A study of more than 5,000 children born in Rochester showed that children who had two or more surgeries before they were 2 years old were twice as likely to be diagnosed with the attention disorder later in life. Doctors believe general anesthesia could be the cause.

Scientists focused on a chemical found in drinking water in Ohio and West Virginia, but they also say it exists in smaller amounts in Washington County. But a health official in Minnesota cautions that studies so far on perfluorooctanoic acid, of PFOA, have been inconsistent and the latest research doesn't necessarily mean there is an increased risk of cancer here.

Maltreatment or even witnessing family violence can cause cognitive harm on par with lead exposure, according to research from the University of Minnesota and Boston Children's Hospital. The study suggests children younger than 2 are the most vulnerable.