Combined tobacco and lead exposure may pose particular ADHD risk

Tobacco smoke and lead exposure may be linked to a particularly high risk of ADHD, according to findings presented at the 2008 Annual Meeting of the Society for Developmental and Behavioral Pediatrics.

Researchers stated that tobacco and lead exposure together appears to have a synergistic and negative effect. The study estimated that 35% of ADHD in children between the ages of 8 and 15 could be reduced by eliminating both environmental exposures, which equates to more than 800,000 of the 2.4 million children in this age group estimated to have ADHD in the US.

In a separate study, published in the October Journal of Attention Disorders, researchers found significant improvements in concentration among children diagnosed with ADHD or ADD who had taken a 20-minute walk in the park, compared to a walk in a residential area or downtown environment. This benefit was of similar magnitude to that of children with ADHD taking methylphenidate compared with children without ADHD.

The researchers note, however, the lack of objective performance data showing the durability of exposure to a natural environment in managing ADHD symptoms.