Sunday, March 22, 2009

A New Congressional Inquiry into Scientific Integrity Highlights Lead in DC Drinking Water

On Thursday, March 12, 2009, the US House Subcommittee on Investigations and Oversight held a hearing on the federal Agency for Toxic Substances and Disease Registry (ATSDR) -- an agency under the aegis of the Centers for Disease Control and Prevention (CDC). The staff report for this hearing -- which argues that ATSDR is doing an abysmal job of fulfilling its mission to prevent human harm from toxic substances through reliable science, proper public health actions, and accurate information -- discusses, among other cases, lead in DC's drinking water. In its introduction, the report paints a grim picture of ATSDR:
"[A]cross the nation local community groups believe that ATSDR has failed to protect them from toxic exposures and independent scientists are often aghast at the lack of scientific rigor in its health consultations and assessments. The studies lack the ability to properly attribute illness to toxic exposures and the methodologies used by the agency to identify suspected environmental exposures to hazardous chemicals are doomed from the start. [...] [T]ime and time again ATSDR appears to avoid clearly and directly confronting the most obvious toxic culprits that harm the health of local communities throughout the nation. Instead, they deny, delay, minimize, trivialize or ignore legitimate concerns and health considerations of local communities and well respected scientists and medical professionals" (pp. 1-2; emphasis added).
One might wonder what ATSDR has to do with the District's lead-in-water problems.

Think CDC 2004. Actually, think CDC 2004-2009.

On March 30, 2004, exactly two months after the Washington Post informed District residents that for two and a half years the drinking water in thousands of DC homes had been contaminated with lead, the CDC's National Center for Environmental Health (NCEH) published a report with the DC Department of Health (DOH) that flew in the face of prior scientific knowledge about the health effects of lead in drinking water on the most vulnerable populations: infants and young children (see, Edwards et al. 2009 and our 2/25/09 blog entry). CDC/DOH's conclusion was the following:
"The findings in this report, indicate that although lead in tap water contributed to a small increase in BLLs [blood lead levels] in DC, no children were identified with BLLs [equal to or greater than] 10 ug/dL, even in homes with the highest water lead levels."
10 ug/dL is the CDC's "level of concern" for children aged 6 months-15 years. The report's take-away message was that two and a half years of exposure to lead-contaminated drinking water resulted in no measurable harm.

The CDC/DOH report was quoted ad nauseam by local and federal government officials (see select quotes). WASA, which used it in its 2008 campaign to convince the public that it was time to terminate its accelerated lead service line replacement program, cites the CDC/DOH findings on its website even today (e.g., 2006 news release, 2008 press release & fact sheet). The relief that the CDC/DOH publication brought to all those responsible for the safety of DC's drinking water was most powerfully expressed at a 9/22/04 oversight hearing on WASA by then City Council Member Carol Schwartz, Chair of the Committee on Public Works and the Environment. Responding to the assertion by Lynette Stokes, PhD, MPH, a DOH employee and one of the report's co-authors, that even those residents in homes with the worst lead-in-water levels were left essentially unscathed by the contamination, Ms. Schwartz rejoiced: "That is a marvelously, enormously, encouraging thing" (see video excerpt below).

Dr. Stokes was a former employee of the ATSDR (see our 2/25/09 and 1/31/09 blog entries). NCEH, the Center at the CDC that co-authored the CDC/DOH report is a sister agency to ATSDR. NCEH and ATSDR are managed by the same director, Howard Frumkin, MD, MPH, DrPH. According to the US House Subcommittee on Investigations and Oversight, Dr. Frumkin (and his predecessors) has displayed a persistent lack of concern about the scientific integrity of the reports produced by ATSDR. The Subcommittee's staff report for the March 12, 2009 hearing says:
"[T]he local communities that the ATSDR was created to help protect often believe the agency does more harm than good by offering them reassuring but unfounded and unsound advice and analysis which simply creates an artificial perception of safety to the public that is not supported by scientific inquiry or independent examination" (p. 4).
Today we know that the 2004 CDC/DOH report contradicted not only previous scientific research, but also evidence based on data collected in Washington DC. In April 2004, the Environmental Protection Agency's (EPA) National Center for Environmental Assessment used biokinetic modeling, which when extrapolated to the DC population predicted at least 600-700 cases of elevated blood lead levels (equal to or greater than 10 ug/dL) for children under 6 in 2003 (Edwards et al. 2009, Supporting Information). In 2004 and 2006, media reports featured cases of individual children who experienced elevated blood lead levels from DC's lead-contaminated water. In 2006, Virginia Tech water corrosion expert and MacArthur Fellow Marc Edwards, PhD discovered that -- contrary to public claims by DOH -- several WASA-funded environmental assessments at the homes of children with elevated blood lead levels pointed to drinking water as the sole or a contributing source of lead in 2004. In January 2009, Virginia Tech and the Children's National Medical Center showed that, consistent with the EPA models, in 2001-2004 hundreds if not thousands of DC infants and toddlers experienced elevated blood lead levels (equal to or greater than 10 ug/dL) as a result of high lead at the tap (Edwards et al. 2009).

