Observational studies as human experimentation: the uranium mining experience in the Navajo Nation (1947-66)

This article evaluates how an observational epidemiologic study of federal agencies in uranium miners became an experiment of opportunity for radiation effects. Navajo miners and communities suffered environmental exposures caused by the practices of uranium mining and milling in the Navajo reservation during the 1947 to 1966 period. A historical review of the state-of-the-art knowledge of the health effects of uranium mining and milling during the years prior to 1947 was conducted. Contemporary prevention and remediation practices also were assessed. An appraisal of the summary of findings of a comprehensive evaluation of radiation human experimentation conducted by the U.S. federal government in 1995-96 (ACHRE) demonstrates that uranium miners, including Navajo miners, were the single group that was put more seriously at risk of harm from radiation exposures, with inadequate disclosure and often with fatal consequences. Uranium miners were unwilling and unaware victims of human experimentation to evaluate the health effects of radiation. The failure of the State and U.S. Governments to issue regulations or demand installation of known mine-dust exposure control measures caused widespread environmental damage in the Navajo Nation.

The work environment impact assessment: a methodologic framework for evaluating health-based interventions

BACKGROUND

A new conceptual framework is needed to evaluate health-based interventions based on the premise that like the environment, workplaces are complex ecologies. The proposed Work Environment Impact Assessment (WEIA) is analogous to Environmental Impact Assessment (EIA), a concept and method developed 30 years ago in the environmental policy arena to evaluate potential consequences of human activity for the natural environment. WEIA entails identifying and evaluating both intended and unintended consequences, or outcomes, associated with a particular intervention. Because the workplace is a complex ecology, changes in one aspect may lead to changes in other aspects. WEIA calls for a systematic and comprehensive approach to the total work environment.

METHODS

To illustrate the utility of WEIA we use this approach to evaluate an intervention to reduce the public's exposure to the pesticide Alar, which had been used on apples until it was withdrawn from the market in 1989.

RESULTS

While this intervention did indeed reduce the public's exposure to Alar, it also led to other unintended consequences, namely new ergonomic hazards for apple pickers, increased stress levels in the orchards for both pickers and growers, as well as new worker, and perhaps public, exposure to potent neurotoxins.

CONCLUSIONS

The goal of using WEIA is not to engage in a risk-risk debate that stalls worthwhile interventions. Rather, we propose that by conducting a Work Environment Impact Assessment, all possible positive and negative "ripple" effects stemming from an intervention can be considered, so that the intervention can be designed to achieve maximum benefit.

Pollution prevention and the work environment: the Massachusetts experience

In 1989, Massachusetts enacted the Toxics Use Reduction Act. The Act defined toxics use reduction, also referred to as pollution prevention, as "in-plant changes in production processes or raw materials that reduce, avoid, or eliminate the use of toxic or hazardous substances or generation of hazardous by-product per unit of product ... without shifting risks between workers, consumers or parts of the environment." The investigators sought to understand to what extent worker health and safety concerns have been integrated into toxics use reduction activities and how these activities have affected the work environment. The authors reviewed 35 published case studies of toxics use reduction in Massachusetts companies and interviewed key personnel including the staff of the Massachusetts Office of Technical Assistance for Toxics Use Reduction. Overall, between 1990 and 1997, Massachusetts companies decreased their use of toxic chemicals by 24 percent and decreased their volume of toxic by-product by 41 percent. In almost 50 percent of the cases analyzed, improved worker health and safety was cited as a benefit of the toxic use reduction projects. Solvents were eliminated or reduced in 63 percent of the cases. Forty-six percent of the companies profiled introduced water-based chemicals in place of more volatile ones; and acids and caustics were reduced or eliminated in 20 percent of the cases. The investigators concluded that toxics use reduction activities have resulted in improvements to the work environment, but that such improvements were rarely a direct concern of these efforts, thus creating the potential for new negative worker health and safety impacts and missed opportunities to coordinate environmental and worker health and safety improvements. The authors recommend that technical assistance agencies and companies better integrate worker health and safety issues and pollution prevention activities.

