“Nuisance Dust”: Unprotective Limits for Exposure to Coal Mine Dust in the United States, 1934–1969

Abstract

I examine the dismissal of coal mine dust as a mere nuisance, not a potentially serious threat to extractive workers who inhaled it. In the 1930s, the US Public Health Service played a major role in conceptualizing coal mine dust as virtually harmless. Dissent from this position by some federal officials failed to dislodge either that view or the recommendation of minimal limitations on workplace exposure that flowed from it. Privatization of regulatory authority after 1940 ensured that miners would lack protection against respiratory disease. The reform effort that overturned the established misunderstanding in the late 1960s critically depended upon both the production of scientific findings and the emergence of a subaltern movement in the coalfields. This episode illuminates the steep challenges often facing advocates of stronger workplace health standards.

SETTING EFFECTIVE OCCUPA-tional health standards has always been a tortuous process in the United States. Creating regulations to prevent occupational disease has almost invariably involved protracted controversy between clashing interests. For the past four decades, lengthy battles have raged over diverse hazards in the main forum for setting standards, the Occupational Safety and Health Administration. The compromises resulting from these adversarial proceedings have generally fallen short of the goal of guaranteeing that American workers will not suffer significant adverse effects of the conditions present in their working environment.¹

In coal mining, an especially dangerous industry, the regulatory conflicts over prevention of work-induced respiratory disease have fit within the overall pattern. The latest round of rule making has moved at a glacial pace. In 1995, the National Institute for Occupational Safety and Health marshaled an abundance of scientific findings to recommend lowering the permissible level of exposure to coal mine dust, revisiting a standard that had been unchanged since 1972. In 1996, the Mine Safety and Health Administration began to revise the dust standard to incorporate this recommendation. After 16 years of intermittent deliberations, implacable opposition has ensured that the proposed improvement has still not become a final binding rule.²

Even worse than stalemate, however, is a decisive resolution that makes a false promise of protection. I examine the first American efforts to find a safe level for human exposure to coal mine dust, efforts that quickly culminated in such a false promise. In the mid-1930s, the US Public Health Service (PHS) offered an indicator of acceptable dustiness in the working environment of coal mines. This unprecedented venture, together with subsequent analytical exercises proceeding from similar premises, supported the unfortunate characterization of the mixed particulate matter in coal workings as a mere nuisance, not a serious hazard. Although the weak limit reflected in part solicitude for the economic interests of mine owners, I explain the inadequacy of this indicator primarily in terms of scientific and technical experts’ imperfect understanding of the dust hazard.

The remarkable departure here was the energetic, albeit short-lived, bureaucratic initiative exhibited by the PHS. Prior to the end of the 1960s, the federal government had only a marginal role in safeguarding working conditions. But in this instance, the PHS used its superior capabilities for conducting field research to mount an exceptional intervention. This field study brought forth an influential recommendation as to the permissible level of exposure to coal mine dust. Despite its inadequacies, this guideline survived to shape American policy and practice in coal extraction for a third of a century. The recommended limit persisted largely because it appeared to rest on sophisticated epidemiological research by reputable investigators.

Reliance on this illusory safeguard, and the broader notion of the innocuousness of coal mine dust, led to tragic consequences. An epidemic of dust-induced chronic respiratory disease afflicted much of the workforce in American bituminous and anthracite coalfields in the mid-20th century. By 1969, the US Surgeon General conservatively estimated that at least 100 000 current and former miners suffered from the condition variously called coal workers’ pneumoconiosis, anthraco-silicosis, miners’ asthma, or black lung. The cumulative incidence of this incurable disorder from the 1930s through the 1960s amounted to far more than 100 000 cases. Authorities did not prevent a major preventable public health tragedy. Although there were many reasons for this failure of public policy, the widespread belief that particles of coal were a virtually harmless nuisance and no real threat to the well-being of those long exposed to them contributed significantly to making this tragedy. The promulgation of a quantitative standard of safe exposure by scientific authorities served to reinforce the legitimacy of the dominant misconception.³

