IV Post

Atlanta, Georgia - An April 10, 2009 article appearing on Salon.com inaccurately represents the Centers for Disease Control and Prevention’s (CDC) 2004 public health response to a request from the Washington D.C. Department of Health for assistance concerning lead in water in District of Columbia neighborhoods (Blood Lead Levels in Residents of Homes with Elevated Lead in Tap Water - District of Columbia, 2004 MMWR Dispatch Vol. 53., March 30, 2004).

Characterization of  CDC’s 2004 MMWR Conclusions: Salon correspondent Rebecca Renner mischaracterizes the 2004 Morbidity and Mortality Weekly Report (MMWR). The MMWR states that “lead in tap water contributed to a small increase in BLLs in D.C.”  Now, as in 2004, CDC continues to stand by its MMWR statement that, “Because no threshold for adverse health effects in young children has been demonstrated, public health interventions should focus on eliminating all lead exposures in children.  Lead concentrations in drinking water should be below the EPA action level of 15 ppb.  Officials in communities that are considering changes in water chemistry or that have implemented such changes recently, should assess whether these changes might result in increased lead in residential tap water.”

Missing Test Results: Ms. Renner’s article contends that missing laboratory test results undermined public health.  As CDC has explained to Ms. Renner many times, in interviews and in written responses, public health surveillance data uses real world health information to support public health decision-making.  It is dependent on health organizations to report data accurately.  In 2004, a participating commercial laboratory stopped reporting test results that fell below the CDC level of concern of 10 µg/dL.  CDC believes this failure of reporting accounts for the missing data because the laboratory continued to report BLLs greater than 10 µg/dL. To the extent “missing” data would have affected overall results, it would have exaggerated the apparent problem, not masked it.  As a part of the 2004 public health consultation, the CDC encouraged the D.C.  Department of Health Medical Director to remind all laboratories and health care providers of their obligation to report all blood lead level tests.

Alleged Scientific Misconduct: Scientific integrity is CDC’s hallmark.  Scientific misconduct has a precise definition, which is “fabrication, falsification, or plagiarism in proposing, performing, or reviewing scientific activities, or in reporting scientific results.”  CDC’s Office of Science takes any such allegation very seriously; it thoroughly investigated this complaint and found no evidence of scientific misconduct.  CDC acknowledges the fact of missing data; however, this fact is unrelated to fabrication, falsification, or plagiarism on CDC’s part.

Communication of Findings: Since 2004, the CDC Lead Poisoning Prevention Program staff and CDC Division of Media Relations have responded to numerous press inquiries about the 2004 D.C. consultation. Moreover since the 2004 investigation information has been shared regularly and rapidly with other public health authorities, local and federal agencies, including the American Public Health Association, DC Water and Sewer Authority, D.C. Lead program officials, the George Washington University School of Public Health’s Water Team, and representatives from the U.S. Environmental Protection Agency.

Allegations by Ms. Renner that, “Scientists from other agencies, including EPA and HUD,…were never told about the results” are untrue or misleading.  For example, CDC’s Lead Poisoning Prevention Branch routinely consults with EPA water experts and solicits their review and comment on a variety of topics.  HUD does not have jurisdiction over issues related to lead and water; CDC works closely with HUD on a variety of other issues related to healthy housing. 

Alleged Failure to Share New Information: In 2007, preliminary findings of the 2004 public health consultation were presented during the annual meeting of the American Public Health Association, and the abstract was published in the annual conference program guide.

It is common practice in scientific circles to present preliminary findings at scientific meetings as a way for researchers to receive comment and advice from other experts.  This presentation did not present complete data analysis nor did it include all the analyses that were planned and necessary for a scientific manuscript.  Since that time CDC has obtained additional statistical analyses, undertaken additional peer review, and continued to strengthen the manuscript. We believe these aspects of the scientific process are essential to conducting and communicating the best quality science.  The manuscript is expected to be published later this year.

Other Scientific Studies: Ms. Renner alleges that “a new scientific study published in January(“Elevated Blood Lead in Young Children Due to Lead-Contaminated Drinking Water: Washington D.C. 2001-2004), Journal of Environmental Science and Technology, Vol.43, No.5, 2009) contradicts CDC’s conclusion of minimal harm.” In fact this study, reaffirms CDC’s conclusions that lead in water contributed to elevations in BLLs and that lead concentrations in drinking water should be below the EPA action level of 15 ppb.

Since 1975, CDC has been a tireless advocate for childhood lead poisoning prevention. Our agency’s commitment to preventing childhood lead exposure is as strong today as it has been since we released the first statement on lead poisoning and its effects on children.