NOTE: The following is one of a series of case studies produced by the Union of Concerned Scientists' Scientific Integrity Program between 2004 and 2010 to document the abuses highlighted in our 2004 report, Scientific Integrity in Policy Making.
Lead poisoning has long been recognized as a serious threat to children. The Centers for Disease Control (CDC) estimates that more than 400,000 children in the United States under the age of five have elevated levels of lead in their blood, which can cause many serious ailments including brain damage and central nervous system disorders.1
As authorized by Congress, the CDC has impaneled a group of experts since the 1970s to advise the government on how to best protect children from lead poisoning—one of some two dozen advisory committees within this agency alone.2 Over the last several decades the committee has gradually lowered the threshold for acceptable exposure to lead--which stands at 5 micrograms of lead per deciliter of blood in 2012--and the incidence of elevated lead levels in children has been reduced substantially over that period.3 However, at times the scientific work of this committee has been subject to political interference.
Industry interference in a CDC advisory committee
In the summer of 2002, the CDC Advisory Committee on Childhood Lead Poisoning Prevention was preparing to consider whether to revise the federal standard for lead poisoning set most recently in 1991. Initially, in 1975, the CDC had officially defined lead poisoning as the presence of more than 30 micrograms of lead per deciliter of blood. Over time, as emerging scientific evidence showed a health threat from even lower levels of lead exposure, the CDC altered its standard. The lead poisoning threshold was lowered in 1985 to 25 micrograms per deciliter and, in 1991, was further reduced to 10 micrograms.4
According to numerous sources familiar with the committee's work, the advisory group at this time was likely to rule in favor of a more stringent federal standard for lead poisoning, reflecting the latest research linking ever-smaller amounts of lead exposure to developmental problems in children.5
Just a few weeks before the committee's scheduled meeting, at which the question of toughening the standard further would be discussed, the George W. Bush administration intervened. Tommy Thompson, secretary of Health and Human Services (HHS), took the unusual step of rejecting nominees selected by the staff scientists of a federal agency under his own jurisdiction6. According to Dr. Susan Cummins, who chaired the CDC's lead advisory committee from 1995 to 2000, this was the first time an HHS secretary had ever rejected nominations by the committee or CDC staff.7 In place of the respected researchers the CDC staff had recommended,8 Thompson's office appointed five individuals who were all distinguished by the likelihood that they would oppose tightening the federal lead poisoning standard.9
Furthermore, a review by congressional staff members soon uncovered the fact that at least two of the new appointees had financial ties to the lead industry.10 One of them, Dr. William Banner, an Oklahoma-based toxicologist and medical director of the Oklahoma Poison Control Center, had previously testified in court on behalf of the Sherwin-Williams paint company in a lead poisoning case. In his capacity as an expert witness for this manufacturer, Banner declared that, in his view, studies had never adequately demonstrated a link between lead exposure and cognitive problems in children at any level below 70 micrograms per deciliter.11 In this respect, Banner holds what several leading medical specialists on lead consider a "fringe" view in his field (far from even the normal extremities of mainstream expert scientific discourse). As one medical researcher explains it, Banner's position either ignores or willfully misreads some four decades' worth of accumulating data on lead exposure in children.12
Researchers may well reasonably debate whether the government should tighten its standard for lead poisoning. The public needs and deserves such an informed debate. In this case, however, the Bush administration effectively denied the public an informed policy recommendation by tampering with the integrity of the advisory panel nominating process.
To make room for his appointees, Secretary Thompson's office dismissed Dr. Michael Weitzman, a highly respected lead expert who had served for four years on the panel. Weitzman is chief of pediatrics at the University of Rochester School of Medicine and executive director of the American Academy of Pediatrics Center for Child Health Research. Unlike Banner, Weitzman has conducted research on lead exposure and published widely on the subject in peer-reviewed journals. Weitzman states that shortly before he learned of his rejection by Secretary Thompson, CDC staff told him they planned to nominate him to chair the advisory committee.13
The dismissal of Weitzman and the rejection of other CDC-recommended candidates came via direct intervention from HHS Secretary Thompson's office. Department spokesperson William Pierce explained that some 258 advisory panels fall under the purview of HHS and, under the Bush administration, the department "closely and actively over[saw]" the appointment of some 450 scientists to these panels annually. HHS, Pierce continued, did not consider itself bound by any particular agency nominations for committee positions; rather, Secretary Thompson's staff "[took] into consideration recommendations from people inside and outside of the federal government."14
"We've seen a consistent pattern of putting people in who will ensure that the administration hears what it wants to hear," said Dr. David Michaels, a research professor in the Department of Environmental and Occupational Health at George Washington University's School of Public Health and former assistant secretary for environment, safety and health at the DOE during the Clinton administration. "That doesn't help science, and it doesn't help the country."15
As Michaels pointed out, political appointees may be hired to further a given political agenda, but scientific advisory committees have a distinctly different role: namely to "advise agencies and the public about what is the best science." When the process becomes politicized, he noted, "the committee's role will be hampered, the nation's best scientists will shun involvement, the government's credibility will suffer, and the public will lose vital input to the government on behalf of its safety and health."16
A new approach to lead regulation
In January 2012 the Advisory Committee on Childhood Lead Poisoning Prevention released a report recommending a comprehensive overhaul? in how the CDC treats blood lead levels (BLL) in children.17 The report’s core scientific claim is that there is no safe level of exposure to lead for children, since strong evidence shows that even BLL’s less than 10 micrograms may cause irreversible developmental problems in children, including brain, lung, and heart damage. It recommends that the CDC eliminate the 10 microgram “level of concern” standard altogether and switch to a prevention-based approach. The goal of this approach is to pre-emptively avoid lead exposure rather than handle cases of exposure exceeding a certain limit after they occur. To implement this strategy, the CDC is asked to set a BLL reference value at the 97.5th percentile of BLL’s in children and use that value to identify regions and populations at greatest risk for lead exposure. The CDC is advised to reduce those risks and update the reference value every four years. In May 2012 the CDC adopted the Committee’s recommendations and set the first reference value at 5 micrograms.18
Note: This page is an excerpt from the 2004 UCS report Scientific Integrity in Policymaking.
