January/February 2003

Scary chemicals that mess with our hormones

An Interview with Theo Colborn, Ph.D.
By Ravi Dykema

      Over the last 10 years, a growing number of scientific studies have shown that fetuses can be harmed by exposure to certain synthetic chemicals. These are chemicals that disrupt the hormonal signals that direct fetal growth, with devastating effects on the development of the individual. Some of these impacts include genital abnormalities, diminished fertility and behavioral disorders. Unlike carcinogenic compounds, these chemicals-known as hormone disruptors-can wreak havoc even in infinitesimally small amounts. And these chemicals are ubiquitous in our daily lives, appearing in products ranging from compact disks to cosmetics to water bottles.

      Theo Colborn, a Colorado resident and a senior scientist with the World Wildlife Fund U.S., is one of the world's leading authorities on endocrine disrupting chemicals in the environment. She is also the co-author, with Dianne Dumanoski and John Peterson Myers, of Our Stolen Future (Penguin USA, 1997), which examines the terrifying impact of synthetic chemicals, especially on fetuses. In this interview with Nexus publisher Ravi Dykema, Colborn discusses how hormone disruptors interfere with normal growth and development, where they're found in the environment, and ways we can protect ourselves and our children.

 

RD: How did you come to be interested in hormone disruptors?

TC: I became concerned about the quality of water in the western United States in the mid 1970s. No one seemed to care about the quality of the water-they were thinking only about who owned the water. But water is a life support system-and at great risk out here. We don't have abundant supplies of ground water that we can count on, or big rivers like they do in the East. So, at 51, I went back to college, to Western State College, to become an expert in western water quality. I got my Master's degree there, then went to the University of Wisconsin in Madison for my Ph.D. While there, I was given an application to apply for a Congressional Fellowship with the Office of Technology Assessment, which was Congress's think tank. To my amazement, I got the fellowship. I had never been actively involved in policy determinations in the past. I just knew that what the government did at times was wrong.

RD: What were you doing for the Office of Technology Assessment (OTA)?

TC: I had hoped to do a study on Western water quality, but at that time, the OTA was gearing up for a big study in anticipation of the re-authorization of the Clean Air Act. Since I had been very involved with an environmental group tracking the impacts of coal-fired power plants, oil shale development and air quality, that sort of thing, they put me on the team that was working on the report for Congress on the state of U.S. air quality. I worked on the toxics part of it-the human health, eco-health and wildlife health part of the work. When Congress got around to re-authorizing the Clean Air Act, they chose to ignore the toxic chemical evidence provided.

RD: How did you get on the trail that led you to hormone disruptors?

TC: Just before I was getting ready to leave Washington, I got a phone call from Dr. Richard Liroff at the Conservation Foundation. He told me he had been asked to write a book on the state of the environment of the Great Lakes. He said he was a political scientist, and he would have four more policy experts working with him. "You will be our scientist," he said.

      While I was at the University of Wisconsin, Madison, I had been very concerned that no one was paying attention to what led to the disappearance of the top predator fish in the Great Lakes, and that those who should have been paying attention were ignoring the bio-accumulation and the bio-magnification of toxic trace chemicals in animals through to the top of the food chain, including humans. So I joined the project.

      It was while we were working on the book, which we called Great Lakes: Great Legacy?, that we discovered that certain synthetic chemicals were passing from one generation to the next in animals in the region-especially those animals that were dependent on the Lakes for their food. The adult animals looked fine, but the youngsters were not thriving well at all. It became evident that we had not thoroughly tested chemicals for their safety and the risk assessment approaches our government was using were not adequate. This concept prompted entirely new approaches in research. For example, there is a very convincing link now between pre-natal exposure to toxic chemicals and brain development. It's very, very disturbing.

RD: What do you and many other scientists suspect is going on regarding man-made chemicals and their effect on humans? We know many of them are carcinogens, but aren't you onto something new?

TC: Our knowledge of this is new, but the issue is not-it's been happening to us without our knowing for many years. Since the 1970s, there's been a tremendous increase in human disorders, including childhood diabetes, childhood cancers, childhood arthritis, early puberty, ADHD-like learning and behavioral problems, autism, thyroid disturbances, juvenile delinquency, juvenile violence, hypospadias and other external genitalia abnormalities in males, testicular cancer in young men, and an increase in gonadal cancers in middle aged and older people. Through laboratory studies, most of these disorders can be traced back to an event that takes place in the womb. Making a causal link between a particular disorder and a chemical may never be possible because there are so many chemicals in use today and it is a long time from exposure to expression of the disorder.  But there is enough evidence from human epidemiological and laboratory studies to realize that what we are doing today is changing the destiny of those people who are exposed to chemicals in the womb.

