Formaldehyde Labeled a Carcinogen
A World Health Organization panel has upgraded its assessment of the danger of formaldehyde, declaring for the first time that the chemical is “carcinogenic to humans.”
The warning from the International Agency for Research on Cancer contrasts with the approach taken by the Bush administration in February, when the Environmental Protection Agency approved an industry-backed rule intended to spare many plywood and timber-product plants from strict formaldehyde emission controls.
In doing so, the EPA adopted a far more lenient assessment of formaldehyde danger. Administration officials said the controversial change was justified by the “best available science.”
Administration critics Tuesday characterized the international health group’s action as a rebuke of the EPA’s handling of the matter. An industry representative downplayed the international finding, noting that the reclassification of formaldehyde was not a finding of actual risk.
The World Health Organization panel, made up of 26 scientists from 10 countries, reviewed the latest literature and concluded that formaldehyde posed a greater hazard than previously thought.
“Based on this new information, the expert working group has determined that there is now sufficient evidence that formaldehyde causes nasopharyngeal cancer in humans, a rare cancer in developed countries,” said a statement Tuesday from the agency’s headquarters in Lyon, France. Nasopharyngeal refers to the area in the back of the mouth and nose.
The organization’s previous evaluation of formaldehyde had concluded it was “probably carcinogenic.” Review of the latest epidemiological studies “increased the overall weight of the evidence” about the toxic chemical, the expert panel said.
The scientists included in their assessment recent studies by the National Cancer Institute and the National Institute of Occupational Safety and Health showing that exposure to formaldehyde might also cause leukemia in humans. The panel concluded that evidence of such a link was “strong but not sufficient” to establish a causal relationship.
The administration adopted its less stringent formaldehyde risk assessment shortly after the leukemia studies were disclosed. The EPA wood products rule did not mention leukemia risk. White House and EPA officials said this was because the two U.S. studies and a third in England appeared contradictory and were not thoroughly reviewed.
The WHO scientists took a different view. The link to leukemia “reflects the epidemiologists’ finding of strong evidence in human studies,” an organization statement said.
It also noted that the international experts had not yet determined how formaldehyde would cause leukemia. The panelists called for more study of leukemia risks.
Administration officials said it was too soon to say what effect the international group’s decision could have on the EPA.
“The science on formaldehyde continues to evolve,” EPA spokeswoman Cynthia Bergman said. “We are eager to take a close look at their findings.”
The EPA is doing its own evaluation of formaldehyde and has said it will adjust its risk assessment if it finds merit in the leukemia or other studies.
Betsy Natz, executive director of the Formaldehyde Council Inc., an industry trade association, said the international health agency had “simply tried to answer the question of whether, under any circumstances, formaldehyde could produce cancer in humans.”
She noted that some of the cancers cited as a basis for reclassification were based on exposure of workers in decades past, before modern industrial hygiene and safety standards were in place.
Others said the new findings showed that the Bush administration failed to protect the public and called for reconsideration of the timber products rule.
“The Bush administration is out of step with the international community on yet another important issue for public health and the environment,” said Rep. Henry A. Waxman (D-Los Angeles). “It appears that EPA’s recent plywood rule downplayed or disregarded scientific information that the World Health Organization finds to be credible and strong.”
A prominent epidemiologist went further.
“If the leading international agency on cancer has reevaluated the data and declared formaldehyde to be a human carcinogen, it no longer seems right for the EPA and the White House to ignore these data,” said David Michaels, who was assistant Energy secretary for environment, safety and health in the Clinton administration.
The World Health Organization panel deliberated last week in Lyon and planned to publish a treatise in the next few months.
Formaldehyde occurs naturally in the environment and is produced in large scale around the world for use as adhesives and binders for wood products, pulp, paper and other manufactured products.