Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, March 1, 1992 TAG: 9203010258
SECTION: HORIZON PAGE: E-1 EDITION: METRO
SOURCE: JEFF BAILEY
DATELINE: LENGTH: Long
The new assessment was embraced last May by Vernon N. Houk, a director of one of the Centers for Disease Control in Atlanta and the government's best-known expert on the subject, who declared that if it causes cancer in humans at all, dioxin is only a "weak carcinogen." The Environmental Protection Agency, meanwhile, announced it had seen enough new evidence to conduct an unusual re-evaluation of its dioxin regulations.
This came as good news to the paper industry, which was facing huge costs to curb dioxin emissions.
A case of good science meshing with good business? Had an environmental myth really been overturned? Not quite.
The current reappraisal of dioxin, an industrial byproduct ubiquitous in the environment, is as much a result of a well-financed public-relations campaign by the paper and chlorine industries as it is a result of new research. The two industries' trade associations, the American Paper Institute and the Chlorine Institute, have aggressively promoted two pieces of evidence suggesting dioxin is less dangerous than previously thought.
Yet the first of these vindications turns out to be the paper industry's own claims based on a recount of tumors in a 14-year-old rat study - a recount the industry itself paid for. The second involves a scientific conference the Chlorine Institute sponsored and whose discussions it then interpreted to suit its purposes.
"The industry campaign isn't about science," contends Ellen K. Silbergeld, a University of Maryland toxicologist studying dioxin. "It's the big lie. Say something often enough, people begin to believe it."
Meanwhile, apart from the debate over whether dioxin causes cancer, less attention has been paid to research suggesting dioxin may be more, not less, dangerous than previously known. Several recent studies have strengthened the previously suspected link between dioxin and cancer and also have portrayed dioxin as a powerful hormone-like substance that may affect the reproductive system. Some scientists also fear dioxin may team up with two other toxic substances in the environment-polychlorinated biphenyls (PCBs) and furans - to attack the same cell receptor in the body.
The EPA currently regulates dioxin as if each tiny increase in exposure raises health risks. Paper and chlorine makers say dioxin has no adverse human health effects below a certain threshold, which they say is much higher than the standards the EPA instituted in the mid-1980s. Chlorine, made by some big chemical companies, is used in bleaching pulp for paper.
If the industry view persuades regulators, paper makers could avoid buying more very costly equipment to reduce chlorine use and dioxin emissions. What's more, toxic sites where dioxin was dumped could be reclassified as less dangerous and thus cheaper to clean up. And billions of dollars in legal claims against paper makers and others, alleging that low-level exposure to dioxin caused health and other problems, could evaporate.
Environmental groups and some plaintiffs' lawyers argue the opposite side of the dioxin issue - that it's dangerous even at low levels of exposure - and have resorted to exaggeration as well.
For some, there is an economic incentive to make this argument: The stricter dioxin regulations are, the easier it is to sue chemical concerns and paper makers claiming lower-level exposure was harmful. There are hundreds of such lawsuits pending.
How has the dioxin campaign been so successful?
One big assist has come from Houk, the government expert who received wide exposure last year when he proclaimed dioxin only a "weak carcinogen." Houk also said that current research suggested that the residents of Times Beach, Mo., a town evacuated a decade ago because dioxin-laced oil had been sprayed on its streets, might have been uprooted unnecessarily.
Yet while the government has long looked to Houk for expert advice on dioxin, some scientists researching dioxin disregard his opinions. "I don't know why Vernorn Houk does the things he does," says George W. Lucier, a toxicologist at the National Institute of Environmental Health Sciences, who is working on the EPA reassessment. "I obviously disagree." Houk declined interview requests.
EPA chief William K. Reilly also declined interview requests.
Though considered a dangerous substance for decades, dioxin wasn't an issue for paper makers until 1985, when it was discovered in the waste streams of bleach pulp mills. The American Paper Institute promptly formed a "crisis management team." To the media, the industry tried to portray the matter "as old news," according to institute documents, which advised officials to "suggest that this is a story that was covered way back when."
As the EPA prepared in July 1987 to release findings of a study of dioxin emissions from industry mills, paper institute staffers outlined their strategy in a memo: "Get EPA to . . . characterize as `not a real threat to environment or public health' if possible."By then dioxin was firmly fixed in the national consciousness as a fearsome toxin.