RD: You said there has been a tremendous increase in these problems since the 1970s.

TC: During and after World War II, we began to flagrantly use synthetic chemicals. These chemicals were tested for cancer, obvious birth defects, skin and eye irritation, mutations and convulsions. If they passed those tests, in most instances, they were considered safe. By 1950, mothers began to give birth to the first generation of people born who were exposed in the womb. On top of this prenatal exposure, this first generation was also building up more chemicals in their body as a result of postnatal exposure. So by 1970, the second generation of individuals with prenatal chemical exposure was being born, and that would be when population impacts might begin to appear.

RD: What do you mean by a population impact?

TC: If you have one person walking around with diabetes, you don't think you have an epidemic. But when you examine populations or groups of people in communities or geographic regions and you look at the percentage of those people in the population that has diabetes, you can begin to see the extent of a disease or disorder.

      There has been almost no systematic record keeping of non-communicable disease in this country-like cancer, for instance. Birth records do include obvious birth defects but they will not pick up the delayed impacts of prenatal exposure such as those disorders listed above, except for hypospadias. Hypospadias is obvious at birth-it is a condition in which the urethra doesn't open at the end of the penis. That indicates that the infant boy's hormonal balance (internal chemistry) was disturbed in the womb so that he didn't get the correct hormonal signal at the critical time when the penis and urethra begin to enlarge and lengthen together. The hormone is called dihydrotestosterone. There is a growing list of synthetic chemicals that cause this problem in laboratory animals. These are called antiandrogens and up until eight years ago, no one knew that there were antiandrogens in the environment. We've now reached a point where one in 125 boys in this country is born with hypospadias, and in some areas, it's much higher.

RD: Do you think an ordinary urologist would know of the link between hypospadias and synthetic chemicals?

TC: Often, urologists will say the condition is familial or genetic. But it just may be that the whole family has been exposed to the same chemical. I published a paper on hypospadias last year with one of the top pediatric urological surgeons in the country, Dr. Larry Baskin from the University of San Francisco Medical School. In the paper, we discuss all the risk factors, and there are many, including the age of the mother. We looked closely at the findings on genetics, and it's very obvious that maybe only five percent of the cases are genetic.

RD: The rest are the result of hormone disruptors?

TC: Well, it is now well established that something is interfering with the production of dihydrotestosterone in the embryo at the time of sexual differentiation, when hypospadias would commence. In addition to hypospadias, autism was traced back to chemical influences in the womb in one study.

      I recently published an article on the possibility that some autism cases could be the result of exposure to chemicals. In the laboratory, if you expose the developing hypothalamus to chemicals, it develops much more rapidly than it should. The children with autism have heavier brains, and what is called the "packed-cell syndrome." Interestingly and conversely, a growing amount of evidence points to PCBs and dioxins interfering with brain development, causing the brain to be smaller-and these children have various manifestations of brain disorders, such as ADD and ADHD, behavioral changes, and learning impairment.

RD: In addition to evidence in the human population, don't you also have evidence in the animal population?

TC: Yes, we do. For example, the Great Lakes Water Quality Agreement was signed in 1972 by both the governments of Canada and the U.S. At that time they agreed to clean up the lakes. When we did our study in 1987, we found that the obvious garbage and algae blooms in the Lakes had been reduced considerably, but the big silent killers-the chemicals, like PCBs and dioxin-were still out there. For years, we were looking for things that bioaccumulate and therefore biomagnify in animals. We found that PCBs were biomagnifying 500 million times. That means that the concentration of the chemical in bald eagles, one bird that was studied, was 500 million times greater than the concentration in sea water. This, of course, made the chemicals easy to measure in the animal tissue.

RD: So, you could find them easily in bald eagles, but it was very hard to find them in the water?

TC: That's exactly right. Biologists were using the animals to measure the chemicals. Biologists suggested that we use the bald eagle as the model of the state of health of the Great Lakes, because they thought when the bald eagles could reproduce again along the shoreline of the Great Lakes, they would know the Great Lakes were cleaned up. It was a great idea-using animals' biomarkers as a measure of ecosystem health.

      Recent core drills in the Great Lakes have shown that in the '30s and the '40s, there was so much dioxin in the lakes that no lake trout or herring could have made it through adulthood. In the meantime, Canada and the U.S. are spending approximately $50 million per year to stock the lake with these fish because they still can't reproduce there. The Great Lakes fish are, by and large, reproducing in fish hatcheries and then stocked. They grow to adulthood, but don't reproduce-by the time they reach adulthood, they have turned into what are called hermaphrodites. They're bisexual. The males have female gonads, and the females have male gonads. Oftentimes, you can't tell the sexes apart. They look very much alike.

