Pete Myers is a founder, CEO, and chief scientist of Environmental Health Sciences, a nonprofit that increases public understanding of emerging scientific links between environmental contaminants and human health. Myers also is a co-author of Our Stolen Future, a groundbreaking book that sounded the alarm on the effects of endocrine disrupting chemicals on health and development. In the decade since the book’s publication, mounting scientific evidence has further supported the authors’ warnings that industrial chemicals interfere with key biological processes, leading to disease and disability. Myers spoke with Kim Ridley about current research, controversies, and reasons for hope. 
Kim Ridley: Our Stolen Future revealed that some synthetic chemicals interfere with our body’s hormones. What are the consequences?
Pete Myers: Hormones are part of the control mechanism for how genes behave, so when you alter hormone function, you alter gene behavior. You make it so genes can’t be turned on or they can’t be turned off, and that leads to health problems. What we’ve learned in the last 20 years of research is that some synthetic chemicals inadvertently interfere with our body’s natural chemical messengers. And we’re seeing effects on fertility, on how the brain works, and on disease resistance.
We’re now learning that chemical signals that reach the fetus during development can have lifelong effects on health. Hormones are natural chemical signals. Synthetic contaminants can mimic or block them. For example, it’s now pretty clear that testicular cancer, which is a disease of young men in their second, third, and fourth decades of life, is caused by errors in fetal development that lie quiescent for decades and then grow into malignant cancers. There’s an emerging realization that errors like this in fetal development can have lifelong consequences, and that some contaminants that we’ve invented are capable of interfering with the control mechanisms guiding genes during development at low levels of exposure.
We also have strong evidence from a combination of animal data and human data linking contaminants that are interfering with gene expression to infertility issues and to brain functioning, for example there’s lots of evidence now on ADHD. It’s also pretty clear that fetal development of the immune system is leading in some cases to hypersensitive immune systems, and in other cases to insensitivity of the immune system, meaning that you become vulnerable to pathogens that you could have resisted.
Kim Ridley: One of the most controversial chemicals is bisphenol-a. What are the concerns?
Pete Myers: Bisphenol-a, or BPA, is the poster child for low-level effects of contaminants. It was invented in the late 1800s and discovered in the 1930s to be a synthetic estrogen. Since the 1950s, BPA has been used to make polycarbonate plastic, which is now ubiquitous. BPA is used in hard plastic water bottles, food can linings, dental sealants, and some carbonless paper, such as ATM receipts. It can leach out of these materials and into our bodies.
About 95 percent of people in the U.S. have detectable amounts of BPA in their bodies. Twenty years ago a toxicologist would have said the levels are too low to cause health effects. But in the last 10 years, the science looking at how BPA works has exploded with new information telling us that it can affect important cellular processes down to .23 parts per trillion. We now have many examples of studies showing effects in animals at levels to which most people are exposed.
Kim Ridley: What kinds of effects?
Pete Myers: BPA interacts with the hormone system in at extremely low levels of exposure. We know that this compound alters the behavior of over 200 genes—that’s one percent of the human genome at a minimum, and that’s not good. And these genes are centrally involved in how your brain grows, how your reproductive tract is formed, and how your body metabolizes insulin.
The most striking result came out this year. If you expose adult mice to a level of BPA found in 95 percent of Americans, the mice will develop insulin resistance in four days. Insulin resistance is a key part of what’s called metabolic syndrome, a collection of disorders that includes obesity and type II diabetes—25 percent of people who develop insulin resistance go on to develop type II diabetes.
We don’t have the human epidemiology to prove a connection between BPA and diabetes, but we do have some interesting evidence from these animal studies. We know that BPA has become ubiquitous over the last two decades and obesity and type II diabetes have skyrocketed over this same time period. We also know that female mice exposed to low levels of BPA in the womb can become obese in adulthood.
Kim Ridley: You say that trace amounts of BPA and other chemical contaminants may actually “hijack” genes during development. What happens?
