A study recently published online in Pediatrics found that both lead and tobacco are linked to Attention Deficit Hyperactivity Disorder (ADHD). According to the researchers, lead and tobacco are not only linked to ADHD but together they are synergistic, yielding a greatly increased risk factor as opposed to one or the other alone. According to Tanya Froehlich, MD, of the Cincinnati Children’sHospital Medical Center, and colleagues, the adjusted odds ratio was 8.1 for both risk factors combined with a 95% confidence interval from 3.5 to 18.7. The researchers said that if exposure to tobacco and lead are actually causing ADHD avoiding both of these could prevent as much as 22.5% to 47% of ADHD cases in the United States. Click here to read an article from WebMD that discusses this study more.