revealed that 42 percent of the public identified “lead among ten substances as being harmful to health.” In fact, lead ranked second only to carbon monoxide in Americans’ perceptions of risk. The only solace the LIA could garner from the survey was that the public relations damage seemed, for the moment, to be contained: in the public mind, lead’s danger “seems to be associated primarily with paints.” Only 1 percent of those surveyed identified leaded gasoline as being “harmful to health.” Still, few people polled could identify any positive uses for lead, the LIA learned, a point that did not augur well for the future. That so many people believed that lead posed a health problem meant, in the words of Hill & Knowlton, the lead industry’s public relations firm, “they could be expected to be receptive to—or are, in effect, preconditioned for—suggestions that lead emissions into the atmosphere may constitute a health hazard.” Hill & Knowlton warned that with increasing attention to air pollution the public could soon view leaded gasoline as a threat to their health.54
As with early concerns about lead paint, the industry made it its business to promote the metal as good for society and to challenge assertions that lead in the atmosphere was dangerous. In a letter to its members in 1968, the LIA extolled the importance of its new publication, Facts about Lead in the Atmosphere, which it described as “one phase of the LIA’s efforts to refute the many claims made in the technical journals and the lay press that lead in the ambient air is reaching dangerous levels.” Such claims were “entirely without foundation,” the association asserted.55 Just as the National Lead Company, producers of the Dutch Boy brand of lead pigment and paint, had sponsored ads in the century’s opening decades, bragging that “Lead Helps to Guard Your Health,” among other supposed benefits, the LIA called lead “an essential metal that is too commonly taken for granted by the public.”56 The uses for lead were now of a decidedly more modern and technological nature, though. It was used as “the basic ingredient in the solder that binds together our electronic miracles and is the sheath that protects our intercontinental communications system. It is the barrier that confines dangerous x-rays and atomic radiation. It is sound-proofing for buildings and ships and jet planes.” And, it was, of course, the major component of batteries and an ingredient of the gasoline that ran the nation’s automobiles.57
Perhaps more than any other figure of the middle decades of the twentieth century, Clair C. Patterson, a geochemist at the California Technical Institute who had trained at the University of Chicago and had worked on the Manhattan Project during World War II, challenged the dominant paradigm of industry-sponsored lead researchers and the control that the LIA exercised in how lead was perceived. Among the many articles Patterson wrote, one that he submitted to the Archives of Environmental Health in 1965 particularly outraged Robert Kehoe.58 Patterson’s research challenged their belief that lead was present in only trivial amounts and had always been present at about the same level in the environment. Although both Robert Kehoe and fellow researcher Joseph Aub were asked to review Patterson’s paper before its publication, only Kehoe was willing to critique it directly.
In the article, Patterson documented the extensive pollution caused by the growing use of lead in the wake of the Industrial Revolution.59 He had taken core samples of ice from the polar ice cap and measured them for metal content. The increase of lead over time in the core samples from Greenland paralleled the increase in lead smelting and, what was more telling, the consumption of leaded gasoline. The lead concentration of the ice had risen 400 percent in the two hundred years from the mid-eighteenth to the early twentieth centuries; but in just the ensuing twenty-five years, the period when leaded gasoline became the standard fuel for the exploding automobile industry in Europe and America, it rose another 300 percent.60 Patterson estimated that the average level of lead in the blood of Americans was about 20 µg/dl, well below what in the early 1960s was considered the “danger point,” 80 µg/dl, but still startling.61 (Today, as we have seen, the Centers for Disease Control defines 5 µg/dl as “elevated.”) In this, Patterson was directly contradicting Kehoe’s long-standing argument that humans had been adapted to roughly current levels of lead for centuries.
Far from it being normal for Americans to have such elevated levels, Patterson claimed that most Americans bore an unnatural, and potentially unhealthy, amount of lead in their bodies.62 Unlike earlier lead researchers, he was coming at the issue of lead poisoning from outside the small world of lead toxicologists who had largely depended on industry to support their research. It was as important, from industry’s point of view, to tarnish the credibility of this “outsider” as it was to rebut the specifics of his argument. With an attack on Patterson’s work, the industry began a campaign—which continues to this day—to undercut the findings of researchers who have dared suggest that low-level lead pollution has subtle impacts on the general population’s health and specifically on children’s mental development.
Kehoe worried that so many draft copies of Patterson’s paper had already circulated that without a formal channel for rebuttal, Patterson’s position might gain greater and greater credibility through word of mouth alone. In the end, Kehoe supported the Archives of Environmental Health’s decision to publish the piece, a move that historian Christian Warren ascribes to Kehoe’s recognition that its publication was inevitable, and to his hope to thus obligate the journal to make room for a subsequent detailed critique.63
In addition to questioning Patterson’s credentials, methodology, and interpretation of the data, his critics were most concerned about his conclusion that “the average resident of the United States is being subjected to severe chronic lead insult.”64 Through his argument, Patterson was undermining the industry view that relatively low levels of exposure were harmless and that the only Americans at risk were workers exposed to high levels. He was questioning the industry view that one was either acutely lead poisoned or one was essentially unaffected by the substance.65 Right after the publication of Patterson’s 1965 article, Donald G. Fowler, the LIA’s director of health and safety at the time, took issue with Patterson’s “assertion that lead pollution in the air has reached ‘alarming’ proportions.” Fowler dismissed the findings as “based on his [Patterson’s] own geological studies . . . and his own interpretive extensions upon these studies into non-geological fields.” Patterson’s work, he claimed, ignored “the recognized body of clinical and biological evidence” and was “unsupported by any medical evidence.” Fowler went on to declare that “lead is not a significant factor in air pollution” and “the public can rest assured that lead constitutes no public health problem.”66
FIGURE 2.Lead (Pb) deposited from leaded gasoline in U.S. cities, 1950-1982. Gasoline was a main source of lead that damaged many, particularly urban, children until the 1980s. The amount of lead in gasoline was gradually reduced from 4 grams per gallon to 0.1 gram per gallon in 1986. It was finally completely phased out of gasoline for automobiles in 1996. Source: Howard W. Mielke, Mark A. S. Laidlaw, and Chris R. Gonzales, “Estimation of Leaded (Pb) Gasoline’s Continuing Material and Health Impacts on 90 US Urbanized Areas,” Environment International 37 (January 2011): 248-57, available at www.sciencedirect.com/science/article/pii/S016041201000156X.
Patterson’s critique of lead’s ubiquity and its potential danger to the public came at a critical time for the industry. Historically, lead pigment had been the most economically significant market for lead producers, but it had begun declining in importance as latex and titanium pigments increasingly captured market share. As automobile sales mushroomed with the economic boom following World War II, the auto industry and the producers of batteries and leaded gasoline supplanted users of pigments as the major buyers of lead. Between 1940 and 1960, despite less frequent use of lead in interior paints, lead consumption increased from about 600 short tons to approximately 1,000 short tons per year. During this period, lead for use in gasoline increased eightfold, from about