1. See http://www.cdc.gov/nceh/lead/.
2. Information provided by CDC Press Offi ce, December 2003.
3. For evidence of the decline in lead levels in children since the 1970s, see http://www.cdc.gov/nceh/lead/data/national.htm.
4. For example, see Centers for Disease Control, Preventing Lead Poisoning in Young Children: A Statement by the Centers for Disease Control, Report No. 99- 2230, Atlanta, GA: CDC, U.S. Department of Health and Human Services, 1991.
5. Author interviews with Michael Weitzman and others, November 2003.
6. Author Interview with Susan Cummins, December 2003.
8. The nominees recommended by the CDC but overruled by Secretary Thompson's office include: Dr. Bruce Lanphear, Sloan Professor of Children's Environmental Health at the University of Cincinnati and a former member of the Lead Poisoning Prevention Task Force in the Monroe County Health Department; and Dr. Susan Klitzman, associate professor of urban public health at the Hunter College School of Health Sciences and the former head of the New York City Health Department's lead poisoning prevention program. Both have published multiple papers on lead poisoning in peer-reviewed medical literature.
9. The Bush administration nominees to the panel were William Banner, Kimberly Thompson, Sergio Piomelli, Tracey Lynn, and Joyce Tsuji. Dr. Tsuji ultimately withdrew her nomination. For more on their qualifications and links to the lead industry, see the Office of Representative Edward J. Markey, "Turning Lead Into Gold: How the Bush Administration is Poisoning the Lead Advisory Committee at the CDC," October 8, 2002. Online at www.house.gov/markey/iss_environment_rpt021008.pdf.
10. Ibid. At the time of his nomination, Dr. Banner, an attending physician at Children's Hospital at the University of Oklahoma College of Medicine, was retained by the Lead Industries Association as an expert witness in an ongoing legal case between the State of Rhode Island and the lead paint industry. Dr. Kimberly Thompson, an assistant professor of risk analysis and decision science at the Harvard School of Public Health, has no fewer than 22 funders with a financial interest in the deliberations of the CDC panel and at least two—Atlantic Richfield Corp. and E.I. Dupont de Nemours and Co.—named as defendants in the Rhode Island case against the lead paint industry. Despite their industry connections, a standard government vetting of Drs. Banner and Thompson found no financial conflict of interest that would legally prohibit them from participating in the new advisory committee. See minutes of the committee meeting, October 15-16, 2002.
11. Deposition of Dr. William Banner, Jr., June 13, 2002, in State of Rhode Island v. Lead Industries Association, C.A. No. 99-5526 (Superior Court of RI, April 2, 2001)as cited in Politics and Science report, p. 23.
12. Author interview with prominent lead poisoning expert, name withheld on request.
13. Author interview (via email) with Michael Weitzman, November 2003.
14. Author interview with William Pierce, U.S. Department of Health and Human Services Press Office, November 2003.
15. Author interview with David Michaels, October 2003.
16. Ibid. See also David Michaels et al., "Advice Without Dissent," Science, October 25, 2002.
17. Advisory Committee on Childhood Lead Poisoning. 2012. Low Level Lead Exposure Harms Children: A Renewed Call for Primary Prevention. Centers for Disease Control, January 4. Online at http://www.cdc.gov/nceh/lead/ACCLPP/Final_Document_030712.pdf
18. Hartocollis, A. 2012. CDC Lowers Recommended Lead-Level Limits in Children. New York Times, May 16. Online at http://www.nytimes.com/2012/05/17/nyregion/cdc-lowers-recommended-lead-level-limits-in-children.html