Human hormones, chemicals a bad mix

First organic food -- free of pesticides -- had the spotlight. Then consumers learned about buying cosmetics without parabens. Just last month Minnesota banned the chemical Bisphenol-A (BPA) from baby bottles and sippy cups.

The mounting health cautions might seem tedious -- does every little thing cause cancer? -- but a common thread weaves through the concerns. Numerous everyday products are made with chemicals that may disrupt people's endocrine system, which is also known as the hormone system.

A quick primer: The endocrine system is responsible for brain and nervous system development, reproduction, metabolism and blood sugar. Hormones, including estrogen and testosterone, are like messengers moving through the body, telling receptors on cells what to do.

The problem is that many chemicals -- called endocrine disruptors -- mimic hormones. They attach to receptors and cause cell division, altered gene expression and other harmful changes.

Chemicals enter the body and environment in many ways. Ingredients in lotion and lipstick seep into the skin and bloodstream. Pesticides, food additives and chemicals in packaging make their way in when people eat. Weedkillers and fertilizer sprayed on lawns end up in waterways.

Endocrine disruptors have been blamed for playing a role in attention deficit hyperactivity disorder (ADHD), autism, cancer, diabetes, earlier puberty, immune problems, obesity and infertility.

"I think everyone is a little stunned that we have all these chemicals in the environment that have the potential to cause harm," said Deborah Swackhamer, an environmental health professor at the University of Minnesota. "Hormones at very small doses regulate just about everything, and if you've got chemicals that can mimic that, they can mess with growth, behavior and development."

Environmental estrogens are one of the most common endocrine disruptors. Birth control pills, BPA and metals that leak from old cell phones and batteries are all considered environmental estrogens. Suzanne Snedeker, associate director of Cornell University's Program on Breast Cancer and Environmental Risk Factors, said that although exposure levels can be very low in many consumer products, cumulative and combined effects may increase breast cancer risk. Estrogen exposure signals cells to divide and aids breast tumor growth, she said.

Researchers at the National Institute of Environmental Health Sciences (NIEHS), a part of the National Institutes of Health, found that when mice were exposed to the chemical DES, their grandchildren were more likely to develop tumors.

"A growing body of evidence suggests that numerous chemicals, both natural and manmade, may interfere with the endocrine system and produce adverse effects in humans, wildlife, fish or birds," states an NIEHS document.

DDT, DES, PCBs, dioxin and some pesticides are undisputed human endocrine disruptors. But when it comes to many other chemicals, proving effects on human is slow or difficult. There are questions about how to translate wildlife and animal research to humans, what exposure level is acceptable and who should pay for reducing these chemicals.

Time for reform

Also, the EPA said the Toxic Substances Control Act (TSCA) of 1976 created "high legal and procedural hurdles" that make it "difficult [...] to limit or ban chemicals found to cause unreasonable risks to human health or the environment." The EPA added that their new administrator, Lisa Jackson, indicated chemical management is one of her top five priorities and that there's "a growing consensus that the time has come for TSCA reform."

According to the FDA, there hasn't been sufficient data to show that more restrictions are needed.

Although some agencies and government scientists are pushing forward, "there is sort of a lag," said Renee Sharp, director of the Environmental Working Group's California office. Sharp said government regulators can get so caught up in scientific footnotes that they miss the larger picture and fail to move forward.

For example, when studies on BPA came out nearly a decade ago, Japan swiftly removed it from food and soda can lining, and the European Union and Canada have also restricted its use. Higher BPA concentration in urine was linked to greater risk for cardiovascular problems and diabetes, according to a study published last fall in the Journal of the American Medical Association.

But the FDA still hasn't restricted use of the chemical. Theo Colborn, an environmental health analyst and founder of the nonprofit Endocrine Disruption Exchange, blames that partly on recent decisionmakers at the FDA and EPA, who she said were more interested in protecting industries. "[Regulation] threatens the bottom line at many corporations," she said.

Calls to the American Chemistry Council, which represents many of the companies that manufacture or sell products with suspected endocrine disrupting chemicals, were not returned.

Consumers will drive change

Many people say protections are coming. "I think we can expect to see that chemicals will be evaluated differently moving forward," said Linda Birnbaum, director of the NIEHS and the National Toxicology Program. "There are many chemicals we haven't yet asked the question [of whether they might disrupt the endocrine system]."

And consumers today are more deliberate with purchases, Swackhamer said. "I'm very impressed with people's awareness and knowledge and concern," she said.

"I would encourage people to get as educated as possible and let their views be known," she said. "Our elected officials and regulators are very interested in doing the right thing here -- they need to hear from people about what they want."