RD: So, toxins in our environment are finding their way into our bodies. It sounds like scientific evidence is pointing to a horrible phenomena.

TC: It is a dilemma for sure. And we now know there are a lot more chemicals out there than the PCBs, dioxins and DDT. They're very persistent and long-lived chemicals. The newly discovered chemicals that can interfere with development and function may not be as persistent but they are often present in the immediate environment. In the case of these newly discovered chemicals, when you talk tonnage, you have to talk in terms of millions of tons being produced. They have been used in commerce for years, but they were given little attention by chemists and biologists. They are basic components of plastics and materials that are used in plastics to make them fireproof and flexible, etc., and these plastics are in our everyday lives. This is where it gets to be very difficult for the person who is trying to avoid exposure.

      It was interesting trying to remodel my little house with what are known safe materials. I laugh at what I went through to try to find materials that didn't have certain plastic and volatile components in them. The new chemicals of concern are in fire retardants, water repellents and stain resistors-they are in computers and monitors and telephones, in compact disks and in the bottles we that carry our water in. They line food cans. These chemicals are released all the time in very, very small quantities. One of them, bisphenol A, causes the prostate to become enlarged in male mice before the pups are even born, and the prostate stays enlarged throughout adulthood. It also changes the development of the mammary gland. It programs the glands with what are called "hormone receptors," so the glands sometimes are a little heavier and their structure is different. Scientists are making breakthroughs in laboratory studies where they are demonstrating how the glands that are exposed during development and have more hormone receptors (such as estrogen receptors) are more prone to developing cancer as the animals age.

RD: Now, is it true that these man-made chemicals, such as PCBs and dioxin, have their worst effects on an unborn child?

TC: Exactly-they affect how a woman's child is constructed. They can affect its immune and metabolic systems, the brain, even the morphology of the reproductive tract in insidious ways that are not often expressed until the child reaches adulthood. The developing embryo is the most vulnerable to this kind of disturbance.

RD: How do these chemicals get into a woman's body?

TC: Industry spokesmen claim that you can't find these chemicals in the human body or, if you do, the concentrations are so low that there is nothing to worry about. The Centers for Disease Control and Prevention is now doing a nationwide study where they are collecting urine from thousands of people. They began by looking for 27 chemicals. What they discovered was that lead levels were lower than they were many years ago, and cotenine, which is the side-stream product of cigarette smoking, levels in urine had come down. But what they were surprised to find was that women between the ages of 20 and 40-the childbearing years-were carrying nine times the concentrations of two specific phthalates in their urine. Phthalates are among chemicals that can cause hypospadias. They also affect the thyroid system, and therefore could affect the developing brain as well. These particular phthalates are found in nail polish and cosmetics and perfumes. Since they were found in the urine, there is no denying that the chemicals were in the women's bodies.

RD: So phthalates disrupt hormones, and hormones effect a growing fetus?

TC: Yes. From the moment of conception until you were born, you were solely under the control of hormones and their auxiliary signaling chemicals. Those are the natural chemicals that are instructing your genes on how to develop. They govern the formation of the fetus at every stage of development, and throughout life. But it's prenatally that they have the most effect. Think about it. At conception, you've got a sperm in an egg-you can't have much else in that cell. With only 1/10 of a trillionth of a gram of a shift in one of the sex hormones in the womb environment, sexual behavior and development of the gonads and reproductive tract is changed in a laboratory animal. Dioxin has effects such as this at low doses. So do some of the PCBs. In some instances, bisphenol A has been demonstrated to do this in the lab as well. These effects are found at parts per billion and smaller doses. And the list of chemicals that behave like this in the womb environment is growing.

      The rest of the story is, where did these phthalates come from? They were able to trace phthalates back to cosmetics, perfumes, detergent, cleaning compounds, nail polish, shampoos, conditioners-all the things women use in their daily lives, and we always thought they were safe. And what are women doing? They're primping with these products to attract a man so they can get married and have a child.

RD: Where else are phthalates found?

TC: They're everywhere-I suspect that they're even in glue, like the glue used to stick labels on organic foods in health food stores.

RD: So shopping in health food stores doesn't necessarily protect us from these chemicals?

TC: People should still buy organic, because we've got to protect the environment and people working in the fields. When you buy organic, you're protecting thousands of other people and children through the reduced use of pesticides. And even though it costs a little more, people should tell themselves that this is something they can do for future generations, to protect the thousands of migrant workers who are exposed where chemicals are used, as well as protecting themselves.

