Phthalates linked to ADHD symptoms

A new report by Korean scientists under Dr Yun-Chul Hong and published in the November 15th issue of Biological Psychiatry increases concerns about the health effects of phthalates, plastic chemicals found  in many consumer products, including toys, cleaning materials, plastics, and personal care items.  Previous studies studies have been inconsistent, with some linking exposure to these chemicals to hormone disruptions, birth defects, asthma, and reproductive problems, while others have found no significant association between exposure and adverse effects.

In this new study the researchers, having measured urine phthalate concentrations and evaluated symptoms of attention-deficit/hyperactivity disorder (ADHD) using teacher-reported symptoms and computerised tests that measured attention and impulsivity,  found a significant positive association between phthalate exposure and ADHD, meaning that the higher the concentration of phthalate metabolites in the urine, the worse the ADHD symptoms and/or test scores.

The U.S. Centers for Disease Control and Prevention, in the Summary of their 2005 Third National Report on Human Exposure to Environmental Chemicals, state that "very limited scientific information is available on potential human health effects of phthalates at levels" found in the U.S. population. Although this study was performed in a Korean population, their levels of exposure are likely comparable to a U.S. population.

The current findings do not prove that phthalate exposure caused ADHD symptoms. However, these initial findings provide a rationale for further research on this association.

For a fuller report

First published in October 2009

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