Pete Myers: Think about what happened on 9/11. A small number of guys seized control of the steering mechanisms of those planes and took them on a path they never would have taken. That’s what can happen with gene hijacking. Low levels of chemical contaminants enter the body and either shut genes down when they should be on or turn them on when they should be off, shifting the course of development. Even a small change during fetal development can have huge consequences over a lifetime of 70 years.
There’s some astounding work underway right now with BPA and a number of compounds that alter how genes are set up in the fetus to affect the feedback system controlling weight throughout life. We all know tall, thin people who can eat like a horse and never gain weight. And there are other people who diet but can’t lose weight. That has to do with the feedback mechanisms that control our weight. BPA and other chemical contaminants may be affecting hormonal signals in the womb that determine our weight set points just like a thermostat is set to control your house’s furnace.
Gene hijacking might also underlie certain kinds of cancer. A developing fetus gets not only two arms and ten fingers, but also the right number of hormone receptors. The number of hormone receptors in your breast tissue determines how sensitive you are to hormonal stimulation when you’re an adult. If you get too many hormone receptors because of a chemical signal that shouldn’t have been there, you may develop breast tissue that’s hypersensitive to something that a normal person wouldn’t have a problem with. That’s the nature of the low-level effect.
Research by Dr. Ana Soto and Dr. Carlos Sonnenschein at Tufts University recently found that exposure to tiny amounts of BPA—less than parts per billion—in the womb has profound effects on mammary duct development in mice. You wind up with an adult mouse with a mammary duct structure that in humans would indicate a risk for breast cancer.
Kim Ridley: How does gene hijacking challenge current thinking about genetic diseases?
Pete Myers: Most people think about genes as what we get from our parents. Either we got the good gene or the bad gene, and that’s the end of the story. If we get the good one we’re golden, and if we get the bad one, well, who says life is fair? But what they don’t realize, for example, is that most people who get breast cancer don’t have the mutant gene. They have the good gene, but something has turned it off and is suppressing its protective behavior. We know that BPA and some other environmental contaminants are capable of doing that, but we don’t yet have the epidemiological links.
Kim Ridley: You write that this generation of children could grow up to be less healthy than their parents—a first in modern history—due to new epidemics of diseases that may be linked with the effects of chemical contaminants on gene expression during development. What are you seeing that worries you the most?
Pete Myers: We’re creating a generation of kids who are heading towards a difficult adulthood because of metabolic disorder, which is the combination of obesity, type II diabetes and insulin resistance. And then there are related problems like the risk of heart disease and high blood pressure. This isn’t just a U.S. problem, it’s a global problem. Childhood obesity has become rampant worldwide. I recently read that car seats are being redesigned because too many kids can’t fit into them—and it’s not because they’re getting taller.
There are two other epidemics that may be linked with the effects of synthetic chemicals on gene expression, although the evidence is a little less rigorous. One is the rash of epidemics of neurocognitive problems like ADHD and autism. I’m going to go out on a limb here, but colleges are increasingly finding it difficult to achieve a balanced sex ratio. It’s harder and harder to find guys who are competitive with girls in college. Animal experiments have found that male fetuses are more susceptible than females to some synthetic chemicals that affect neurocognitive development. My bet is that this is part of the puzzle.
The third epidemic is infertility, and the statistic that grabbed me most recently is that the rate of infertility is increasing most rapidly in women under the age of 20. There also appear to be some very big changes in sperm count in young men. For example, 40 percent of Danish military recruits have sperm counts that are beneath the threshold where science would expect to see decreases in the likelihood of successful fertilization. 
We’ve known for a long time that high-level exposures to certain metals and pesticides can decrease fertility. Now we have strong animal evidence that some contaminants can hijack genes during fetal development that are important to fertility in adulthood. To confirm this in people is very hard: it takes precise measurements of fetal exposure and estimates of adult fertility of the same person who was exposed in the womb. One way scientists are solving this challenge is by finding old tissue and fluids that have been frozen for decades. One beautiful study along this line found that women whose umbilical cord blood revealed they had been exposed in the womb to DDT had more difficulty getting pregnant when they were adults.
