Chemicals in Plastic Linked to Low IQs in Kids

A new study links phthalate plasticizers to lowered IQ in third and fourth graders.

March 15, 2010

Chemicals kids are exposed to at home—and in school—may affect their intelligence.

RODALE NEWS, EMMAUS, PA—A new study published in the March issue of Environmental Health Perspectives finds that phthalates (pronounced “THA-lates”), chemicals used to make plastics flexible and artificial fragrances linger, could have an effect on brain function in children who have been exposed to them. These phthalate plasticizers, are being eliminated from children's products in this country due to health concerns. But they're still present in many products children are exposed to on a daily basis, including countless home, medical, and personal-care products, as well as cleaning supplies used in schools.


THE DETAILS: The study authors recruited 667 third- and fourth-grade students from nine schools across South Korea, and gave both the students and their mothers IQ tests. The students also supplied urine samples so researchers could determine the level of phthalates in their bodies. Result: A higher phthalate level was strongly associated with a lower IQ test result. The researchers noted that maternal IQ level had a significant impact on a child's IQ, but after controlling for this variable, they found that phthalates still played a role. Diethylhexyl phthalate (DEHP), a common form of phthalate, was found to be one of the main culprits in terms of its probable effect on brain function. DEHP is most commonly used in synthetic fragrances and soft vinyl products.

WHAT IT MEANS: It isn't fully understood how phthalates affect a child's neural development, according to the study authors, but it may have to do with how the body processes fat, which impacts brain health, or with the way phthalates interact with brain cells. Aside from those concerns, there are other reasons that the Consumer Product Safety Commission recently banned phthalates in products marketed to children. Phthalates are endocrine disruptors, chemicals that interfere with reproductive development, and an ongoing study in New York City is finding that higher phthalate levels seems to lead to early puberty in girls, which in turn predisposes them to obesity. A recent study in mice also found that phthalates may lower immune function.

Read on for ways to get phthalates out of your home and your child's school.

Despite all this, phthalates are still common in many household products, including cleaning products, paints, shower curtains, vinyl upholstery, floor tiles, miniblinds, cosmetics, and so on, and phthalates can migrate out of these products and bind to dust, says Catherine Zandonella, MPH, author of the new book Green Guide Families: The Complete Reference for Eco-Friendly Parents (National Geographic, 2010). "The good thing is that the government has made progress in eliminating them from most products marketed to children," she says. But that still leaves products that aren’t specifically made for for children—and they are numerous and ubiquitous.

Here’s what you can do immediately to protect your child:

•  First, check your home. You have the most control over the products your child is exposed to at home, so start by eliminating any products scented with an artificial fragrance, such as laundry detergents, cleaning products, and personal-care products. As author Rick Smith explained in his recent book Slow Death by Rubber Duck, eliminating scented products can drastically reduce your levels of phthalates. What’s more, phthalates are still found in many shampoos and soaps marketed to children, says Zandonella. She also advises getting rid of vinyl miniblinds and vinyl flooring, if possible, because phthalates migrate out of these products, cling to dust, and wind up on the hands and eventually in the mouths of babies and toddlers crawling on the floor. For that same reason, look for cloth alternatives to vinyl shower curtains. These moves benefit mom and dad as well; phthalates have been linked to certain types of cancer in adults, and one study found that men with higher phthalate levels in their urine had a larger waist circumference (a sign of obesity) than men with lower levels.

•  Next, check school supplies. "If you’re buying your kid school supplies, you should feel confident they won't contain phthalates," says Zandonalla. No surprise there. It's illegal to use them in these products. However, while you’ll be safe with your daughter's Hannah Montana binder, that’s not necessarily the case in large office-supply stores, where products are intended for people of all ages. Therefore, avoid any products made from vinyl (such as three-ring binders with plastic covers), and look for products with labels saying “contains no phthalates.” Failing either of those alternatives, she says, "buy brand-name products from companies that care about their reputations. They have a lot to lose if consumers complain about their products being unsafe." Generally, she says, that just means avoiding generic goods sold at discount stores. "If something doesn’t have a major brand name, as a consumer, there's no one you can go to to complain about it."

•  Then check the school. "Children are at school for at least six hours a day, which is a significant portion of their lives," Zandonella says. Unfortunately, school is a place where they can be exposed to phthalates from cleaning products, scented pesticide formulations, vinyl flooring, even art supplies. The good news is that many states and school districts now require that schools use “green” cleaning products, as well as integrated pest management, a form of pest control that uses pesticides only as a last resort. “Schools are normally cleaned every night,” says Zandonella, “and damp-mopping is recommended for vinyl flooring to remove the dust that contains phthalates." Which is a good thing. But art supplies, including the more sophisticated materials used in high schools, are not yet subject to government regulation, and could contain phthalates.

"Schools have the responsibility to provide a safe environment for kids," says Zandonella. But how to know your child’s school is safe? Pay a visit, and ask questions. When it comes to this issue, teachers and administrators should be happy to show you around. "Check to make sure art rooms and science labs are well ventilated," she says, "and see if the school is using products that aren't designed for kids. You have a right to go into schools and check the conditions for yourself."