The U.S. Centers for Disease Control and Prevention (CDC) recently redefined the “action level” for lead exposure in children. Youngsters are now considered at risk and qualify for careful medical monitoring if they have more than five micrograms per deciliter of lead in their blood—half the previous threshold. Lead poisoning can cause cognitive and behavioral problems, and the American Academy of Pediatrics recommends testing blood lead concentration levels at age 1 and again at 2, when concentrations peak.

Most lead poisoning cases occur in substandard housing units, especially those with window frames still coated with lead-based paint banned since 1978. Families in dwellings built before 1950 should also be vigilant about lead. The Consumer Products Safety Commission cautions that home lead test kits sold online and at hardware stores may not be reliable enough to identify and remove sources of exposure. Professional contractors offer more accurate results.

Children exhibiting blood lead levels above the new threshold are usually monitored, rather than treated with medications that carry serious risks. Once lead sources are removed, children’s blood lead levels typically return to a more normal range within weeks.

The CDC confirms that rather than remedial treatment, the primary goal should be making sure children aren’t exposed to lead in the first place. Fortunately, the levels of most of America’s youngest children today are well below the revised action point, with average blood lead content of 1.8 micrograms, while school-age children, teenagers and adults face little risk.