The primary concern here is the genesis of this standard. I aim to clarify why it arose when it did and why it took the specific value that it did. Answering these questions illuminates the emergence of an essentially dismissive interpretation of the predicament of breathless coal workers. Focusing on the embryonic interval in the 1930s and early 1040s, I devote less attention to the subsequent deliberations over permissible exposure to this hazard. For the post–World War II period, one dominated by the voluntarist American Conference of Governmental Industrial Hygienists (ACGIH), the existing historical literature provides considerable insight that applies to this particular regulatory problem. Certainly, previous studies of the ACGIH system have brought into view the often arbitrary nature of private rule making. This investigation focusing on the heretofore unexamined earlier interval suggests that arbitrariness in the setting of acceptable limits on workplace health hazards, at least in the case of particulate matter in coal mines, predated the emergence of the ACGIH regime.⁴

REDUCTIONIST SCIENCE IN A SICK INDUSTRY

The scientific context in which the coal mine dust standard arose was dominated by a reductionist perspective. In the late 19th century, professional and lay observers generally recognized anthracosis as a significant occupational disorder. After the turn of the 20th century, however, this condition came to be considered benign, a mere discoloration of lung tissue. Although a full discussion of the exculpatory process is beyond the scope of this article, the critical argument that came to hold sway in the biomedical community was that, compared with silicosis, damage from coal dust did not manifest itself dramatically enough on x-ray. By 1929, a panel of experts reporting to the Industrial Hygiene Section of the American Public Health Association on the pneumoconioses devoted all its attention to silicosis. This committee even noted a controversial therapy for that disease:

There is some disagreement in regard to the suggested treatment by administration of some non-silicious dust, such as coal dust, that is apparently harmless and will assist in removing the harmful dust.

Fixation on silicosis thus served not only to divert attention away from but also to deny the existence of coal workers’ pneumoconiosis.⁵

Economic collapse set the immediate context of the development of the coal mine dust limit. The Great Depression devastated the American coal industry, which had already suffered from excess capacity through much of the 1920s. Whereas bituminous extraction had employed almost 700 000 in 1922, barely 400 000 remained on the payrolls 10 years later. Thousands of soft-coal mines closed between the mid-1920s and mid-1930s. A similar pattern afflicted the anthracite side of the industry. To exacerbate further these cyclical difficulties, coal faced a dire long-term challenge from other forms of fuel, especially petroleum, which gobbled up market share in home heating and industrial uses.⁶

After 1930, many disabled coal workers desperately scrambled for respectable public assistance. Miners and their union, the United Mine Workers of America, proposed unemployment insurance, job-creating public works projects, and old age pensions. Their proposals for social insurance centered on workers’ compensation reform to extend benefits to victims of dust-induced illness. In Pennsylvania, where some paroled prisoners chose to remain incarcerated rather than face the depression, demands for social provision were especially insistent in the coalfields, the scene of wholesale dislocation. Besides demonstrations and ad hoc organizing (often led by communists) among the jobless masses, the state witnessed increasingly bold forms of expropriation as bootleg operations involved tens of thousands of unemployed miners in the systematic theft of coal from dormant mines. As elsewhere, many displaced workers with respiratory disability filed damage suits against their former employers.⁷

Amid this tumult, Pennsylvania’s governor, Gifford Pinchot, in mid-1932 appointed a commission to consider broadening the workers’ compensation statute to encompass occupational diseases. In particular, Pinchot charged the commission with contemplating the compensability of the pneumoconioses—silicosis, asbestosis, and anthracosis (or, as it was commonly known in the vernacular, miners’ asthma). Coal operators warned the gubernatorial panel of the precarious plight of their industry, both threatened by low-cost mining districts south of the Ohio River and burdened with an aging workforce. One anthracite firm advised the commission that compensation for miners’ asthma would cost it more than $2 000 000 a year. The prospect of assuming a sizable share of the human costs of production deeply troubled the coal industry.⁸