The paper industry scored its first major public-relations success in 1990, when paper companies arranged to challenge the findings of the most influential dioxin study ever done. That study, reported in 1978 by Richard Kociba, a Dow Chemical Co. pathologist, was done on 485 white rats, whose food was spiked with dioxin. Dr. Kociba found a strong link to cancer: A daily dose of billionths of a gram led to tumors.
By 1990, methods for counting tumors had become more sophisticated, and the paper industry seized on this as a chance to review Kociba's study. Paper makers hired five pathologists and brought them to a Maryland lab where, for most of two days in March 1990.
Majority votes on each slide concluded there were 50 percent fewer liver tumors than in the original count, says Robert A. Squire, a pathologist who oversaw the recount. But, he adds, "there wasn't much unanimity. This was an uncertain finding." With the effect only half as great, the panel also asserted dioxin must be a weak carcinogen.
Based on that, the paper institute demanded, in a June 1990 letter to the Food and Drug Administration, to President Bush's science adviser and to Reilly of the EPA, that the government loosen dioxin regulations.
The EPA didn't quibble with the recount itself.
Next, the Chlorine Institute, after discussions with counterparts at the paper institute, arranged to bring three dozen of the world's foremost experts on dioxin to a conference at the Banbury Center on Long Island Sound. Also present was Dr. George L. Carlo, a scientist but not widely regarded as a dioxin expert. "`Carlo is not a scientist with a long history of dioxin credentials," says Lucier, the NIEHS official.
Why was Carlo there? Though described as a "conference participant" by the Chlorine Institute, he was actually the industry's $150-an-hour observer. Based on his account, the institute would later circulate reports that the scientists had reached an important consensus: Dioxin attacks the body through a spot on the cell known as a receptor. That much was correct.
But the Chlorine Institute also said the scientists had agreed that the receptor acts as a sort of biological switch - one that can't be thrown unless dioxin exposure reaches a certain level, or threshold. Beneath that threshold, the institute said, there is no danger.
The institute's statements, however, didn't accurately reflect what had happened at the conference. There had been discussion about the possibility or even the likelihood of such a threshold, but no general agreement that one exists.
In at least one way, the conference turned out to be quite effective. Linda Birnbaum, an EPA toxicologist, returned from the Banbury meeting and wrote a memo to one of Reilly's top assistants outlining the "safe dose," or threshold, discussions.
Meanwhile, Georgia-Pacific's Hahn and three other paper company executives called on Reilly in January 1991 with their version of the Banbury meeting.
They asked again for a reassessment of the EPA's strict dioxin regulations - and suggested "accelerated efforts."
In April 1991, citing the Banbury meeting, Reilly announced the agency's formal reassessment and said he wanted the complex dioxin research done within a year. The EPA reassessment will try to use the receptor mechanism to better predict dioxin's effects and set standards accordingly.
The paper executives who visited Reilly also asked him for something else. The Clean Water Act allows states to set their own dioxin water contamination limits - instead of using the EPA's guideline of no more than 0.013 parts-per-quadrillion - so long as the states' figures are backed by sound science. The paper executives asked Reilly to remind the EPA staff that this flexibility exists.
Less than two months later, Martha G. Prothro, an EPA water official, sent out just such a reminder. "It was certainly a direct result of complaints we had from industry," she says.
The paper industry, using its versions of the rat tumor re-count and the Banbury conference, has urged states to set dioxin water standards far above the EPA figure, often successfully.
Water concentration of dioxin is an important health concern because this is one way it moves up the food chain, through fish to people; most dioxin in human tissue comes from food.
In late 1989, Houk and paper makers backed a water standard substantially higher than the EPA figure, 7.2 parts-per-quadrillion, in Georgia. Houk based his recommendation almost entirely on paper-industry information, according to congressional testimony he gave in July 1990. Georgia took his advice, which the EPA complained "undermined three years of EPA/Georgia coordination to comply with . . . the Clean Water Act." The EPA, which declared Georgia's proposed standard dangerously high, didn't approve it.
The best-regarded research on high-level dioxin exposure, a National Institute for Occupational Safety and Health study of chemical-plant workers, last year reported that cancer deaths among the most highly exposed were 46 percent higher than expected. The NIOSH study, published in The New England Journal of Medicine, contradicted earlier studies backed by chemical makers, notably Monsanto Co., that found no link between occupational dioxin exposure and cancer.
The NIOSH study authors warned that "it is premature to conclude that [dioxin] is not harmful at low levels of exposure."
Reprinted with the permission of the Wall Street Journal 1992, Dow Jones and Co. Inc. All rights reserved.
by CNB