Disruptive CHEMICALS

In 2009, DelMonte canned green beans made headlines when Consumer Reports revealed they were among 18 other products found to contain the industrial chemical bisphenol-A (BPA) at levels known to be harmful to animals. A media brouhaha ensued, sparking renewed interest among consumers about what might be in their food that is not on the label.

Bisphenol-A is one of thousands of chemicals and compounds known as endocrine disruptors because of their potential to interfere with hormone action in animals and humans. These chemicals are used in everything from food cans and plastic water bottles to steering wheels and furniture. As the government sorts through the research to determine the fate of plastics containing endocrine disruptors, consumers are left to fend for themselves.

“Trying to avoid these chemicals is like trying to avoid breathing,” says R. Thomas Zoeller, PhD, professor of biology at the University of Massachusetts at Amherst. “They’re tough to pin down because manufacturers are not required to divulge what is in their plastics. Right now, industry is protected because they say that information is proprietary.”

However, a familiarity with the most common endocrine disruptors and the products that often contain them can help consumers make better choices, he says.

BISPHENOL-A

Bisphenol-A mimics estrogen in the body. Animal studies suggest an association between BPA and obesity, diabetes, heart disease, immune dysfunction, and changes in reproductive organs. In 2008, the National Toxicology Program of the U.S. Department of Health and Human Services published a monograph expressing “some concern for effects on the brain, behavior, and prostate gland in fetuses, infants, and children at current human exposures to bisphenol-A.”

Derived from petroleum, BPA is used in food packaging, plastic bottles, dental sealants, thermal paper used for cash register receipts, and other products. Approximately 6.4 billion pounds of BPA are produced throughout the world each year, and it’s detectable in 90 percent of the population.

Buying products that are labeled BPA-free may help, but those products may contain bisphenol-S (BPS), an alternative that may be just as harmful, says Tracey Woodruff, PhD, MPH, professor and director of the Program on Reproductive Health and the Environment at the University of California–San Francisco.

“There hasn’t been much testing for BPS, but what studies there are suggest that it, too, has endocrine-disturbing properties,” Woodruff says. She adds that plastics manufacturers have thousands of alternatives from which to choose. “If they take out BPA, they’ll just use the next thing on the shelf that may or may not have potential effects. No one is really sure what they’re using in ‘BPA-free’ bottles.”

Although it may seem hopeless to try to eliminate exposure to BPA, there are a few ways consumers can cut their exposure to it and other members of the bisphenol family, says Theo Colborn, PhD, president of the Endocrine Disruptor Exchange in Paonia, Colorado, and professor emeritus at the University of Florida–Gainesville. “Go back to buying foods in their raw state, and avoid buying products that are packaged. Shop the perimeter of the grocery store.”

Frederick vom Saal, PhD, Curators’ professor in the Division of Biological Sciences at the University of Missouri, notes that if consumers must use plastic containers, it is best to wash them issue of Environmental Research by Shanna Swan, PhD, of the University of Rochester’s Department of Obstetrics and Gynecology, summarized the health outcomes associated with prenatal exposure to phthalates, such as asthma, eczema, and, in baby boys, partially descended testes. Th e review also noted low sperm count, DNA damage in sperm, decreased sperm motility, increased insulin resistance, and decreased levels of thyroid hormones in men.

Although it is nearly impossible to avoid exposure to phthalates from car interiors or hospital equipment, consumers would be wise to do their homework regarding personal care products, says Zoeller. “Anything you apply to your body is a drug delivery tool. Phthalates are fat soluble, and when you rub them on your skin, they will be absorbed.” Zoeller recommends visiting the Environmental Working Group’s website (ewg.org), which contains a database of cosmetics and guides to various consumer products. He uses GoodGuide, a smartphone application that provides product ratings for health, environmental friendliness, and social responsibility when users scan in UPC symbols. Developed in part by Dara O’Rourke, PhD, associate professor in the Department of Environmental Science, Policy, and Management at the University of California–Berkeley, GoodGuide relies on research and other parameters to rank the products. Visitors to the website (goodguide.com) may search the product database as well.

Finally, vom Saal suggests avoiding plastics with recycling codes 3 and 7, which are more likely to contain BPA or phthalates.

PHTHALATES

Phthalates are nearly as common as BPA. Th ey’re used in personal care products such as nail polish, deodorant, lotion, and shampoo; home décor such as flooring and shower curtains; insect repellant; hospital equipment such as tubing and IV bags; and car dashboards, steering wheels, and gearshifts.

