Reducing toxic risks

In Deceit and Denial, Gerald Markowitz and David Rosner provide a carefully documented history of the rapid growth in the use of toxic substances by U.S. industry, juxtaposed against the tragic story of the much slower growth of scientific knowledge and public information about their risks. The authors focus on two illustrative cases–the use of lead in a variety of consumer products and the use of vinyl chloride in plastics–and they raise important policy questions. When such substances are introduced, how can public authorities foster expeditious and objective research on health effects? If health effects remain uncertain, when do scientists and manufacturers have an obligation to alert the public to possibilities of risk? More broadly, should government adopt a precautionary principle that forbids the introduction of new substances until they are proven safe?

Unfortunately, this is also a book dominated by villains and heroes. The lead and plastics industries stand accused of systematically hiding information about the toxic characteristics of their products for decades, manipulating science, engaging in false advertising, and generally misleading the public. The authors contend that such deception is typical of U.S. industry: “Lying and obfuscation were rampant in the tobacco, automobile, asbestos, and nuclear power industries as well,” they write. Government regulators, public health authorities, environmental groups, and journalists are the heroes who brought knowledge to the public and ultimately restrained industrial use of the toxic substances. But beyond pointing to this perceived interplay of forces, the authors do not attempt to answer most of the questions they raise. They simply call for better public access to industry research about toxic chemicals and raise the idea of prohibiting the marketing of new chemicals until they are proven safe.

In developing their cases, the authors–who are forthright in acknowledging that they have been employed by plaintiffs’ lawyers as expert witnesses and have gained access through those relationships to many of the documents used in the book–paint with a remarkably broad brush. They maintain, for example, that “Industry was well aware of the dangers of lead throughout the nineteenth century,” adding that trade associations have damaged the nation’s democratic institutions and that industry’s calls for more scientific evidence have often served as a stalling tactic.

The simplistic character of this diatribe does not do justice to the importance and complexity of the policy issues highlighted by these valuable histories. One is struck by how early scientists suspected and publicized possible links between exposure to lead and workers’ health problems, as well as by how long it took for consensus to emerge about the character and seriousness of those risks. In the early years of the 20th century, lead had gained wide use in the pipes, canned goods, dishes, and other conveniences eagerly sought by increasingly urban and prosperous U.S. citizens. By 1908, Alice Hamilton, a physician associated with Hull House in Chicago, was reporting on studies that linked exposure to lead with miscarriages among female factory workers. Government action followed relatively quickly. A decade later, congressional committees, public health authorities, organizations representing workers, and companies themselves took steps to protect workers from exposure to high concentrations of lead.

But understanding the long-term effects of low-level exposure to lead and informing the public about this risk took much longer. Just as workers began to receive protection, automobile companies added tetraethyl lead (ethyl) to gasoline in order to eliminate engine knock. A blue-ribbon panel in the mid-1920s recommended regulation of leaded gas but concluded that evidence was insufficient to warrant banning its sale. Similarly, scientists began to link lead-based paint to lead poisoning in the 1920s and 1930s, prompting some companies and consumer groups to discourage its use on children’s furniture and toys. It was not until the 1960s, however, that scientists agreed on the long-term neurological effects of inhaling or ingesting relatively small quantities of lead from paint and adopted a uniform definition of what constituted lead poisoning in children.

By the time government authorities acted, markets already were changing to reduce lead use. When cities began to regulate lead-based paint in the 1950s, zinc had replaced lead as the primary pigment in paint, and industry was phasing out the use of lead in interior paint. Federal action followed city and state action. It was not until 1971 that the federal government banned paints with more than 1 percent of lead for use in interiors and on some exterior surfaces of homes built with federal funds. As scientific evidence was debated and regulation grew, some companies and trade associations financed vigorous advertising campaigns that touted the virtues of lead-based paint. The authors consider this shameful.

A similar pattern characterized the introduction of vinyl chloride in the manufacture of plastic wiring, pipes, and inexpensive replacements for wood and metal. Identification of acute effects on workers was relatively rapid, whereas scientific understanding of the problem and public access to information concerning long-term risks of low exposure proceeded slowly. The authors retrace the long road from the development of early safety standards for workers in the 1930s to increasing evidence of links of low levels of exposure to cancer in animals in 1970s and finally to understanding of cancer risks to consumers from drinking alcohol and other liquids from certain plastic containers.

But what to do?

Throughout these histories, the authors emphasize their dominant themes: Most research was financed by industry; health effects on workers received far more attention than effects on the general public; industry trade associations persisted in advertising the positive qualities of their products while scientific evidence accumulated concerning their risks; industry sometimes hid evidence from workers and government officials; and the increasing sophistication of labor representatives, environmental groups, and public health authorities in assembling scientific evidence was critical to efforts to tighten policy.

What the authors think should be done about all this is not clear. On the one hand, they seem to be arguing for marshaling more objective research to identify toxins that threaten public health and safety. On the other, they suggest that calls for more research delay needed regulation. They raise the prospect of making policy by the precautionary principle of proven safety before use, but fall short of fully embracing this principle. The only firm recommendation is for better public access to information.

In fact, the cases do not support the idea that industry speaks or acts in unison when deciding whether and how to use toxic substances. In these situations, as in many others, competitors have varied interests that policymakers can take advantage of to improve public health. Makers of lead paint competed for market share (unsuccessfully) with makers of alternative paint mixtures even before the government took action, in part because of mounting public concern. Decades before the ban on leaded gas, a competitive battle raged between producers of leaded and unleaded gas. Makers of unleaded gas called attention to possible health effects of leaded gas, and makers of automobiles gradually abandoned their alliance with the lead industry as new technology reduced the agent’s benefits in promoting efficient combustion. Sometimes companies did exercise self-restraint. The Ethyl Gasoline Corporation stopped the production of leaded gasoline until scientific issues were resolved, after a government-sponsored conference heard evidence about possible health effects. Plastics manufacturers called for more attention to the development of safety standards than their trade association was willing to support, and the companies ultimately formed a new association.

The authors’ view that industry is a deceitful monolith keeps them from addressing some of the public policy questions that urgently need attention. Determining the health effects of toxic substances and taking appropriate regulatory action remain formidable challenges. Analytic methods continue to improve, enabling neurologists and toxicologists to measure ever smaller amounts of toxins in the bloodstream. But scientists also increasingly understand that workers and members of the public have variable responses to toxins. Establishing causal relationships remains problematic, many widely used chemicals remain incompletely tested, and determining the safety of a single chemical can cost hundreds of thousands of dollars.

One question that needs attention is how to inform the public about scientific uncertainty in estimates of health and safety risks. Congress decreed in 1986 that manufacturers disclose their discharges of toxic chemicals facility by facility and chemical by chemical. But today, companies still report their discharges only in total pounds, which tells community residents little about risk or scientific certainty.

Such issues are not unique to communicating the risks of toxins. The federal government’s recently adopted disclosure system to inform the public about the likelihood that specific models of sport utility vehicles will roll over uses probability ranges to rank vehicles. The Internet, of course, offers new opportunities to layer information to provide citizens with access to narratives describing scientific uncertainty. Regulators might also create standardized graphics to signal whether scientific uncertainty is high, medium, or low, and tell something about its character.

This is a book to be read with caution. Rosner and Markowitz have performed a valuable service by collecting these histories, but have done a disservice to their own work by focusing mainly on industry deceit and ignoring many of the important questions that their narratives raise.