The true facts about the harm done to DC residents from the 2001-2004 lead-in-water crisis were neither "marvelously" nor "enormously" encouraging. They were not encouraging at all.

The CDC's NCEH and DOH arrived at their misleading conclusions through some of the same flawed research methods characterizing many of ATSDR's reports:
  • Posing the wrong questions: The CDC/DOH study asked whether DC residents as a whole were harmed from chronic exposure to lead-contaminated water, rather than whether infants and toddlers were harmed from this exposure. By asking the broader question, CDC and DOH failed to look carefully at the age groups known to be most vulnerable to adverse health effects from lead at the tap. Infants are especially prone to harm from high lead in water due to their small body weight and heavy reliance on water as a major component of their diet via consumption of reconstituted formula.
  • Relying on inadequate or flawed data: The CDC/DOH study relied on blood lead data from DOH. According to Dr. Edwards, DOH's 2003 dataset was riddled with errors and inaccuracies, and thousands of blood lead records are unaccounted for.
  • Overlooking exposed people: The CDC/DOH study did not take into account individual cases of DC children whose elevated blood lead levels were linked to lead-contaminated drinking water. The story of at least one such case was featured in the Washington Post almost 4 weeks before the report's publication.
  • Diluting exposed populations with unexposed populations: The CDC/DOH study lumped all blood lead measurements from DC together (i.e., infants, toddlers, children under 6, children over 6, and adults) and conducted a citywide analysis, an approach that can mask population groups or geographical areas disproportionately affected from a given exposure.
  • Using inappropriate comparisons: In the CDC/DOH study there was a delay of months to a year between the time residents in homes with the worst lead-in-water problems were informed that their water was contaminated (and took measures to protect themselves from exposure) and the time their blood was tested for lead. Because the half-life of lead in blood is 28-36 days, blood lead levels tend to drop relatively quickly when the exposure source is eliminated. Moreover, all 17 children included in this analysis were using bottled or filtered water at the time of their blood test. As a result, this study had no chance of detecting the harm done to DC residents from excessively high lead-in-water levels, contrary to the public presentation of the data as "worst case."
In 2007, Dr. Edwards submitted to the CDC two 20-page letters detailing possible scientific misconduct in connection with the 2004 CDC/DOH report. The CDC dismissed his allegation without rebutting any of his specific facts. Then, in January 2009, when the Virginia Tech/Children's National Medical Center study contradicting the CDC/DOH report made front page news in the Washington Post, Dr. Frumkin publicly defended his agency's misleading report and minimized the seriousness of the new revelations (see the US House Subcommittee staff report, science reporter Rebecca Renner's 1/29/09 blog entry, and our 2/5/09 blog entry). In February 2009, Parents for Nontoxic Alternatives and our colleagues at the Alliance for Healthy Homes and Lead Safe DC wrote to Dr. Frumkin to suggest that he correct the record with a letter to the Washington Post stating clearly and accurately what the new findings actually mean. Here's what we suggested as one example of a more appropriate message:
The recent study demonstrates that the 2001-2004 lead-in-water crisis had many more adverse impacts and affected far more children than previously believed. There is no medical intervention that can help children already exposed, but we can and must continue working to understand the causes and extent of this problem and prevent further exposures. We know that exposure to lead at the levels reported are likely to cause a population decrease in IQ and educational performance. The presence of this toxin in our water supply has a negative impact on children in DC.

Since questions remain about the quality of DC water, we encourage residents, particularly those with children or who are pregnant, to carefully follow the advice issued by DC WASA, the DC Department of Health, and the Centers for Disease Control and Prevention. This includes never using hot tap water for cooking or drinking and running the tap for 2 minutes before use for cooking and drinking, if water has been stagnant for several hours. Commercially available water filters recognized by the National Sanitation Foundation for filtering lead are also effective. These precautions are even more important when tap water is used for mixing infant formula, powdered milk, or juices.
In his response, Dr. Frumkin did not address our suggestion. Instead, he remarked that WASA's "persistent misstatement" that CDC/DOH identified no harm from the 2001-2004 lead-in-water crisis was "regrettable." And he closed with one last defending statement about his agency's misleading report: that it concluded with the clear message that "public health interventions should focus on eliminating all lead exposure in children."

What a marvelous truism...

Video excerpt: 9/22/04, former DC Council Member Carol Schwartz, then Chair of the Committee on Public Works and the Environment that oversaw WASA, responds with jubilation to the news that none of the residents living in homes with the highest lead-in-water levels were harmed from the 2001-2004 contamination. Today we know that this CDC/DOH "study" had no chance of detecting harm from the years of high lead. Its first author, Mary Jean Brown, ScD, RN, Chief of the CDC's Lead Poisoning Prevention Branch has now admitted that the work was "clearly" not scientific.

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