Is there a connection?
Two distinct studies examined the role of PFC (Perfluorinated chemicals) and their possible connection to ADHD and hyperactive/impulsive behavior in children. The studies were published online last month.
Perfluorinated chemicals (PFC) have been used since the 1950s. Commonly used in industry, they can be found in a wide variety of consumer products including, food containers, waterproof fabrics, paints, non-stick cookware, and stain-proof coatings. PFC are actually a class of chemicals that include perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), perfluoroctanic acid (PFOA) and perfluorohexane sulfate (PFHxS).
In the first study, Brooks Gump of SUNY, Oswego, and colleagues assessed impulsive behavior using a computerized test. They compared the test results with PFC in the children’s blood samples. They used a sample of 83 children from Oswego County, N.Y. The children ranged in age from nine to 11 years old.
Gump found that higher concentrations of PFHxS were associated with increased odds of ADHD. Children with the highest exposure to PFHxS were 60 percent more likely to have ADHD and take ADHD medication. Gump could not find a strong correlation with the other PFC and ADHD.
Researchers Cheryl Stein from the Department of Preventive Medicine, Mount Sinai School of Medicine, New York, NY, and David Savitz, Departments of Community Health and Obstetrics and Gynecology, Brown University, Providence, Rhode Island, are authors of a second study published online in Environmental Health Perspectives.
They reviewed data from the C8 Health Project survey conducted between 2005 and 2006. The project examined more than 10,000 parents and their children aged 5- to 18. These families lived in West Virginia and Ohio near a DuPont plant that manufactures PFOA. Commonly, PFC are transferred in food, but the plant seems to have exposed the families to PFOA through groundwater contamination and airborne plant emissions.
Stein and Savitz’s findings from the C8 Study echo results from a previous study done in 2010; higher levels of PFOA were highly associated with ADHD.
Neither of the studies can prove that PFC cause ADHD, only that there is a high degree of association between PFC levels and ADHD. It would be wise to limit exposure to PFC whenever possible. Further studies will have to be performed to determine if health outcomes are affected later in life.
Another environmental contributor to ADHD may be secondhand smoke. A recent study confirms a study done in 2007 by Richard D. Todd, M.D., Ph.D., the Blanche F. Ittleson Professor and director of the Division of Child Psychiatry at Washington University — secondhand smoke may be linked to a greater risk of ADHD and learning disabilities in children.
The current study was funded by the Centers for Disease Control and Prevention (CDC) and the National Center for Health Statistics. The researchers found an amazing correlation between secondhand smoke and ADHD: children exposed to secondhand smoke in the home are twice as likely to develop either ADHD or a learning disability.
Data were collected from parents and guardians of over 50,000 children ages 11 and younger in the US. The researchers found that children exposed to secondhand smoke had a learning disability 8.2 percent of the time, ADHD nearly 6 percent of the time, or another conduct disorder 3.6 percent of the time.
Obviously, the cost of treatment via medical and educational interventions is in the billions of dollars. Environmental factors are something we can control, if we place emphasis on the need to control them. I’m quite certain that as we study the relationship between our environment and our health, greater causal relationships will be revealed.