Data just released from the Centers for Disease Control and Prevention (CDC) show that rates of attention-deficit/hyperactivity disorder (ADHD) continue to rise, jumping from 6.7 percent of U.S. children in 2000 to 9 percent of U.S. children in 2009. As doctors and scientists try to uncover the causes of ADHD, attention is turning to all the chemicals children and pregnant moms encounter in their daily lives. “Certainly there’s a genetic component to the disorder,” says Brooks Gump, PhD, MPH, associate professor in the department of public health, food studies and nutrition at Syracuse University, noting that roughly 50 percent of cases are genetic. “But there are environmental factors involved, as well.” The disorder has already been linked to pesticides found in chemically grown food, and now Gump has shown in a new study that one of the chemical causes of ADHD might be perfluorinated chemicals (PFCs), a class of highly toxic chemicals used to make stain- and water-repellent fabrics and nonstick cookware that linger in the environment for very long periods of time, building up in the blood of animals that enter the food chain and, ultimately, in people.
There have been a few observational studies finding associations between a diagnosis of ADHD and high PFC levels in blood. But Gump’s new study, published recently in the journal Environmental Science & Technology, shows real-world situations in which children with high PFC levels exhibited characteristics of the disorder, mainly impulsive behavior.
WHAT IT MEANS
We’re just beginning to understand the sometimes-subtle effects of these ever-present chemicals. “PFCs are so prevalent,” Gump says. “There’s so little research about what the effects of these are on cognitive function, yet everyone has them in their blood.” And he adds that the levels of PFCs found in the children in his study are not unusual, based on blood tests conducted on the general public by the CDC. Because these chemicals are so ubiquitous, he wasn’t able to determine whether children were being affected by PFCs in their current environment or had been exposed to high levels prenatally. Prenatal exposure, he writes in his study, might explain why these children, born in the late 1990s, when PFC use peaked, are more likely to show signs of ADHD.
A 2008 study has shown that, as with many of the other persistent chemicals that build up in our environment (such as pesticides), contaminated food and water are our primary exposure sources for PFCs. The next-highest source is spray-on water- and stain-repelling clothing treatments and carpet treatments, such as Scotchgard. Third in that list is food packaging: Microwave popcorn, fast-food wrappers, butter wrappers, and pizza boxes may contain PFC-based coatings to prevent grease from soaking through the paper, giving you one more reason not to eat fast food!
Shop the Clemson Area Food Exchange for local, organic food including meats, produce, herbs and cheeses: www.clemsonareafoodexchange.com.