Knowing Uncertainty for What It Is

For decades, the tobacco and asbestos industries have worked hard to manufacture more than just their products. While aggressively marketing what they make, they’ve also been successfully creating public-information campaigns designed to create uncertainty in the minds of people about claims made against the destructive and lethal characteristics of their products. Though discovery of these efforts has come too late for many of their victims, documents unearthed in lawsuits have revealed concerted efforts to avoid the imposition of government regulation by impugning public health science.

These days, the most well-known (and likely also the best funded) of these campaigns is the one in which the fossil fuel industry manufactures uncertainty about environmental and public health claims raised by scientists and others regarding climate change. When confronted by an overwhelming worldwide scientific consensus on the impact of human commerce in the global warming of the past century, the industry and its political allies follow the tobacco road. Evidence of this was illuminated when Frank Luntz, a leading Republican political consultant, sent a strategy memo to his clients revealed in 2003, and his words were widely circulated among scientists and policymakers. In it Luntz asserted that “The scientific debate remains open. Voters believe that there is no consensus about global warming in the scientific community. Should the public come to believe that the scientific issues are settled, their views about global warming will change accordingly.” (Emphases in the original memo.)

Because journalists often report on political and scientific debates that arise about this issue, they can find themselves transmitting information that conveys this frame of mind to readers, listeners and viewers. In part, this happens when reporters feel obligated to offer space and credibility to skeptical perspectives, even when those who espouse these views are funded and promoted by corporations whose activities disproportionately contribute to the problem, which in this case is global warming. Further, the skeptic’s assertions are often reported without identifying their corporate sponsors or letting readers know the person’s credentials for raising such doubts.

Recognizing the power of a sound bite and memorable phrase, industries responsible for creating what scientists contend are causing the climate to warm often cry “junk science” at the appearance of studies reporting what they regard as unfavorable findings, even when the quality of the research is high. Junk-science advocates allege that many of the scientific studies (and even scientific methods) used in the regulatory and legal arenas are fundamentally flawed, contradictory or incomplete, contending that it would be wrong or premature to regulate the exposure in question or compensate the worker or community resident who might have been made sick by the exposure.

Certainty vs. Inaction

Every first-year public health student is taught how John Snow in 1854 stopped a cholera epidemic in London. During a 10-day period in September during which more than 500 Londoners died from the disease, Snow used a city map to mark the location of each household with a case of cholera. He quickly determined that those who drank from one particular water source were at the highest risk for the disease, and he recommended removal of the handle from the pump supplying drinking water from that source. By using the best evidence available at the time, hundreds of additional deaths were avoided. If government officials in London had demanded absolute certainty, the epidemics might have continued for another 30 years until the cholera bacterium was identified.

In our time, it seems, debate over science is replacing debate over policy, and this can threaten the ability of the government to protect the public’s health and environment. As Snow’s story demonstrates, the desire to establish absolute scientific certainty is both counterproductive and futile. This recognition is realized in the wise words Sir Austin Bradford Hill, a renowned biostatistician, delivered in an address to the Royal Society of Medicine in 1965:

“All scientific work is incomplete—whether it be observational or experimental. All scientific work is liable to be upset or modified by advancing knowledge. That does not confer upon us a freedom to ignore the knowledge we already have, or to postpone action that it appears to demand at a given time.

“Who knows, asked Robert Browning, but the world may end tonight? True, but on available evidence most of us make ready to commute on the 8:30 next day.”

Yet in our time, the wisdom of Hill’s words is being both twisted and ignored. For example, take the case of Philip A. Cooney, chief of staff for the White House Council on Environmental Quality, extending a political hand into the editing of a federal report on climate change to magnify the level of uncertainty. Before his appointment to a top environmental protection job by President Bush, Cooney worked as a lobbyist with the American Petroleum Institute (API), one of the nation’s leading manufacturers of scientific uncertainty. Subsequently he left the White House for employment with ExxonMobil, where his job title might have changed but not his mission.

Another example of tearing down scientific findings in the name of certainty happened with a chemical called benzene, a byproduct of oil production and use, and exposure to it is known to cause leukemia. Recently, a team of U.S. and Chinese scientists confirmed that workers with exposure to benzene (a known human carcinogen) at levels that meet the current workplace standard in the United States have an increased risk of blood disorders. The medical message is clear: The current standard is not protective; it needs to be tighter.

