Many children and pregnant women may need to get new lead tests because one of the most common lab tests may have given falsely low readings, the Food and Drug Administration said Wednesday. They may have mistakenly been given a clean bill of health when in fact they had dangerously high lead levels, the FDA said. The blood tests were made by Magellan Diagnostics and it’s the only FDA-approved test used in most doctor’s offices, the FDA said. Any adult or child who had blood drawn for a lead test since 2014 may have to be re-tested, the FDA said. Finger-prick tests are exempt for now. It’s a big issue because of the Flint, Michigan, water crisis, in which at least 100,000 people were exposed to dangerous levels of lead in their drinking water. Studies have shown many U.S. public water supplies are contaminated by lead.