A recent Duke University study of Connecticut school children found even small levels of lead exposure — less than the levels the Environmental Protection Agency considers safe — significantly reduced their test scores.

Researchers discovered that the greater the exposure to lead, the lower the Connecticut Mastery Scores. What is most alarming is that children with lead levels lower than the EPA’s established 10 microgram minimum were doing worse on tests than children who had never been exposed to lead. In addition, African-American children were more likely to experience lead poisoning from paint residue, dust or other sources by age 7 than other children. The Childen’s Environmental Health Initiative at Duke found similar results in a study it conducted two years ago of school children in North Carolina.

Duke researchers reviewed the cases of 35,000 Connecticut children whose blood tests showed lead exposure before age 7, then linked them to their fourth-grade reading and math scores on the 2008 and 2009 standardized Connecticut Mastery Tests.

Francesca Provenzano, health program supervisor for the Connecticut Department of Health told the Associated Press: “It’s compelling evidence. I think it provides even greater awareness to parents, medical providers and advocates that lead poisoning is a serious issue and prevention is key.”

Although lead poisoning cases have dropped significantly in recent years, the Duke study is a reminder that this toxic metal is still poisoning children. The only way to find out if your child has been poisoned by lead is through a blood test. The most accurate way to find out if your home or business contains lead is to have state licensed lead inspectors test the structure.

Lead was banned in paint in 1978. Unfortunately, structures built pre-1978 probably contain lead paint. Disturbing lead paint – even simply opening or closing a window – can send lead dust flying through the air. Lead dust is the leading cause of lead poisoning in the three most at-risk groups: children, pregnant women and pets. But everyone is at risk and needs to take precautions, especially during renovations.

The Centers for Disease Control says that a speck of lead dust, as small as a grain of sand, is enough to poison a child.