Facing such a specter, the API raised more than $20 million to conduct its own study whose results were expected to, according to internal documents, “establish that adherence to current occupational exposure limits do [sic] not create significant risk to workers exposed to benzene.” But how does API know what the results will be before the study even begins? It’s a common trick of the trade, one that any of the key players in the “product defense” (which is their own term) industry can pull off easily. They are talented experts at subverting science at the behest of their corporate clients, and they hire product defense scientists who won’t deny that a relationship exists between the exposure and the disease, but are quick to conclude that “the evidence is inconclusive.”

It is important for people to understand—and for journalists to help them do this—that our nation’s public health programs will not be effective if absolute proof is required before we act; instead, the best available evidence must be sufficient.But much scientific “uncertainty” about the causes of disease is manufactured, designed to impede the inconvenience and economic consequences of public health protections. For 50 years, tobacco companies employed a stable of scientists to assert (sometimes under oath) that they did not believe there was conclusive evidence that cigarettes caused lung cancer. Scientists paid to manufacture such uncertainty would dissect every study, then highlight flaws and inconsistencies. Less well-known but following the same pattern are the campaigns mounted to question studies documenting the adverse health effects of exposure to lead, mercury, vinyl chloride, chromium, beryllium, benzene and a long list of pesticides and other toxic chemicals.

Manufacturing uncertainty is now so commonplace that it is unusual for the science behind an environmental regulation not to be challenged. Yet it is important for people to understand—and for journalists to help them do this—that our nation’s public health programs will not be effective if absolute proof is required before we act; instead, the best available evidence must be sufficient.

Observing the Strategy

I observed the work of the product defense industry when I served as assistant secretary for environment, safety and health in the Department of Energy (DOE) from 1998 to 2001. In that role, I was the nuclear weapons complex’s chief safety officer, responsible for protecting the health of workers, the communities and environment around some of the most dangerous and polluted sites in the country. One of my chief concerns was beryllium, a lightweight metal vital to nuclear weapons production. Hundreds of weapons workers have developed chronic beryllium disease (CBD), a sometimes-fatal lung disease associated with breathing tiny amounts of the metal.

Beryllium’s victims included not only machinists and others who worked directly with the metal, but also others who were in the vicinity of beryllium work, often for very short periods of time. One accountant had developed CBD after working for a few weeks each year in an office near where beryllium work was underway.

In 1998, when I was appointed by President Bill Clinton, both the Occupational Safety and Health Administration (OSHA) and DOE (whose facilities were not covered by OSHA) were applying a 50-year-old standard for protecting workers from beryllium exposure, a standard that was widely recognized as inadequate. As both agencies began the time-consuming legal process of updating their rules, the beryllium industry mounted what has become a predictable response: They hired Exponent, Inc., one of the leading product defense firms, to assert that there is too much uncertainty in the science on the ability of beryllium to cause CBD to warrant a new standard.

Sharing authorship with product defense specialists, beryllium industry-associated scientists published a series of papers suggesting it was possible that beryllium particle size, or particle surface area, or particle number, are more important than previously thought in the development of beryllium disease. They also raised the hypothesis that skin exposure could play a larger role in CBD risk. The hired guns concluded that, even though the current standard was not protective, more research was needed. They even suggested that once these questions were answered, the new beryllium standard “could easily be among the most complex yet established.”

After reviewing the extensive evidence and taking testimony from industry and independent scientists, DOE concluded that, while more research is always desirable, we had more than enough information to protect workers immediately. Over the industry’s objections, we issued a much stronger standard, reducing the acceptable workplace exposure level by a factor of 10. This new standard, though, applies only to nuclear weapons workers; beryllium-exposed workers in the private sector don’t have the same protection. In 1998, OSHA declared its intention to issue a similar standard to protect workers in the private sector, but dropped beryllium from its regulatory agenda once the Bush administration took over in 2001.

In the past, corporations and public relations firms hired individual scientists as part of their uncertainty campaigns; the product defense industry represents an evolution into specialization. After all, today scientists themselves control many of these firms, and because they understand the workings of science better than the usual public relations person, they are better able to design campaigns that successfully raise questions and promote doubt. As they do so, journalists need to be prepared to ask tougher questions about the evidence they are shown, to inquire about funding behind the “science,” and inform their readers, listeners and viewers about any links they find between those who supported the research and its findings. Until such connections are made visible by journalists and commentators, the uncertainty being manufactured will achieve its goal to the detriment of both science and health.

David Michaels is research professor and associate chairman of the Department of Environmental and Occupational Health at The George Washington University School of Public Health and Health Services in Washington, D.C.