"The increase is the result of the government last year lowering the threshold for lead poisoning."

"An estimated 535,000 young children in the United States have harmful levels of lead in their bodies, putting them at risk of lost intelligence, attention disorders and other life-long health problems, according to a new estimate released Thursday by federal health officials.

The new number shows lead poisoning affects 1 in 38 children ages 1 to 5, according to the report by the Centers for Disease Control and Prevention.

'To the extent that Americans think this is a problem of the past, clearly this is evidence there is still a problem,' said Rebecca Morley, executive director of the National Center for Healthy Housing, a non-profit lead-poisoning-prevention advocacy group."

Alison Young reports for USA TODAY April 4, 2013. [2]