Cigarettes and lead linked to attention disorder

Nearly half a million cases of attention-deficit hyperactivity disorder among U.S. children are related to exposures to lead or their mothers’ smoking while pregnant, a nationwide study suggests. The two environmental hazards might account for more than a quarter of drug-treated ADHD cases.

The finding bolsters earlier research that linked smoke exposure to ADHD and provides the best evidence yet that lead, a brain-damaging metal, might also contribute to the common behavioral disorder.