"The nation's premier public health agency knowingly used flawed data to claim that high lead levels in the District's drinking water did not pose a health risk to the public, a congressional investigation has found. And, investigators determined, the agency has not publicized more thorough internal research showing that the problem harmed children across the city and continues to endanger thousands of D.C. residents.
A House investigative subcommittee concludes that the Centers for Disease Control and Prevention made "scientifically indefensible" claims in 2004 that high lead in the water was not causing noticeable harm to the health of city residents. As terrified District parents demanded explanations for the spike in lead in their water, the CDC hurriedly published its calming analysis, knowing that it relied on incomplete, misleading blood-test results that played down the potential health impact, the investigation found."
Carol D. Leonnig Washington Post May 20, 2010.