New Study Highlights Need for Overhaul of NIH Carcinogen Listing Process

Washington, D.C., January 18, 2012 — Just a week after the National Institutes for Health revised its process for listing carcinogens, the Competitive Enterprise Institute released a new study underscoring why the program still needs a major overhaul.

In a January 11 Federal Register notice, the Institute’s National Toxicology Program (NTP) published revisions to the procedures it uses for listing substances in the biennial Report on Carcinogens (RoC). But according to Dr. Richard Belzer, the author of CEI’s study, these revisions do not appear to address any of the RoC’s major deficiencies.

Belzer’s report examines the program’s listing criteria, which he explains result in listings that “are not scientific determinations so much as policy decisions justified, where possible, by science.” Statutory ambiguity “enables the NTP to reserve to itself the discretion to consider whatever information it wants, to exclude whatever information it wants, and to evaluate that information in accordance with whatever ad hoc criteria it wants to apply.”

“Worse,” Belzer continues, “the NTP appears to be institutionally incapable of incorporating decades of advancements in scientific knowledge into its listing decisions, and there is no transparent way to scientifically rebut or reverse a listing decision once it has been made.” Among the key reforms that Belzer recommends Congress make is to require NTP to rely on a “strictly scientific weight-of-evidence scheme” for assessing chemicals that is both transparent and reproducible. Congress also should replace the RoC’s current, nonscientific carcinogen descriptors with terms that “explicitly state alternative levels of concern in units scientists understand, such as probabilities.” NTP determinations also would be more objective and more useful to the public if the NTP paid attention to important differences in potency across substances and the levels to which people are actually exposed. Currently, neither of these essential scientific factors plays any role in NTP determinations.

Belzer also recommends that Congress require the NTP to affirmatively comply with information quality guidelines that were published in 2002. “An enforceable statutory mandate,” says Belzer, “would dramatically improve the scientific quality” of the RoC.

Unfortunately, the NTP’s recent effort to reform its process failed to address these issues. “To make the Report on Carcinogens a genuine science compendium, Congress needs to legislate significant reforms,” says Belzer.

>> Read Dr. Richard Belzer’s full study, “The Report on Carcinogens: What Went Wrong and What Can Be Done to Fix It,” here.