The commission’s survey of physicians in the anthracite region brought the operators no comfort. Seventy-eight practitioners estimated that over one fifth of the hard-coal workforce suffered either partial or total disability from miners’ asthma. Despite the evidence of the work-induced nature of the coal workers’ respiratory ailments, the report of the Commission on Compensation for Occupational Disease in March 1933 dodged the question of providing for pneumoconiotic coal workers. Instead, the commission urged the governor to bring in the federal PHS to determine “the exact nature and prevalence of chronic incapacitating miners’ asthma.” Pennsylvania officials did not ask Washington for advice on setting exposure limits to prevent either exacerbation or further occurrence of this disorder.⁹

Between May and September of 1933, federal investigators examined 2711 miners in three mines in the hard-coal area around Wilkes-Barre, Pennsylvania. Most remarkably, despite the absence of any mandate, the epidemiological team headed by physician Royd R. Sayers took it upon themselves to advance a different conceptualization of the illness under consideration. Brought in to assess miners’ asthma or anthracosis, Sayers and his colleagues applied the conventional wisdom of the time and reduced the issue to that of silicosis. To be sure, a small share of coal miners encountered silicious rock in sufficient doses to incur that disorder. And as David Rosner and Gerald Markowitz, among others, have shown, silicosis was in its own right a terrible scourge in several American industries at this time. But in both soft- and hard-coal extraction, by far the larger hazard arose from the universally encountered mixed dust in which fine particles of coal itself comprised the bulk of the mixture. Both in its preliminary report to Pennsylvania officials in 1934 and in its widely disseminated final report two years later, the PHS dismissed the threat of nonsilicious mineral dust. Sayers and his colleagues simply swept aside the more common risk in a reductionist preoccupation with silicosis.¹⁰

“SAFE LIMITS OF DUST EXPOSURE”

The federal officials went beyond their immediate charge in another important respect by conducting extensive dust monitoring. The PHS suggested that its correlation of medical findings with the environmental data had yielded evidence of “safe limits of dust exposure.” On the basis of almost 300 dust samples drawn from varied work locations, the PHS concluded that

employment in an atmosphere containing less than 50 million dust particles per cubic foot [of air] would produce a negligible number of cases of anthraco-silicosis when the quartz content of the dust was less than five percent.

For dust mixtures in which silica exceeded 5%, the agency advised more stringent limits. For example, for coal workers whose jobs regularly involved cutting through silicious rock (averaging about 35% free silica), it recommended a limit of five million to 10 million particles per cubic foot (mppcf) of air.¹¹

The national government’s figure of 50 mppcf for workers exposed to little quartz dust appears to have been an entirely new indicator. My research has uncovered neither private suggestions for nor public commitments to this level of protection prior to 1934. The origins of this figure remain obscure. It was certainly not straightforwardly induced from the data gathered in eastern Pennsylvania in 1933. Indeed, the only plain evidence of a safe level of exposure emerging from that study came from a control group of workers who inhaled, on average, less than five mppcf. The PHS reported that it had not diagnosed a single case of anthraco-silicosis among the group exposed to that level of dustiness. In the next lowest category of exposure, in which air contamination averaged between five and 34 mppcf, the PHS found no guarantee of freedom from respiratory disease. Eighteen of 376 employees in that bracket had pneumoconiosis. How 50 mppcf emerged from this study as the “threshold dosage” becomes even more unclear in light of the PHS’s own vague reasoning on this matter, as well as its admission that it had not designed this investigation to generate sufficient data on low-intensity exposure:

The number of men exposed to relatively small quantities of dust containing less than 5 percent free silica was too small to afford reliable information for determining the quantity of dust which could be tolerated with no adverse effect upon health. However, from the data available, it appeared reasonable to assume that employment in an atmosphere containing less than 50 million dust particles per cubic foot would be associated with a negligible number of cases of anthraco-silicosis when the quartz content of the dust was less than 5 percent.

