The Center for the Environment's 25th Anniversary newsletter has been released and is available for…
04/25/13 by Juanita Teschner
Dr. Pete Myers: ‘Science on Endocrine Disruption Offers Opportunity to Improve Public Health’
Dr. Pete Myers, a noted scientist involved in primary research on the impacts of endocrine disruption on human health, spoke April 9 at the Center for the Environment facility on the Catawba College campus in Salisbury. The founder, CEO and chief scientist of Environmental Health Sciences, he co-authored Our Stolen Future, a book about how contamination threatens fetal development. Juanita Teschner, the Center’s director of communications, talked with Myers after his visit to the Center. This is an edited transcript of that conversation.
Q: How did you get interested in research on endocrine disruption?
A:I was doing research on a species of bird that was undergoing a population collapse. It focused on whether chemicals [that accumulated in their bodies] would interfere with migratory orientation. As I began to read about the insidious nature of chemical interference with developing animals, I realized, “Wait a second. People are animals, too.” And I began to become very interested in the human implications. That was almost 30 years ago. I gradually shifted my focus from bird biology to human biology.
Q: What are endocrine disruptors?
A: There are about 800 substances that have been shown to interfere with hormone action. They include pesticides – herbicides, insecticides and fungicides. Another type is industrial chemicals that are used to make things, like bisphenol A (BPA) and phthalate.
I began to read that these compounds wind up in consumer products, but they don’t stay in them. For example, the polybrominated diphenyl ethers are used as flame retardants in things like the foam in furniture. When the foam decays, it becomes dust on floors, and children crawling around pick it up on their hands and then put their hands in their mouths. You find young children with higher levels of polybrominated diphenyl ethers than their parents.
Q: What are some of the health problems that arise with exposure to these chemicals?
A: Learning disabilities, breast cancer, infertility. The list is very long.
The strength of the science for any given one of those adverse end points varies. For some it’s plausible but we have a long way to go. For others, it’s getting much closer to being certain. The dark horse in this race that now pretty much leads the pack is obesity. A famous photo I showed at the lecture, which was taken by a scientist at the National Institute of Environmental Health Sciences, reveals the consequences of early life exposure to a chemical that turns on a gene that makes stem cells become fat cells.
Q: What chemical does this?
A: Several different types of chemicals. The term now is to call them “obesogens,” contaminants that increase the risk of obesity. Some of the exposures are fungicides used in produce. Bisphenol A is an obesogen, widely used both to make plastic and also used as a developer in thermal paper – the type of paper that comes out of your receipt machine when you go to the ATM or when you get gas or get one of those flimsy tickets at the airline counter.
Q: What can we do about this?
A: What we have to do is help chemists ask questions early in the design process before anyone gets commercially committed to a product…help them ask, “Is this likely to be an endocrine disruptor?” Actually about 30 of the world’s leading scientists in chemistry and endocrine disruption science are doing just that. If you go to tipedinfo.org, you can find a description of what we’ve been doing to help chemists and companies make money by avoiding endocrine disruptions through design. It’s not a regulatory process. It’s a voluntary science-based process designed to reflect current scientific understanding, and we think it has great commercial promise.
Q: What concentrations are harmful?
A: It varies from compound to compound. Here’s the big problem we face: The impacts don’t just increase or decrease with the dose. They often change completely. They’re like hormones. Different things happen at different doses with endocrine disruption compounds.
What that does is throw a huge challenge to the core assumption of regulatory toxicology, which is the basis for all the standards that have been set for 100 years or more. Those standards are set with the assumption that high-dose testing can reveal all the results that might happen at low doses. And that’s not the case. For example, obesogens can cause morbid obesity at really low doses but weight loss at high doses. Nicholas Kristof, a columnist for the New York Times, wrote a column on January 20 called “Warnings from a Flabby Mouse” that explains this: http://www.nytimes.com/2013/01/20/opinion/sunday/kristof-warnings-from-a-flabby-mouse.html?ref=nicholasdkristof&_r=0
It wasn’t until people began to realize that some contaminants behave like hormones and then asked if that meant that some contaminants have different effects at different doses that this became an issue.
