National Research Council Poisons Arsenic Debate

One often-heard claim in the controversy over arsenic in drinking water is that the prestigious National Academy of Sciences said the current arsenic standards should be tightened.

The NAS, though, never made any such recommendation.

The recommendation instead came from a subcommittee of something called the National Research Council — an NAS affiliate that exploits the NAS' reputation to give its recommendations more credibility than they deserve. Congress established the NAS in 1863 to provide scientific advice to the federal government. It evolved into a membership organization for the crème de la crème of U.S. scientists. New members are elected by current members based on recognition of distinguished achievement in original research.

The NAS created and delegated to the NRC in 1916 the responsibility of advising the federal government on scientific issues. Because the NAS doesn't receive federal appropriations directly in the budget process, the NRC performs these advisory duties on a for-hire basis.

In the case of arsenic, the U.S. Environmental Protection Agency contracted with the NRC to review and report on the science relevant to the drinking-water issue.

For years the EPA has wanted to reduce the arsenic standard but was stymied by controversy over the relevant science. The EPA's own expert panel on arsenic concluded in 1997 that arsenic did not directly cause cancer. Available human data on U.S. populations doesn't indicate typical arsenic levels in drinking water cause cancer or other health effects — no doubt this is why the current arsenic standard is almost 60 years old.

As per standard operating procedure, the NRC formed a special subcommittee to satisfy its EPA customer. The Subcommittee on Arsenic in Drinking Water amply illustrates the problem with confusing the NRC and the NAS.

The NRC's subcommittees are not made up of the distinguished scientists that comprise the NAS membership. Not one NAS member was on the arsenic subcommittee.

Subcommittee members aren't necessarily even the top experts on the particular issue. Arsenic subcommittee chairman Robert Goyer and five other of the 16 subcommittee members never published a study on arsenic and cancer. NRC subcommittee members tend to be second- or third-tier scientists who seem more interested in the apparent prestige of serving on an NRC subcommittee and advancing their own career interests rather than the cause of science.

Though the NRC supposedly picks subcommittee members independently of the customer agency, many familiar with the NRC process say that agencies, particularly the EPA, exercise behind-the-scenes influence and even veto power over member selection.

The scientists' eagerness to serve and please renders them pliable to NRC management and the customer agency in a way that no NAS member would probably accept.

This pliability is evidenced by the NRC practice of driving subcommittee members to reach consensus on an issue. While consensus-building is a sensible political move, it is antithetical to science. In politics, differing sides may reasonably compromise. Science, though, is about the search for truth. Viewpoints are ultimately right or wrong.

Instead of issuing reports describing the different scientific views of subcommittee members, the NRC forces reports to present compromise conclusions that satisfy few, other than the NRC and client agency, and short-circuit science.

An example of this phenomenon goes to the heart of the arsenic in drinking water controversy. There is no dispute that studies of human populations with high levels of arsenic in drinking water have higher rates of cancer. But what is their relevance to the U.S. where drinking water supplies typically have much lower levels of arsenic?

Some scientists advocate use of mathematical models to predict cancer risk from these lower levels of arsenic exposure. The assumptions used in these models are critical.

The EPA's model assumes that any exposure to arsenic increases cancer risk and that cancer risk increases in a linear fashion with increasing exposure. Other models assume there is a "safe" level of exposure or are "sublinear" with increases in cancer risk that are negligible at low doses. Virtually all known toxicological processes follow a sublinear model.

Based on a variety of biochemical, toxicological and human study findings, the subcommittee stated in its report that only the sublinear models were plausible. But because subcommittee could not agree on which sublinear model was correct, the consensus forced by the NRC/EPA process — incredibly — was to opt for the EPA's linear model, the very model the arsenic subcommittee decided was wrong.

The linear model forced by the NRC process ensured a conclusion that the arsenic standard for drinking water should be lowered. The EPA got the conclusion it paid for.

President Bush this week said he planned to make environmental decisions based on sound science. But last week, EPA Administrator Christine Todd Whitman "asked the National Academy of Sciences" to review again the arsenic issue and recommend a precise standard.

Someone should enlighten Ms. Whitman on what asking the "National Academy of Sciences" really means and that NRC pronouncements do not necessarily reflect the best scientific knowledge.