Under the circumstances, it might have been more reasonable to assume nothing, especially when Pennsylvania officials had not requested assistance in estimating exposure limits. In retrospect, another reasonable alternative would have been to conclude that five mppcf represented the best available value.¹²

One factor in arriving at its chosen recommendation may have been federal investigators’ awareness that for most of the workers studied, attainment of even the 50-million-particle limit would have represented a major improvement in conditions. Excluding the rock workers, the majority of the miners under study were breathing more than 50 mppcf. Indeed, about a third were regularly exposed to more than four times that concentration of dust underground, a most unhealthful respiratory risk. Moreover, from other federal dust-monitoring activities in the coal industry, the PHS had a sense that a large proportion of underground workers routinely faced dust levels far exceeding 50 mppcf.¹³

That the federal government even ventured into the realm of suggesting threshold dosages for mineral dusts in coal mines is yet another sign of the hegemonic influence of silicosis at this time. The object of sustained international scientific interest since the turn of the century, silica dust first became the object of standard setting in the South African goldfields. A federal study of lead-zinc miners in Missouri in the 1910s offered a very qualified, preliminary recommendation regarding permissible exposure: 10 milligrams of dust per cubic meter of air. The authors of that guidance explicitly rejected any claim that it represented a threshold of innocuousness. PHS field research in the Vermont granite industry in the 1920s yielded a tentative recommended limit on silica exposure of roughly nine mppcf. As of the mid-1930s, no similar recommendations existed for any other pneumoconiosis-inducing dusts (asbestos, cotton, diatomaceous earth, etc.), again demonstrating the critical influence of experience with silica on coal mine dust standards.¹⁴

With federal experts delimiting the problem to silicosis, political leaders in Pennsylvania found themselves with a more manageable policy issue. The state legislature in 1937 amended the workers’ compensation law to allow benefits for that small share of coal miners who could demonstrate, essentially by radiographic evidence alone, that they had classic silicosis. Freed of the lion’s share of the disease costs of production, the Pennsylvania coal industry managed to revive with the wartime boom commencing at the end of the decade. The state had contained the mine owners’ difficulty within narrow bounds.¹⁵

DURABLE AUTHORITATIVE GUIDANCE

The PHS guideline on coal mine dust exposure held its place for more than three decades. From the moment of its publication, it was continually invoked as the proper safeguard on exposure to minimally silicious dust. In their widely relied-upon text, Industrial Dust, published in 1936, industrial hygienists Philip Drinker and Theodore Hatch maintained that “both engineering and hygienic common sense support” Sayers and his colleagues’ judgment. At a 1949 meeting of mine inspectors, Hatch made the matter-of-fact claim that the PHS study had “concluded that a dust concentration of 50 million particles per cubic foot will largely eliminate the anthraco-silicosis hazard.” In his capacity as research director of the corporate-dominated Industrial Hygiene Foundation, Hatch sought to deliver reassurance. The 1954 edition of Industrial Dust reiterated an endorsement of these guidelines, based on the percentage of silica in mine dust. Drinker and Hatch did acknowledge the weak evidentiary base underlying these suggestions:

This sliding scale, with no important change, has been rather generally applied to our dust problems in the United States. The quantitative evidence of its accuracy is very questionable, and its value rests essentially upon the considered opinions of various persons thoroughly familiar with dust problems.

Even growing awareness of its flimsiness could not undermine the inertial combination of its authoritative sponsorship and support from potent vested interests.¹⁶

In the decade after 1934, most of the work of disseminating this recommendation fell to the US Bureau of Mines (BOM), which maintained close relationships with coal managers. Although in some respects a captive of the industry it sought to regulate, as William Graebner and Daniel Curran have cogently argued, the BOM displayed a more skeptical attitude toward the dust limits than did the public health agency. When the American Standards Association commenced the process of legitimating and codifying air quality indicators and other permissible exposure limits for mining in 1935, Daniel Harrington, the BOM representative on the standardization committee, objected. Harrington, a veteran mining engineer who had been directly observing dust diseases and their causes for 20 years, deemed it “inadvisable to adopt tentative standards at the present time because nothing definite had been established and experts disagreed among themselves.” The BOM also voiced doubts in its comprehensive review of the pneumoconiosis literature in 1937. That review merely reported the 50-mppcf “finding” from the recent anthracite study without elevating it to definitive status. The mining agency, and particularly the dissident Harrington, continued to look askance at the very notion of safe limits for years to come.¹⁷

The mining bureau’s dissatisfaction with the PHS recommendation grew into outright disagreement. Most strikingly, Sayers himself shifted his position. In 1940, Sayers left the PHS to become the director of the BOM. In this capacity, he initially upheld the limit on dustiness that he had played such a vital role in devising.¹⁸ He then abruptly changed his mind, however, for unknown reasons.