RD: So what can we do? Maybe my daughter's mother can't do anything about what she may have passed on to our child. But my daughter is 14, and I wonder what she can do to protect herself.

TC: It's very important that you think very carefully about what your daughter eats. For example, farmed salmon. Don't feed her salmon unless you know where it's coming from-farmed salmon is highly contaminated with PCBs and other persistent organochlorine chemicals. The salmon are being fed fish, so the farmed salmon has just moved up higher in the food chain. It came as shock to everyone, even the chemists doing the work, to learn about the concentrations at which PCBs, DDT and other organochlorine chemicals have accumulated in those fish. On the other hand, we need to eat fish for health reasons.

RD: What are some other ways we can protect ourselves?

TC: Unfortunately, it's getting harder and harder to avoid these chemicals in our modern life. I could not have flown out here to Colorado in an airplane without bisphenol A, for example, which when brominated is an excellent fire retardant. And practically all our clothing is impregnated with fire retardants-a lot of them can't be sold unless they're treated with fire retardants. These chemicals have improved our lifestyle, but they're failing our progeny in many ways.

      But there are ways you can avoid many of them. Certainly avoid cosmetics and perfumes. Wash your hands more frequently just as you should to prevent bacterial and viral contamination, because you're handling chemicals that can be swallowed and/or absorbed through your skin. And definitely avoid pesticides-start switching to boiling water for ants and swatters for flies and that sort of thing. Pesticides pose a serious dilemma. Paonia, where I live, is in a mosquito control district and the managers of the district have announced that they are going to start spraying with malathion on a regular basis next summer. One of the members of the mosquito board actually said, "We can spray our children. It will not hurt our children."

RD: And malathion does what?

TC: It has been shown to affect the thyroid system, the adrenals and the immune system even at low doses. It has affected testicular function in lab animals and suppressed growth rates, besides being designed to affect the nervous system that can lead to respiratory failure. It's a hormone disruptor. We have pharmacists in town who aren't dispensing anywhere near the amount of toxic chemicals that the high school boys mix and spray around the town of Paonia. They ride around in open trucks with their arms out the window-they don't wear masks-as they're applying the chemicals. No one knows yet what the delayed health effects might be from exposure such as this.

RD: Do you think filtering our municipal water that comes out of our taps is a good idea?

TC: No, I don't like filters, because I don't think they're trustworthy. If you change the temperature of the water, you may release something that's in the filter that collected there that becomes soluble at a higher temperature. Also in filters, you can get a buildup of bacteria that don't need oxygen. These are called anaerobic bacteria, and they can be very harmful. How do you know when the filter is saturated? I have always recommended distilled water. I have had a distiller in my home for years. It also gets rid of the parasites, giardia, metals and organic chemicals. This is nature's way of purifying water-through evaporation and condensation.

      For a number of years, you could buy distilled water or its equivalent in pint bottles. Some companies use reverse osmosis, which is all right where the water is being tested regularly. Then some companies re-constitute the water by putting minerals back into it to satisfy people's taste and for those who think they get their nutrients from their drinking water. This is a ridiculous concept. But anyway, there's a lot of good, reconstituted, filtered or distilled water on the market. The cheapest way is to buy the gallons of distilled water. Of course, they're in a plastic bottle, which is a problem.

RD: How wary should we be of plastics?

TC: I think until industries have to meet higher standards for their plastics, they should be avoided. Never heat anything in the microwave in plastic, and don't pack food in plastic. I've switched to all jars again. And you can use aluminum foil, but then you have to think of the energy and environmental impacts involved in producing the aluminum. Some entrepreneur should start recycling aluminum from our dumps-there's so much there. Remember, when the label on a food product says "microwave safe," that is based on whether the product has been shown to be a carcinogen or not. There are no tests yet for endocrine disruptors.

RD: So you think it would be better to change the manufacturing process of plastics.

TC: I do, but until we get a set of screens and assays to test chemicals for these effects, we won't know whether the new product is safer. There are new plastic products coming out of Japan that are made from algae-they're not petroleum derived. You see, every chemical I've talked about has been petroleum derived. As long as we keep guzzling gasoline and crack crude oil, the pesticides and industrial chemical industries have cheap source material. If we stopped using gasoline, I think the algae-derived plastic would solve our problem.

RD: Are there any other things you could name that you think we should do, like move out of cities that have air pollution?

