"Federal officials are warning that some blood tests may have 'significantly” underestimated lead levels, and they are urging the retesting of some children, as well as pregnant and breast-feeding women.

The Food and Drug Administration and the Centers for Disease Control and Prevention said the tests in question were made by Magellan Diagnostics, a Massachusetts-based testing company whose products are used in laboratories and doctors' offices throughout the country. The problem may go as far back as 2014, the agency said. The warning applies only to tests in which blood samples are taken from a vein, not the more common, less invasive tests in which fingers or heels are pricked for a blood sample.

In a conference call with reporters, Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health, said the agency's investigation was in its early phases, and that most people probably won't be affected. Still, he said, he was deeply concerned about the inaccurate results and that a “root cause” hasn't been identified."

Laurie McGinley reports for the Washington Post May 17, 2017. [2]