In May 1941, Sayers alerted the West Virginia State Medical Association of the probable deleterious nature of coal dust in its own right and rejected what he now termed the “fallacy of the earlier belief of the beneficial effects of the ‘inert’ dusts, including coal.” Sayers’s paper tellingly failed to cite the heretofore quasi-official sanction for exposing employees to 50 mppcf. Later that year, mining engineer C. W. Owings, a member of Sayers’s staff, told the Mining Section of the National Safety Council that 20 mppcf of coal dust was “probably safe.” Within the hierarchical structure of the BOM, it was most improbable that Owings could make such a declaration without authorization. In all likelihood, he drew upon a recent PHS study of bituminous mining in Utah, which had found minimal anthraco-silicosis among workers long exposed to an average of less than 20 mppcf. After Britain set a standard of approximately 20 mppcf in 1943, the BOM maintained support for the lower threshold, especially in its private communications with mine operators. But the bureau did not stick to a consistent stance. In a 1946 trade journal article, Owings suggested that in especially dusty jobs management should strive to limit concentrations only to 40 mppcf. He presented no evidence that workers exposed to that doubled dose remained free of respiratory impairment but rather implied that this less stringent goal was warranted because it did not place too onerous a financial burden on operations. At the same time, however, Owings defied the dominant view on nonsilicious dust:

Coal dust is often classed as ‘inert,’ but its indirect effects have been cited, and a study of its harmful effect show [sic] that if it is breathed long enough and in dense enough concentrations it may have a harmful effect.¹⁹

The mining bureau more provocatively confronted the reigning orthodoxy on other occasions. In 1950, Owings advised the Mine Inspectors’ Institute of America that his bureau recommended 20 mppcf to prevent not only anthraco-silicosis but also chronic bronchitis and emphysema. These allusions to disabling dust disorders not attributable to silica disturbed mine owners. Earl Maize, safety director of the National Coal Association, sputtered, “I think the statement you made that you do not have to have silicosis to have disability is a little bit like waving a red flag. I think it is a statement that should not be in the record.” Although Maize would have objected to any challenge to silicosis reductionism, he surely found it particularly infuriating that Owings buttressed his assertions by referring to discoveries made in a long-suppressed federal study of dust disease in the bituminous mines of Alabama and Kentucky. The BOM had its rebellious moments.²⁰

On the other hand, when in 1946 Pennsylvania’s secretary of mines, Richard Maize, sought advice on the “allowable maximum” for coal dust, the BOM demurred. Maize insisted on federal guidance: “Until we have some standard established, it appears to me that we are just groping in the dark.” Daniel Harrington responded that neither his bureau nor any other in the world stood “in a position to establish a standard for a maximum permissible number of particles of atmospheric dust in coal mines from either a health or even an explosibility point of view.” This disqualification notwithstanding, Harrington guardedly put forward the 20-mppcf limit and assured Maize that “many mines seem to be able to meet it.”²¹

In an updated edition of its distillation of the pneumoconiosis literature published in 1950, the BOM remained ambivalent about setting any standards, given that “knowledge of pneumoconiosis is incomplete” and given other uncertainties. Rather than make the case for the 20-mppcf value that it had been informally promoting, the bureau set a more ambitious objective:

As no definite, absolutely reliable standards of allowable dustiness are known, obviously the aim in the prevention of dust diseases should be elimination of all dust in the atmosphere where people work.

