mopping up fuel that's leaked from old storage tanks.
(Vacuuming sounds continue)
COLOPY: The Federal Environmental Protection Agency says there are 300,000 sites like this nationwide and that cleaning them all up could cost $32 billion. But here in California, scientists say there may be a cheaper way to do the job. David Rice calls it bioremediation: letting microorganisms already present in the soil eat up the fuel.
RICE: We had a spill of about 12,000 gallons. We found that the microbes could digest that 12,000 gallons in about 6 days under ideal conditions.
COLOPY: The kind of ideal conditions that exist here at Lawrence Livermore Laboratory, near San Francisco. David Rice, who directed a bioremediation study for Lawrence Livermore, says fuel is just another meal for the microbes. They've been consuming the byproducts of decaying plants and animals for millions of years. They're greedy and they're free.
RICE: And what we found was that there are a whole variety of microbes and there's a very rich population, and if one doesn't like a certain condition another one takes over. So it's not just one microbe. There are a very rich ecology in the subsurface which acts to chew apart the carbons.
COLOPY: David Rice, along with scientists from the University of California, studied 1,500 leaking underground storage tank, or LUST sites, throughout the state. They found that at 80% of them the fuel doesn't travel very far or very fast, partly because microbes keep it in check.
KOLB: These fuel sites don't pose big threats to major public water supplies.
COLOPY: Larry Kolb of the San Francisco Bay Regional Water Quality Control Board urged the state water board to take a close look at the Lawrence Livermore study and loosen up its regulations for cleaning up leaky storage tanks.
KOLB: Because these fuel sites, the old gas stations, typically are local, they're only shallow aquifers that are affected. In most cases the gas has only gone 100 feet or a couple hundred feet.
COLOPY: The state water board agreed, and now allows regional water quality districts to use bioremediation at low risk sites. Even though microbes may take up to 10 years to digest a spill, the most common alternative, pumping water out of the ground, then treating it, could cost $3 billion. Many cleanups are paid for by a surcharge on gasoline, and John Marshak of the Central Valley Regional Water Board says maybe the state should raise that tax instead of lowering its cleanup standards. He's worried that using microbes to save money is putting California's drinking water supplies at risk.
MARSHAK: And that's really what this entire Lawrence Livermore debate has done. It's put the regulators in the position of having to prove that there is a problem.
COLOPY: The Sierra Club's legislative director in Sacramento. Bonnie Holmes, agrees. She says that based on the Lawrence Livermore report, more than half the cleanup operations in California are being shut down in favor of bioremediation: a trend she warns other states not to follow.
HOLMES: I would be very concerned that other states not take this report and use it prematurely to shut down soil remediation at soil only and shallow aquifers. It's far too premature, that we see a lot of flaws in the report. The report has not been peer reviewed.
COLOPY: The Environmental Protection Agency says that sites where bioremediation is used have to be watched carefully to make sure the spills are really shrinking, and the EPA is providing states money for the monitoring effort.
(Office sounds. A phone rings. A woman answers: "Good afternoon, Weiss Associates. Hi.")
COLOPY: Weiss Associates of Emeryville was one of the first California firms to get into groundwater cleanup. You'd expect its president, Richard Weiss, to be worried about losing business now that so many groundwater cleanup sites are being shut down. But he says regulatory change is long overdue.
WEISS: In my opinion, what really happened is there were some very bad contaminated sites that did have really adverse effects. And what happened is that the public then generalized from these really bad cases to anything that has to do with contamination or toxicity in sand and basically use the big hammer, and it's like indiscriminate, anything that has to do with contamination we're going to treat it like it's the blight on the earth.
COLOPY: A hydrogeologist himself, Weiss says leaking fuel shouldn't be confused with leaking solvents such as those used in dry cleaning and computer chip manufacturing. They're much more carcinogenic, he says, travel farther and faster than fuels, and have fewer natural enemies in the soil. But at Stanford University, researchers are experimenting with microbes that may someday consume solvents, too. For Living on Earth, I'm Cheryl Colopy reporting.
(Music up and under)
CURWOOD: And for this week that's Living on Earth. Our senior producer is Chris Ballman. Our editor is Peter Thomson, our director Deborah Stavro. Our production team includes George
Homsy, Kim Motylewski, Constantine Von Hoffman, Liz Lempert, Jan Nunley, and Julia Madeson. We also had help from Susan Shepherd and Emily Atkinson. Our engineers in the WBUR studio are Frank DeAngeles and Mark Navin. Our Harvard University engineers are Larry Bouthellier and Jeff Martini. Michael Aharon composed our theme. I'm Steve Curwood, executive producer.
(Music up an under)
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