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CDC misled District residents about lead levels in water, House probe finds

By Carol D. Leonnig
Washington Post Staff Writer
Thursday, May 20, 2010; A01

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.

The city utility says lead levels have been in the safe range in D.C. water since 2006, after a chemical change to reduce lead leaching. But the House report raises concerns about children in 9,100 residences throughout the city with partial lead-pipe replacements. Their parents may not know CDC research has found that children in such homes are four times as likely to have elevated lead in their blood.

The House science and technology subcommittee investigation, scheduled to be released Thursday, was spurred last year by one scientist's research and Washington Post reporting suggesting that the 2004 CDC analysis was missing many test results for children who might have lead poisoning. With its final report, the committee reveals that the missing data showed clear harm to children from the water -- and that CDC authors knew the data was flawed. It finds that CDC officials "failed in their public health duty."

Pediatric lead experts advise concerned parents to monitor their children's behavior to determine whether they have noticed coordination, hearing or mental-focus problems or changes. Parents who witness such changes should have their children's blood tested for lead.

Late Wednesday, the CDC declined to directly rebut the House investigators' findings. Instead, it released a brief re-analysis based on the missing tests, which it said confirms the original 2004 findings that residents did not suffer significant harm.

The agency acknowledged, however, that its 2004 claim that no children had been found with lead poisoning was "misleading," because it referred to only one part of its study. Another part showed that children living in homes serviced by a lead pipes were more than twice as likely as other D.C. children to have unsafe lead in their blood.

Yanna Lambrinidou, head of a parents' activist group that formed in the lead crisis, said the CDC, the city water utility, the U.S. Environmental Protection Agency and the D.C. Health Department knew that lead was spiking in the water but did little to fix it or warn the public.

"CDC gave the perpetrators of D.C.'s lead crisis a 'get out of jail free' card," Lambrinidou said. "They will finally have to answer for what they did."

When nearly 1 million residents throughout the District and in small parts of Falls Church and Arlington learned from a Post article in January 2004 that they had been exposed to unsafe lead in water for at least a year, the CDC analysis was largely used to quiet public anger. The study has since been cited as evidence that even astronomically high lead levels are not cause for concern.

Rep. Brad Miller (D-N.C.), the subcommittee chairman, said the CDC report "left the public health community with the dangerous and wrong impression that lead-contaminated water is safe for children to drink."

Lead is a toxic metal long known to cause brain damage and developmental delays in fetuses and children when they or their pregnant mothers ingest significant amounts.

Marc Edwards, a Virginia Tech scientist who early on questioned the paper, said it's time for the CDC to retract its findings and for the senior author of the 2004 report, Mary Jean Brown, to resign.

The House subcommittee's investigation also chides the CDC for not alerting the public to its subsequent research that contradicted its earlier claims. This 2007 research determined a clear link between the water problem and lead poisoning in D.C. children. For example, it showed that city children with high levels of lead in their blood were significantly more likely to live in homes with lead pipes, and after the city fixed its water treatment problem, the CDC saw a "dramatic reduction" in lead poisoning.

The committee also urged release of this research to alert residents to a continuing, lurking threat in the estimated 9,100 D.C. homes where water utility crews replaced part of the lead service pipe bringing water to the house. The CDC study concluded that the D.C. Water and Sewer Authority's $93 million effort to reduce lead risks after the 2004 lead crisis had largely backfired: Children living in homes with partial lead pipe replacements were four times as likely to suffer from unsafe levels of lead as those in homes without lead pipes.

The House science subcommittee reserves its strongest criticisms for Brown, the CDC's director of lead poisoning prevention. She worked with D.C. health officials to review blood-test results and frame the CDC's response. Brown led a team in publishing the conclusion that the lead problem wasn't having a serious health impact.

But the committee said it found evidence that Brown knew that the D.C. Health Department data was missing thousands of blood-test results in a critical period of the lead crisis. She told investigators that she believed all the missing data was for low blood-lead levels, but she never tried to obtain the original results to check.

The committee did go back to the labs for the original test results for 2002-03 and learned that three times as many children had elevated lead levels as reported, 954 instead of 315. This means child lead poisoning was rising, not falling or staying the same, as the CDC had claimed.

In one part of the 2004 report, the CDC paper analyzed the blood of children and adults living with lead levels in their tap water 20 times the amount raising concern -- and said not one was suffering from elevated lead. Brown and her co-authors knew, however, that most of those tested had been drinking bottled or filtered water before their blood was analyzed.

A public health expert and co-author suggested to Brown in an e-mail that the report mention this factor because "this may help to explain why currently none of the persons have blood lead levels above the level of concern." It was never mentioned.

Brown acknowledged to investigators that she "didn't have a lot of confidence" in the results but didn't delay the report's release because many federal agencies were pushing the CDC to publish.

In internal e-mails at the time, Brown expressed pleasure that the drumbeat of media reports was easing. "Today has been the first day in over a month that there wasn't a story on lead in water in the Washington Post and also the first that I haven't been interviewed by at least one news outlet," Brown wrote to her boss. "I guess that means it worked!"

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