That lofty aim lay so far beyond the plans and imaginings of the declining coal industry as to have no practical impact.²²

The BOM’s dissent remained for the most part below the threshold of policy discourse. It certainly was not reflected in its own contribution to national regulatory policy, as embodied in the set of rules implementing the federal Coal Mine Inspection and Investigation Act of 1941. In fact, the reticent bureau offered no concrete quantitative limit whatsoever on dust concentrations in the standards it developed in the 1940s. The 1946 code followed by federal inspectors vaguely demanded hazard controls for operations that “raise an excessive amount of dust,” without specifying what constituted an excess.²³

THE NUISANCE TO ACGIH

With the federal government always in a relatively tangential role in policing the underground environment, the states remained the primary regulatory force in the field. Because state-level mining agencies (like other subnational public authorities in the United States, such as state labor and health departments) invariably lacked the capacity to produce their own disease-prevention standards, they depended to a great extent on the ACGIH for guidance. A voluntary, corporate-controlled but quasi-official group of public and private health professionals founded in 1938, the ACGIH sought to translate the latest biomedical knowledge on hazards into recommended threshold limit values (TLVs). No state, however, was compelled to adopt or enforce the TLVs. In general, state regulators imposed no requirements but rather tendered suggestions based on the thresholds. When the ACGIH began to produce annual lists of recommended limits in 1946, its roster of air contaminants embraced the 50-mppcf indication for permissible exposure to coal dust, thereby rejecting the much stricter 20-mppcf level, which had received considerable support from the BOM. The conference apparently took this action without any independent inquiry into its merits. Endorsement of this limit had a strong effect, because of the ACGIH’s stature as the putative national authority on occupational health standards from the 1940s on.²⁴

The ACGIH continued to trivialize the risk of coal mine dust for the quarter century following World War II. In fact, the organization did not even assign this respiratory hazard a specific TLV of its own. Instead, coal dust was lumped into the catchall category of nuisance dust, for which the one-size-fit-all limit of harmless exposure was 50 mppcf. The category of inert dusts (wood, paper, carbon, etc.) covered substances deemed capable of causing no more than discomfort. The initial TLV remained in place despite a flood of scientific evidence from European and American sources after 1950 that demonstrated the adverse results of prolonged heavy exposure to coal particles and the mixed dusts found underground. Perhaps most stunningly, the ACGIH chose to disregard presentations at its own meetings. In an overview of the dust-induced lung disorders at the 1958 session, Henry Doyle of the PHS, along with associates from the BOM and the US Department of Labor, called attention to coal workers’ pneumoconiosis as a discrete disease. Doyle and his colleagues asserted that something new had emerged from the long shadow cast by silicosis: “This disease, caused by coal dust itself, according to British investigators, is an established entity.” The federal officials went on to warn that

in the United States limited information developed mainly by private clinics has indicated that coal workers’ pneumoconiosis, or at least a similar pulmonary condition, exists among coal miners in various sections of the country.

Two years later, the ACGIH heard a paper on the pneumoconiosis situation in the Pennsylvania coalfields that also indicted the nonsilicious hazard. The plain implication of these revelations and of the broader pattern of findings into which they fit was the inappropriateness of the weak TLV that covered mine dust. Yet this information provoked no rethinking of the nuisance notion. With the nuisance-dust association thus persisting, state officials continued to depend upon a false assurance. In 1961, for example, when Roger Powell, an official of the Pennsylvania Department of Mines and Mineral Industries, spoke at the national mine inspectors’ annual convention, he portrayed his agency’s dust-monitoring activity as an effort fixated on preventing silicosis. In that vein, Powell reiterated for his colleagues the ACGIH’s latest announcement of its unchanged dust TLVs.²⁵

The only alteration in the nuisance TLV prior to the 1970s occurred in the mid-1960s, when the ACGIH converted from dust concentrations expressed in terms of the number of particles to concentrations based on the weight of particulate matter per given volume of air. Under the new gravimetric approach, the general limit for all nuisance particulates became 15 milligrams per cubic meter of air (mg/m³). To be sure, for coal dust, this shift lowered significantly the threshold from the 50-mppcf value, to the equivalent of roughly 28 mppcf under the old system. (The foregoing conversion depends on a less than rock-solid assumption about the average weight of each particle.) This improvement still fell short of what the BOM had been privately encouraging more than 20 years earlier.²⁶