TC: Moving out of cities requires the use of automobiles. There are surely some of the chemicals of concern in the cars, and the cars burning diesel or gasoline are releasing dioxin. Every time you run an automobile, you're releasing dioxin in very small amounts. But these very small amounts add up and have a cumulative effect. There are other chemicals that behave like dioxins to which you are exposed, which basically use the same mechanism to cause their toxicity. So you also get the additive biological effect.

RD: Meaning that a combination of chemicals can constitute what would have been a higher dose of one of them?

TC: That's right. But the big concern is that when you put chemicals together, you don't know how they'll work in combination. Every now and then a scientific paper will reveal unexpected interactive effects of two chemicals at concentrations well below where they would cause any other effect if administered alone. This is quite scary when you think of the number of chemicals we are exposed to every day. You'd never get to the end of the problem.

RD: So, Theo, how far away do you think society is from responding responsibly to this threat?

TC: I'll be quite honest with you. In the last three years, I've seen an explosion of scientific literature defining the problem of endocrine disruption. Today, we've got new-age toxicologists who are thinking outside the box-not like the old-age toxicologists who continue to use crude measures to determine chemical safety. We've got geneticists who are beginning to understand this, evolutionary and developmental biologists who really get it. Journals are full of papers from teams of people in different departments and from different campuses across the country working together. They are not going to let this issue die.

      For example, within the last month, several of the papers have been unbelievably amazing. I just got one from Japan yesterday looking at umbilical fluid and amniotic fluid. A team of gynecologists and obstetricians have measured bisphenol A in the amniotic fluid of pregnant women and found that at one period during development in the womb, the concentration soars, and it's right around the time when organogenesis is taking place. They don't know why. This indicates that the embryo is much more at risk than was expected.

RD: So scientists are going at this from many different fronts.

TC: That's right. And they are going to keep alive the search for more answers.

RD: It sounds like scientists are very alarmed, or at least very curious.

TC: Yes, but our government appears to be cutting off funds for this kind of research. There is little obvious support earmarked for this kind of research if you read the anticipated federal budget for next year. It's almost like they've forgotten about it.

RD: You mean they're acting as if hormone disruptors aren't any problem at all?

TC: Yes, there seems to be reluctance to use the term and call a spade a spade. On the other hand, I've seen an explosion in the use of the term "endocrine disruption" in the scientific literature. We used to get five to 10 to 15 papers a month back when I first started doing this work, because endocrine disruption only came into the scientific terminology in 1992, after the publication of the first comprehensive technical book on the issue. But now, endocrine disruption is appearing in at least 500 scientific papers a month. My database is growing like you wouldn't believe. And then the other thing that is catching on is the lay press, newspapers and especially women's magazines, and this interview with you, for example. Every day, it seems that somewhere the term turns up in the media.

RD: So it will enter the political arena before long.

TC: Hopefully.

RD: And if it enters the political arena accompanied by indignation or terror, then those who didn't act earlier will be held accountable. Politicians must be thinking that way.

TC: Yes, they must. The interesting thing is, a bill, HR4709, was introduced in the House by Louise Slaughter last May. She's a long-time congresswoman from Rochester, NY. She's tough on industry, and has a good record on the environment. The bill is called the Hormone Disruption Research Act of 2002. Over a year ago, shortly before September 15, 2001, we were trying to get a hearing on hormone disruption in the Senate, but because of 9/11 it never made it. Which is a shame, because we found a number of senators and representatives who understood and were sympathetic to this issue. I have spent part of my time over the last five years walking around Capitol Hill, popping in people's offices, and just telling them about hormone disruptors-not asking them for anything other than to listen. We are fortunate to have many Senators and Representatives in Washington who know about endocrine disruption or environmental hormones, but that is not enough. One of the lessons I have learned is that unless our elected officials hear about an issue from the people who elected them, they really have no reason to press forward on it. There are too many other issues they are hearing about from their electorate that they must address first. So terrorism, prescription drug prices, jobs, etc. are high priority.

RD: And they can't stick their neck out for hormone disruptors.

TC: That's right. The point is, they're saying to me, "Look. I don't hear about this from my electorate."

RD: So the issue has to go through the press to the electorate?

TC: That's right. They say, "How can I introduce this bill that will need $100 million a year for five years in a tight budget year?"

RD: It sounds like there are some good signs. There's media interest. Congress is listening. And scientists are excited. So what's your best guess? Are we five years, or 10 years or 20 years, from having a response that changes the outcome in our offspring?

TC: Oh, that's going to take two to three generations, maybe more. I mean, look: These chemicals are everywhere-in our soil, in our water. It's going to take a very long time to clear them out. And we probably won't see the positive effects in our lifetimes.