Industrial Chemicals Lurking In Your Bloodstream

Posted on Jan 31, 2010 in Uncategorized

Rebecca Ruiz, 01.21.10, 04:00 PM EST

Everyone has heard about BPA. How many other potentially nasty chemicals may be in your body?


Concern is heating up over whether common industrial chemicals found in plastics and other consumer goods could be harming our kids.

The Food and Drug Administration made headlines when it said last week that it would review the safety of Bisphenol A, an industrial chemical commonly used in plastic bottles and food containers. It is worried that the chemical might have subtle but deleterious effects on the neurological and reproductive development of kids.

For years the chemical has been the subject of controversy over whether it can harm people. Some studies have linked it to abnormal brain and reproductive organ development in animals while others have shown little evidence that is harmful in the small doses that are likely to be ingested by humans. Other adverse health effects to which it has been linked include erectile dysfunction and heart disease in humans and early onset of puberty in female rats.

In Depth: 10 Chemicals You Should Worry About

But BPA is just one of hundreds of industrial chemicals that may be in your blood or urine right now. A report released by the Centers for Disease Control and Prevention in 2009 found detectable levels of a total of 212 chemicals in blood or urine samples from 2,400 people nationwide. These included the agricultural pesticide atrazine, the gas additive Methyl tert-butyl ether (MTBE) and the coal and petroleum byproduct benzene. Little is known about the human health effects of most of the chemicals.

The chemical industry has long argued that these chemicals are safe at current exposure levels. None have been conclusively shown to harm humans at low levels. But R. Thomas Zoeller, an endocrinologist and University of Massachusetts professor, says the widespread presence of industrial chemicals in the human population is alarming. “I sincerely hope that what we know from animal research doesn’t translate to humans, but I don’t have much optimism,” he says. Worse yet, he adds, “You’re not giving people a choice about contamination.”

Researchers are particularly nervous about the weed killer atrazine, BPA and other chemicals known as endocrine disruptors. These are thought to interfere with the body’s ability to regulate estrogen or other hormones. When those processes go awry, it can lead to neurological and reproductive defects. Endocrinologists are concerned that these chemicals may be able to cause subtle health problems at doses far lower than the high doses toxicologists typically use to assess safety today.

A widely cited study published in the Proceeding of the National Academy of Sciences in 2002 found that atrazine exposure at doses 30 times lower than allowed by the EPA caused tadpoles to develop both male and female sex characteristics, turning them into hermaphrodites. It also lowered testosterone levels in adult male frogs below the level found in females.

The EPA is evaluating the human health effects of atrazine and is expected to publish some of its results late this year. That’s not the only endocrine disrupting chemical that the EPA is worried about. Late last year, the agency quietly said that it would review the safety of phthalates, long-chain perfluorinated chemicals (PFCs), polybrominated diphenyl ethers (PBDEs) and short-chain chlorinated paraffins. The chemicals are found in a range of commercial and consumer products–building materials, semiconductors, furniture, toys and cosmetics–and tend to accumulate in the environment or in animal and human tissue. More than 1 million pounds of each is produced annually.

Cal Dooley, president and CEO of the industry group American Chemistry Council, says the industry has the “utmost confidence” in the safety of these chemicals and questions the EPA’s decision to single out a few chemicals.

U Mass’ Zoeller says the EPA’s decision to single out the four chemicals is sound, but he is also worried that outdated methods will be used during the EPA’s review. In the past, researchers have studied endocrine disruptors the same way they studied other potentially toxic chemicals: by giving animals ultra high doses and watching for toxic effects. But paradoxically, his research has shown that endocrine disruptors may cause the most harm at relatively low doses. Low doses of the chemical may mimic or disrupt the effects of natural hormones that have potent effects in small amounts. High doses, on the other hand, tend to desensitize the endocrine system, he says.

In addition to reviewing the safety of industrial chemicals, the EPA is also looking to reform decades-old toxic chemical legislation known as the Toxic Substances Control Act of 1976. Among its goals is to require manufacturers to release safety data, which they can currently protect as confidential information.

There are now 86,000 chemicals on the EPA’s inventory of compounds used in commercial and consumer products. Since 1976, the agency has only succeeded five times in restricting or banning chemicals.

“We feel that we need to be able to say with confidence that chemicals sold in the U.S. are safe,” says Jim Jones, deputy assistant administrator for the EPA’s office of pesticides and toxic substances. “We have a lot of work to do to get there.”

As for BPA, study results have been confusing as to whether or not it really harms people. Last week, for example, an epidemiology study in PLoS One found that people with high levels of BPA had a slightly increased risk of heart disease. A similar study conducted in 2008 by the same authors found a much stronger correlation.

During the Bush administration, the FDA deemed BPA safe at low levels. But citing new research on the chemical’s potential effects on neurological and reproductive organ development in infants and children, the FDA now says it will take steps to reduce BPA exposure in the food supply. Its BPA safety review won’t be finished until at least 2012, when two government studies on BPA are scheduled to finish.