Brittany Greeson for the Washington Post via Getty Images

In the latest blow to the beleaguered but resolute city of Flint, Mich., the government confirmed this week that one of the most common lab tests for lead may have given falsely low readings.

The Food and Drug Administration said Wednesday that children and pregnant may need to be retested for lead, NBC News reports. The FDA says that some of those mistakenly given a clean bill of health in fact had dangerously high lead levels.

The city of Flint is especially vulnerable because at least 100,000 people were proved to have been exposed to dangerous levels of lead in their drinking water.

Advertisement

Advertisement

According to NBC News, the blood tests were made by Magellan Diagnostics and are the only FDA-approved test used in most doctor’s offices.

“The FDA is deeply concerned by this situation and is warning laboratories and health care professionals that they should not use any Magellan Diagnostics lead tests with blood drawn from a vein,” said the FDA’s Dr. Jeffrey Shuren.

Any adult or child who had blood drawn for a lead test since 2014 may have to be retested, but only if their blood tested was from a vein and not a finger stick.

Advertisement

“The FDA believes that most people will not be affected by this issue, as a majority of Magellan lead tests currently in use in the United States are conducted using blood obtained from a finger or heel stick,” said FDA spokesperson Deborah Kotz.

The Centers for Disease Control and Prevention has reported that children are particularly at risk for lead exposure because of the effect on their developing brains and organ systems, including permanent damage. Lead has also been linked to lower IQ scores, poor school performance, inattention, impulsive behavior, aggression and hyperactivity.

Advertisement

“No safe blood lead level in children has been identified. Lead exposure can affect nearly every system in the body,” according to the CDC.

Read more at NBC News.