Phthalates are anti-androgenic, meaning they work against androgens, male hormones. A literature review published in the October 2008 issue of Environmental Research by Shanna Swan, PhD, of the University of Rochester’s Department of Obstetrics and Gynecology, summarized the health outcomes associated with prenatal exposure to phthalates, such as asthma, eczema, and, in baby boys, partially descended testes. Th e review also noted low sperm count, DNA damage in sperm, decreased sperm motility, increased insulin resistance, and decreased levels of thyroid hormones in men. Although it is nearly impossible to avoid exposure to phthalates from car interiors or hospital equipment, consumers would be wise to do their homework regarding personal care products, says Zoeller. “Anything you apply to your body is a drug delivery tool. Phthalates are fat soluble, and when you rub them on your skin, they will be absorbed.”

Zoeller recommends visiting the Environmental Working Group’s website (ewg.org), which contains a database of cosmetics and guides to various consumer products. He uses GoodGuide, a smartphone application that provides product ratings for health, environmental friendliness, and social responsibility when users by hand and to avoid using them in the microwave. “Heat breaks the bond that links BPA and polycarbonate, which frees the BPA to wreak havoc.”

POLYBROMINATED DIPHENYL ETHERS (PBDES)

Polybrominated diphenyl ethers (PBDEs) are used as fl ame retardants in electronics, carpets, upholstery, and foam furniture. As these products age and break down, PBDEs enter the environment via dust, where they are inhaled or ingested. A study published by researchers at the University of California–Berkeley in the November 15, 2012, issue of Environmental Health Perspectives, suggests an association between prenatal and childhood exposure to PBDEs and poorer attention, decreased fine motor coordination, and lower IQ in children.

“Flame retardants, namely PBDEs, are a hot topic because they are so widespread,” says Woodruff. She likens their pervasiveness to that of polychlorinated biphenyls (PCBs), which were used in paints, plastics, rubber products, and industrial equipment until they were banned in the U.S. in 1979 for health and environmental reasons.

“There are indications that PBDEs, like PCBs, will hang around in the body for 20 years,” Woodruff says. “Now there is compelling evidence that they affect neurocognitive development. The effect on IQ is comparable to exposure to lead.”

REGULATORY LIMBO

That endocrine disruptors are so common begs the question: What is the government doing about them?

The Environmental Protection Agency (EPA) launched the Endocrine Disruptor Screening Program in 1996, and the National Center for Toxicological Research at the Food and Drug Administration (FDA) maintains the Endocrine Disruptor Knowledge Base as a resource to help scientists develop computational predictive toxicology models as alternatives to animal testing, which is both expensive and timeconsuming.

Yet despite the collective knowledge of researchers in both academia and government suggesting that many of these chemicals are more harmful than previously thought, the wheels of federal regulation turn slowly. For example, Canada banned BPA in baby bottles in 2007; the FDA did the same five years later, in July 2012—well after 11 states had already banned the substance in those proucts. This, after the agency declared in March 2012 that it found no convincing evidence to support the belief that BPA is a hazard to humans, and that it will continue to allow use of BPA in cans and other food packaging.

Some researchers feel they are waging an uphill battle. “We’ve been jousting with the FDA over their risk assessment process for years,” says vom Saal, referring to scientists and endocrinologists across the field of endocrine disruptor research.

Vom Saal says that the FDA’s methods assume that the effect of these chemicals depends on the dose, an approach that he says current research proves is outdated. Along with Zoeller, Colborn, and others, he co-authored a 78-page literature review published in the June 2012 issue of Endocrine Reviews that describes how low doses of endocrine disruptors may cause a disproportionate amount of harm compared to high doses.

“Over the past 60 years, [the field has] amassed enough knowledge that anyone who studies hormones knows that receptors are more sensitive to low doses, and that at high doses, you shut the cells’ response system down,” vom Saal says.

“The FDA’s approach is a century out of date, like using iron lung technology to treat polio.”

In the September 2012 issue of Endocrinology, the Endocrine Society published a position statement asserting that the age when exposure occurs matters: Developing fetuses, infants, and children are especially vulnerable. The position statement, written by Zoeller, Woodruff, vom Saal, and others, summarizes the Society’s suggestions for strengthening the EPA’s Endocrine Disruptor Screening Program.

“What we were warned about before with endocrine disruptors pertained to much higher levels. Now we know that much lower levels can have bad effects,” says Colburn. “We could go on collecting evidence for another 10 years, but when you get right down to it, the laws need to be changed.”

—D’Arrigo is a health and science writer based in Holbrook, New York, and a regular contributor to Endocrine News.

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