My colleagues and I published a massive review of this a year ago in “Endocrine Reviews,” the leading journal of endocrinology, which sparked an international discussion.
The National Institute of Environmental Health Sciences and its counterparts in Denmark, France, Germany and the European Commission brought together 200 scientists and regulators in Berlin to talk about this. At the meeting the French counterpart to the U.S. Federal Drug Administration (FDA) presented an independent assessment that agreed with our paper, and just last week the Danish Ministry of the Environment sent a report to the European Commission also basically agreeing with our paper. This has forced the U.S. Environmental Protection Agency (EPA) to conduct an extensive review that is now under way.
Q: What happens if the EPA finds out that your research is correct?
A: If we are right, and we are, it’s going to mean hundreds of safety standards have to be revised. They have to be strengthened by not a factor of 10, not a factor of 100, but a factor of 1,000 or more. And it’s going to mean that some products come off the market.
Q: Who is most vulnerable to endocrine disruption?
A: The fetus is by far the most vulnerable for a number of reasons. Its metabolic defenses, which would detoxify these compounds, haven’t developed yet. Its organs are also still developing so there are things under way that can be disrupted at those crucial windows that you have already passed as an adult.
The older you get, the less vulnerable you are, but you’re not invulnerable. For example, a woman’s breast tissue has several windows of vulnerability. Puberty and preparing for breast feeding reopen that window of vulnerability to potential damage.
Q: What are some of the health problems adults face that had their origin in the womb?
A: Obesity is one. Metabolic disorders and heart disease clearly are set in motion very early in life. There are classic epidemiological studies, for example, that show that certain nutritional deprivation during fetal life dramatically increases your risk of heart disease later in life. If you’re in the womb during times of deprivation, physiologically you’re preparing yourself for deprivation throughout life. But if, as an adult, you get lots of calories, your body isn’t prepared to deal with it and you are very prone to heart disease and Type II diabetes.
Breast cancer is another. A Kaiser Permanente study showed that if you are exposed to DDT before puberty, you’re five times more likely to develop breast cancer by the age of 50 than if you haven’t been exposed. But if you’re exposed after puberty, there’s no difference.
Q: What can we do individually and corporately to decrease these health risks?
A: Let me recommend a really great book: Slow Death by Rubber Duck. It’s a little flippant but it’s good. It’s about an experiment done by two guys who locked themselves in an apartment and changed their lifestyles. In one phase they tried to maximize their exposures and in another they tried to minimize them. Tests showed these lifestyle changes had a dramatic effect on the number of compounds that got into their bodies.
So there are individual lifestyle choices that make a difference, but it’s not fair to force a mother to be a chemical engineer to go shopping for her kids. So we also need a policy response to use the science to decrease exposures.
The good news is that when our country and other countries set their minds to reduce the exposures to things like lead, we were very successful. We acted upon our knowledge and got the response we needed so lead levels are now 2-3 percent of what they were when I was growing up. We can do the same thing here.
Q: What kind of lifestyle choices have you made to minimize contaminants in your body?
A: Well, first of all everything is about moderation. You don’t have to go cold turkey on anything. I shifted my diet to be lower in the food chain – more toward fruits and vegetables. I stopped microwaving in plastic. I did go cold turkey on that. I tested my drinking water. I have a well and I know it’s safe. I stopped eating canned foods, to the extent that I could. The reason I did that is that 80 percent of cans on U.S. markets today are lined with a resin that is made out of bisphenol A. It leaches into the food in the can. I also minimize my interaction with paper receipts.
Our book Our Stolen Future has a chapter called “Protecting Ourselves” that includes recommendations that are just as valid today as when we wrote it 20 years ago. There are also some great websites: Environmental Working Group – ewg.org – and our website, Environmental Health News – ehn.org.
Q: Is there anything else you would like to add that you think would be critical for people to know?
A: I just want people to realize that we have the opportunity to change this by making regulations and commerce reflect where science is today. I see a really big opportunity to protect public health, and I see huge savings in health care costs ahead of us by acting on this science and lowering these burdens. That’s really good news.