BELATED BREAKTHROUGH

At the end of the 1960s, the inappropriateness of applying the nuisance label to coal mine dust at last became widely and inescapably apparent to virtually all in the coal industry. After many delays, in the early 1960s the PHS conducted a national prevalence study of coal miners’ pulmonary disease. The results of this study began to reach the scientific community, political decision-makers, and the general public in 1967 and 1968. Frustrated with the failure of federal officials to share their findings with those at interest, Lorin Kerr of the United Mine Workers’ Welfare and Retirement Fund in May 1967 challenged the biomedical establishment with the assertion that at least 100 000 miners had coal workers’ pneumoconiosis. At that point, Kerr had been quietly maneuvering for two decades to bring the dust-disease plague to light. He had arranged speaking engagements by Jethro Gough, Charles Fletcher, and other leading British investigators. He had relentlessly prodded the PHS to perform its epidemiological duties. However, his scope of action to promote tighter dust standards had been severely constrained by his position within a joint labor–management benefit fund. (And the miners’ union itself had been derelict in addressing the issue.)²⁷

Fresh evidence of widespread occupational disease obviously did not, in and of itself, provide a valid indication of harmless dust exposure. In a methodological step backward from the anthracite investigation of 1933, the 1963–1964 national prevalence study did not gather data on employee exposure, current or past, to dust on the job. Hence, any estimation of either the exposure–response relationship in general or of a threshold dose in particular was impossible. This methodological limitation barred direct application of the PHS’s findings to disease prevention.²⁸

Rather than carry out a unified study that correlated dust-exposure data with health effects, the fractured federal bureaucracy engaged in a much less useful exercise. While the PHS examined miners’ chests, the BOM mounted an extensive program of environmental monitoring. This uncoordinated effort yielded little guidance for setting an appropriate limit on dust exposure. When senior BOM official Earle Shoub reported on this work at the National Safety Congress in 1965, he did refer to the 20-mppcf limit as “one of the widely accepted standards of acceptable dust exposure for bituminous coal miners.” But Shoub avoided making any commitment:

We are not prepared to state … how much silica[-]free coal dust a normal person can breathe over an extended period of time without harm. Also we are not able to state with conviction the relationship between quantity and time.

He hoped that ongoing investigation would yield recommendations that would “provide adequate protection under economically feasible conditions.” At the same session, PHS representative Robert Harris Jr sent much the same tepid message. Neither federal official specified any criteria for what constituted economic feasibility. Indeed, throughout the preceding 30-year period, the concept of feasibility remained a nebulous one, with objective estimates of the costs and technical issues in reaching particular exposure limits absent from the record.²⁹

Nonetheless, the high morbidity disclosed by the epidemiological field work sufficed to help propel a reform process. The subject of direct prevention of dust disease, now termed coal workers’ pneumoconiosis or black lung, became a matter that required federal intervention. The intervention took the form of a uniform national standard for exposure to coal mine dust. This fundamental change in approach reflected the fact that, however flawed, the PHS prevalence revelations cast harsh light on the bankruptcy of the prevailing regime of hazard evaluation and control. This shift to nationalization also involved an initiative to create binding regulations on workplace air contamination, not merely stronger recommendations.³⁰

The first specific proposal for a federal coal mine dust standard came in the waning days of the administration of President Lyndon Johnson, in the wake of a disastrous mine explosion in West Virginia that served to reopen all questions of mine safety and health. On December 9, 1968, the Department of Health, Education, and Welfare (HEW)—an agency whose jurisdiction at that time did not include regulation of working conditions in mining or any other economic sector—proposed that no American miner be exposed to more than three mg/m³ of respirable dust. To justify this plan to cut acceptable exposure by more than 80% in one move, HEW officials cited British experience under mandatory standards “that has shown that reduction of dust to this level will significantly lower the incidence and prevalence of pneumoconiosis.” They added that

US experience had “shown that maintenance of such levels [of dustiness] in coal mine atmospheres is practically achievable.” The proposal carried no assurance that, in fact, three mg/m³ represented a harmless threshold. Instead, Washington conceded that it had “insufficient information to establish precisely the exposure below which no pneumoconiosis would exist.” If HEW’s own recent prevalence study had engaged in analytical, rather than merely descriptive, epidemiology, the national government would have had better information on this question.³¹

