Flame retardants were in the proverbial hot seat this week as several studies confirmed not only their presence in pregnant women and children, but also their disruptive behaviors to a child's development.

The main study that has everyone talking reported that high levels of brominated flame retardants can alter pregnant women’s thyroid hormones, which are critical to a baby’s growth and brain development. The study, published in Environmental Health Perspectives, is the first human research showing a link between the ubiquitous chemicals and altered levels of the hormones in pregnant women.

What are flame retardants? The chemicals, polybrominated diphenyl ethers, or PBDEs, are widely found in furniture cushions, carpet pads, electronics and other common household items. They are sprayed on these items to minimize the chance the item will catch on fire. That sounds like a good thing at first until you realize that these chemicals don't simply stay on the products.  

Most exposure to the flame retardants comes from household dust, but food also is a major source. The chemicals are slow to break down and build up in fatty tissues, so they accumulate in fish, meat and other foods. We are just beginning to understand the effect these chemicals have once they are inside the human body. In January, a study in California found that women exposed to high levels of flame retardants take substantially longer to get pregnant than women with low levels. The chemicals have been detected in about 97 percent of people tested in the United States.

So back to the most recent study in the news this week. Researchers in Berkeley, Calif., tested the blood of 270 pregnant women in California’s Salinas Valley. The study is part of a larger project monitoring the health of pregnant women and children in the valley, which is predominantly a low-income, Mexican-American farm community. They found that the women’s thyroid-stimulating hormone, or TSH, declined almost 17 percent for every tenfold increase in PBDEs. Low TSH suggests that the thyroid is producing too much hormone on its own. The reductions were found for every type of PBDE tested.

In other words, the more flame retardants a pregnant women was exposed to, the more out of wack her thyroid hormones were. Of course, researchers don't know yet exactly what effects, if any, this will have the pregnant women's babies, but some researchers say it may lead to smaller fetuses, and reduce children's intelligence and motor skills.  

Several recent studies have reported a link between children's mental skills and the flame retardants. One study, conducted at Columbia University, founds that New York City mothers with higher PBDE levels had children who scored lower on tests of mental and physical development. A Dutch study produced similar results — children had reduced fine motor skills, lower IQs and more attention problems if their mothers were exposed to higher PBDEs. 

This is a bit daunting considering the other big study that was released this week. New research shows that children bear higher burdens of flame retardants in their bodies than adults. The study, published in Environmental Science and Technology, found that children's PBDE levels are around 2.8 times higher than their mothers.

Linda Birnbaum, director of the National Institute of Environmental Health Sciences, said the new research raises some important questions about public health since it is uncertain just how flame retardants are affecting children or their mothers.

"Newer data showing that PBDE replacements also make their way into household raises the question: do we really need these flame retardants in all of the products where they're being used, like nursing pillows?" she says.

What do you think? Are flame retardants a necessary evil? Or is it time for a phase-out?

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