Kim Ridley: Despite the growing evidence, there’s still a lot of controversy about the effects of some of these chemicals. When I did an Internet search on BPA, the first thing that came up was a web site refuting harmful effects. What’s creating this confusion?
Pete Myers: Money. Six billion pounds of BPA were produced last year. It’s a very valuable product to the companies that make it. They are up to the same tricks that the tobacco industry used to refute the impact of smoking on health. It took decades to get beyond that trickery, and with tobacco, the science is relatively simple.
The current federal standards for BPA are based on experiments in the early 1980s that showed that high levels of exposure cause weight loss in rodents. They never tested low enough to find a level at which they saw no effect, but simply assumed that if they added a safety factor, it would be okay. Now we’re seeing animal experiments showing profound consequences way beneath that level of exposure. And the FDA and EPA under the current administration have been unwilling to reassess their standard.
There have been well over 100 animal studies in the last 5 years show strong effects at low doses. Over 90 percent of the studies funded by government and carried out by university scientists find adverse effects. Eleven have been done or funded by industry. Of those, none find effects. The odds of this happening by chance are fewer than 1 in 2 billion.
Kim Ridley: How do we evaluate the risks in terms of our own health?
Pete Myers: It all depends upon how concerned you are about these things and what risks you want to take. There are also effects of BPA that appear to increase the aggressiveness of prostate tumors. I worry about that because that’s my age group, so I’m eliminating canned food from my diet. I looked at the science, and although it’s not certain, it’s a reasonable precautionary step for me to take.
Kim Ridley: What steps can we take to reduce exposure to suspect chemicals?
Pete Myers: There are some simple things you can do like eating low on the food chain and keeping hot plastic away from hot food. Also, know the quality of your water, and don’t assume that bottled water is better. Understand that lead paint is a legacy of the 20th century and it’s in houses throughout the country. Know about lead in your house. It doesn’t affect just poor people, and it causes devastating effects in children.
Kim Ridley: Are there collective actions we can join?
Pete Myers: One immediate step is to write your members of Congress to support the National Children’s Study, which has been planned to examine environmental influences on children’s health and development from before birth to age 21. President Bush zeroed this study out of the 2007 budget, but there’s an effort under way to try to reinstate it.
There are environmental health policy initiatives under way at the state, local, and national levels. A good place to find out what’s happening in your area is the Collaborative for Health and the Environment. The collaborative is informative, very careful with the science, and facilitates learning about policy initiatives.
Kim Ridley: Is it possible to reclaim our stolen future?
Pete Myers: Absolutely. Is it going to be easy in all cases? No. We have political obstacles and economic obstacles. The good thing about this is there are some interventions that we can implement. We dramatically decreased lead levels and we then benefited hugely. With a lot less lead, we have many fewer kids who are lead poisoned. That translates to IQ points, and economists who have analyzed this say that it has brought millions of dollars back into the economy, according to the Centers for Disease Control.
BPA is much less persistent than lead. It lasts in your body about eight days. We can get it out of our bodies if we take action.
Another bright sign is the developing field of green chemistry. Chemists are beginning to create molecules that are safe by design. At the same time, companies are realizing that parents don’t want to buy a plastic bottle made out of synthetic estrogen and heat milk in it. They want something that’s safe, so markets are being created. People are going to make money by responding to these signals.
Kim Ridley: Given the challenges, what sustains your hope?
Pete Myers: It’s really depressing to realize that we’ve brought things into commerce and into our homes that are making us sick. But the good news is that science is identifying a lot of diseases that we had no clue might be caused by environmental factors. This science is telling us that we can prevent diseases that two decades ago we didn’t know were preventable.
We used to think that all genetic diseases were hereditary. Now we know that some of them are caused by chemical contaminants that influence a gene’s behavior. Once we understand what’s causing these diseases, we can prevent them. We can move away from a culture of treatment and care to a culture of prevention.