In some political circumstances, such an admission of insufficient information would have rationalized further delay, but not in 1969. The sense of urgency generated by unauthorized strikes and mass demonstrations centering in West Virginia and extending, on occasion, across the Appalachian coalfields expedited the drive for meaningful change. In the most dramatic episode in this escalating conflict, more than 40 000 wildcat strikers shut down the mines in West Virginia for three weeks in early 1969 to win workers’ compensation for black lung. Amid angry indictments of the longtime neglect of underground conditions that had disabled so many compensation claimants, demands for disease prevention rose in priority. For the first time, victims and prospective victims took a leading role in promoting ameliorative change.³²

In this turbulent situation, the proposed 3-mg standard came under sharp attack. Mine owners saw this as a radical proposition that would be unduly burdensome. Some defended the current ACGIH limit. Some embraced the Nixon administration’s alternative of 4.5 mg/m³. Others opposed any regulation at all. Seizing upon HEW’s recent concession that it could not vouch for three mg as a safe limit, some black lung activists broached the ultimate limit—a totally dust-free environment. These eradicationists expressed generations of frustration with authoritative mystification of the nature of miners’ maladies and the causes. Their radical position also reflected the optimistic belief in technological prowess widely held in the ebullient 1960s. As the Nixon administration attempted in early 1969 to build a case that 4.5 mg/m³ offered protection against pneumoconiosis, a delegation of miners’ wives and widows confronted Secretary of the Interior Walter Hickel in his office. The angry group invoked the glamorous technological feats of the nation’s space program to challenge this senior government official. One of the widows told Hickel that it was “all right to go to the moon, but conditions on earth need improving, too.”³³

The outcome of mass mobilization in the streets and much congressional maneuvering behind the scenes was a historic breakthrough in health protection for American coal workers. The Federal Coal Mine Health and Safety Act, signed under duress by President Nixon in December 1969, granted an immediate reduction in permissible mine dust exposure to three mg/m³. The act further lowered the standard to two mg/m³ in three years. After a long period of denial and dismissal of coal mine dust as a mere nuisance unworthy of societal attention, the United States had set the strictest dust-control policy for coal mines of any nation in the world.³⁴

The dust regulations contained in the landmark 1969 law substantially improved working conditions underground. In 1980, the National Research Council assessed the implementation of the reform:

In the main, research and industrial personnel in the United States have been very successful in meeting the challenge of a 2 mg/m³ standard. The prophets of doom who saw the standard as a death knell of American coal mining have been proved wrong.

A decade later, even the ex-tremely vulnerable operators of continuous mining equipment were breathing dust concentrations that averaged only approximately one mg/m³. These advances in dust exposure occurred despite a key flaw in the design of implementation: self-monitoring by employers. In the years after federal intervention, the incidence of coal workers’ pneumoconiosis declined in the United States. Nonetheless, room for improvement remained. In a characteristically adamant observation in 1990, Lorin Kerr defended his advocacy of the two-mg/m³ limit in 1969 but maintained that “it should have been one.”³⁵

CONCLUSIONS

My main purpose has been to shed a little more light on the long-standing failure of government to govern with respect to safeguarding American workers. The well-known fragmentation of public authority in the United States served the interests of coal-mine owners well for most of the 20th century with regard to evading responsibility for work-induced disease. From the 1930s on (as in the earlier period not touched upon by this study), uncounted masses of coal workers suffered as a result of crippling divisions—between state and federal administrators, among federal agencies, and between public and private centers of scientific and technical expertise. The fragmented structure of authority virtually guaranteed that no arm of government would either pursue the research to overturn the reigning misconception that coal dust was harmless or use such knowledge to set and enforce real protections against the risk of pneumoconiosis and related pulmonary disorders. In such a forbidding context, it took an extraordinary subaltern upheaval to overturn entrenched misunderstanding and impose a more beneficial limit on dust exposure.³⁶