What’s Science Got to Do with It?

Acording to the Pew Research Center, a little less than half of Americans believe global warming is a result of human activity, although a few more concede that there may be warming from other causes. Some prominent opinion leaders have denounced global warming as a “hoax.” Meanwhile, a NASA website notes that upwards of 97 percent of climate scientists believe warming by carbon forcing is a fact. It’s likely that the rest of the professoriate, in other disciplines, shares similar views.

Within that super-consensus are many unsettled issues, notably how much will temperature rise and how fast. Many science types (including me) who believe that global warming is proven fact are “Sunday drivers” when it comes to climate models or methods of integrating temperature measurements into a central tendency—we have formed our opinions based on simplified statements by authoritative scientific bodies. Once you have accepted the paradigm (see Thomas Kuhn), apparently contradictory phenomena, such as a polar vortex over the northeastern U.S., are explained away (correctly) rather than used to challenge the prior view.
Now I return to formaldehyde for the third time. Risk assessment and its application continue to evolve with EPA’s December 2016 rule on testing formaldehyde emissions from composite wood products. It’s worth assessing the authority of the science behind this rule by describing the processes of the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP), and the National Academy of Sciences (NAS). IARC REVIEWS In 2004, an IARC working group raised the classification of formaldehyde to “known to be carcinogenic to humans.” The full Monograph 88 was posted in 2006, noting sufficient evidence in humans for certain upper airway cancers, and “strong but not sufficient evidence for a causal association between leukemia and occupational exposure to formaldehyde.” The epidemiological evidence was mainly the National Cancer Institute (NCI) cohort, which showed exposure-response for the upper airway cancers and leukemia, as well as some scattered studies showing an association with leukemia in embalmers. The finding about leukemia was important because leukemia is more prevalent than the upper airway cancers and therefore would translate into much higher observed carcinogenic potency and, hopefully, much stricter controls.
The IARC monograph program is generally considered the most authoritative scientific opinion on the carcinogenic potential of chemicals and exposure circumstances. IARC working group members are appointed by the secretariat, which is in turn governed by the World Health Organization, through a nomination-and-public-comment process. Working group members write all parts of the monograph. These texts are commented on by the other members and the staff, and then edited during a 10-day meeting in Lyons, France, and conclusions voted on. (I’ve served on three working groups; the meeting is “full-contact” peer review.)
Working group members are active researchers with knowledge of the exposures being considered. They are mostly academics, but some are from governmental research agencies. All are free from conflicts of interest. None are compensated by IARC for their time.
The Monograph 88 group also included an “invited expert” from the Chemical Industry Institute of Toxicology (CIIT). Invited experts are active in the relevant area but have conflicts of interest. They participate in discussions in committees and plenaries but don’t write text or vote.
Also in 2004, a series of papers spit-balling the IARC classification began to appear. These papers were sponsored by the Formaldehyde Council. One was a complete reexamination of the NCI cohort based on the full data set provided by NCI to a well-known university-based professor funded by the Formaldehyde Council. This paper concluded no evidence of risk for formaldehyde at either cancer site. Additional sponsored mechanistic studies questioned whether sufficient inhaled formaldehyde was absorbed into the blood to account for leukemia arising from bone marrow, although other independent studies identified genetic damage in circulating blood cells in exposed workers.
FRANK MIRER, PhD, CIH, is a professor in the CUNY School
of Public Health in New York. He can be reached at (212) 396-7782 or