LITMIR.BIZ

Скачать книгу

of Air Pollution, told the conference that he wanted to make some “comments based on my listening for the last two days, having some discussions with some people in and outside the room, and my experience as a physician who has spent most of my life in public health work.” While he did not “mean to get into any acrimonious debate” and was “not intending to impugn anybody’s work,” Heimann confronted Kehoe directly. He announced that he felt compelled to “point out that there has been no evidence that has ever come to my attention . . . that a little lead is good for you.” It was, he went on, “extremely unusual in medical research that there is only one small group and one place in a country in which research in a specific area of knowledge is exclusively done.” Kehoe’s experiments that were said to provide evidence that lead from gasoline and other airborne sources presented little danger to people would need “to be repeated in many other places, and be extended,” before the scientific community lent them legitimacy. He also questioned Kehoe’s assertion that no danger existed below a blood lead level of 80 micrograms per deciliter, a reading that often corresponded with convulsions in adults working in lead-paint and other factories.⁴⁷

      In addition to presenting a clear challenge to the paradigm that Kehoe and the lead industry had carefully propagated for more than thirty years, participants at the 1965 conference challenged the very basis of industrial toxicology as it then existed. In the words of one attendee, lead toxicology put “the whole field of environmental health . . . on trial.”⁴⁸ Scientists had for too long accepted the industry argument that if workers who were exposed to various toxins, including lead, did not show symptoms of disease, the public had little to worry about, since consumers were exposed to much lower levels of these materials. A broad public debate was needed on what was, and was not, an acceptable risk; industry assurances of safety were not sufficient. The “public at large [needed to] be given a rational basis on which to decide . . . that lead should or shouldn’t be taken out of gasoline, that pesticides should or shouldn’t be used in various situations, that asbestos should be curbed.”⁴⁹ Indeed, in the coming years, the field of lead toxicology would be transformed to address just such concerns.

      In the mid-1960s, Kehoe was just one of several industry supporters repeating the mantra that the critical measure of lead’s toxicity was the worker in the plant. Studies had shown that lead workers on average were absorbing less lead than earlier in the century, and industry touted this as proof that the public was protected as well. When Senator Edmund Muskie (D-ME) held hearings on air pollution in mid-1966, the LIA campaigned to undercut any criticism of the lead industry that might emerge. In addition to preparing articles and press releases to encourage “positive stories regarding lead and its uses,” the LIA developed testimony for the hearings.⁵⁰ Felix Wormser, retired but still on retainer for St. Joseph Lead Company, testified on behalf of the LIA, asserting that “vast clinical evidence” showed that “the general public is not now, nor in the immediate future, facing a lead hazard.” Leaded gas posed no harm at all and a vast literature and much research confirmed this view, he claimed.⁵¹ Kehoe went on to testify that “the evidence at the present time is better than it has been at any time and that [lead] is not a present hazard.”⁵² His commitment to an 80 µg/dl blood-lead-level threshold blinded him to the possibility that, whatever this standard’s adequacy for protecting adults, children, because of lead’s effect on their developing neurological systems, might be at much greater risk at lower levels.

      Though Kehoe’s position aroused skepticism among some in scientific and political arenas, it still found considerable acceptance among the general public. Kehoe himself had told Muskie’s committee that his laboratory was “the only source of new information” about lead in the factory and the environment and had “a wide influence in this country and abroad in shaping the point of view and activities . . . of those who are responsible for industrial and public hygiene.”⁵³

      Storm clouds were appearing on the horizon, however. In 1967, the LIA commissioned the Opinion Research Corporation to conduct a survey of “public knowledge and attitudes on lead.” The survey 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

Скачать книгу