Faulty lead tests worry U.S. regulators

Certain tests used to measure blood lead levels in children and pregnant women are inaccurate and may underestimate true concentrations, the Food & Drug Administration and the Centers for Disease Control & Prevention warned on May 17. Complaints about the tests, which are produced by Magellan Diagnostics, date back to 2014, the agencies said. The government’s warning “is based on currently available data that indicate Magellan lead tests, when performed on blood drawn from a vein, may provide results that are lower than the actual level of lead in the blood,” FDA said. The agency believes the tests are accurate, however, when used with blood from a finger or heel stick. FDA also believes other blood lead testing methods, such as atomic absorption spectroscopy, are accurate. It is unclear why Magellan lead tests perform differently with venous blood than with capillary blood from a finger or heel stick, FDA said.