The convergence of labor and public health: a natural and critical alliance

The reorganization of a Labor Caucus in APHA provides an opportunity to reflect on the community of methods and interests between the public health and labor communities. The nature of both movements is examined and the factors (knowledge base, political will, and social strategy) that define the actions of both movements are addressed. The antagonism between the prevailing political dogma of market individualism and the two movements is also discussed, with special emphasis of the need for strong government involvement to support the functioning of both labor and public health. Important issues that currently affect labor and public health are discussed. Constructive disagreements on policy choices of labor on national health insurance and occupational safety and health are examined. A warm endorsement of a critical alliance of labor and public health is made, and the revitalization of a labor caucus is cordially welcomed.

Sustainable production: a proposed strategy for the work environment

BACKGROUND

In the future, competitive industries will need to design for environment, health and safety as well as for productivity. Although the new areas of pollution prevention and clean production have evolved to address the design of production processes with concerns for the ambient environment, current pollution prevention models do not include explicit concerns for health, safety, and the work environment. The field of occupational health and safety has much to contribute to improve current pollution prevention approaches and solutions.

METHODS

The application of work environment disciplines will need to be expanded from the conventional focus on "end-of-pipe" assessment and solutions, which take the production processes and resulting hazards as a given, to include a new focus on materials selection and process redesign. To make this shift, a new framework called "sustainable production" is proposed. The basic unit of sustainable production is the production process. The framework integrates a focus on the ambient and work environment along with a focus on productivity and the economic viability of the business enterprise in setting production process design parameters.

RESULTS

By shifting the focus of occupational and environmental health and safety from exposure control to process design, sustainable production reduces the likelihood that concerns for health, safety, and the environment will be seen as antagonistic to productivity and economic development. To move a firm toward sustainable production, occupational health and safety professionals will need to participate in interdisciplinary workplace teams that design and build new production processes and that continuously evaluate and redesign existing processes.

CONCLUSIONS

This new strategy requires an expansion of the role of the occupational health and safety professional to include evaluation and redesign of processes that produce goods and services as well as the conventional evaluation of chemical, physical, and biological agents, work practices, and ergonomics. This expansion of occupational and environmental health and safety requires new research to develop the scientific and public policy basis of sustainable production.

Back to the future: sweatshop conditions on the Mexico-U.S. border. II. Occupational health impact of maquiladora industrial activity

Present working conditions in one of the most active areas of the maquiladora system along the Mexico-U.S. border are reminiscent of nineteenth-century U.S. sweatshops. The organization of production is Tayloristic and authoritarian, with detailed division of labor, repetitive simple tasks, and piecework wages. Modern participative management styles are not apparent in the maquiladora setting. This study consists of two separate but interrelated surveys conducted in 1992, one of community leaders and this one of workers in maquiladora enterprises in the towns of Matamoros and Reynosa, Mexico. The community survey evaluated the economic and psychosocial impact of the maquiladora enterprise and was conducted simultaneously to the workers' survey and in the same Mexican towns where the workers lived and worked. The community leaders acknowledged the employment opportunities that maquiladora factories had brought to the region but believed them to have high environmental and psychosocial costs. For the occupational component, a community-based survey of 267 maquiladora workers was conducted. participants were chosen with more than a year seniority in the industry and living in the two Mexican cities surveyed. They responded to an extensive questionnaire given by trained canvassers. The workers' survey found evidence that maquiladora workers (81% female) report symptoms from musculoskeletal disorders related to working conditions. Acute health effects compatible with chemical exposures were also identified. Prevalence of symptoms was correlated with increasing duration of exposure to ergonomic risk factors and qualitative chemical exposure indexes. Other chronic disease was not apparent. The survey demonstrated inequalities in salary, working hours, and safety training between the two communities. Matamoros workers are substantially better paid and work fewer hours per week than Reynosa workers. Most hazards reported in the worker's survey have been well studied in the general occupational health literature with respect to adverse health effects. Therefore, it is recommended that hazard surveillance studies would be more useful towards the goal of prevention than further etiologic studies. Specific recommendations on policy and remediation interventions are also made.

Exposure assessment for a field investigation of the acute respiratory effects of metalworking fluids. I. Summary of findings

The exposure assessment summarized here is part of an epidemiologic study of the acute respiratory health effects of metalworking fluid (MF) exposures. Exposures were measured as the inhalable concentrations of the MF aerosol, a variety of metals and elements, and endotoxin as well as the level of culturable bacteria in the aerosol size fraction less than 8 microns. Bulk samples of soluble MFs were tested for pH, mineral and tramp oil fraction, endotoxin, culturable bacteria, and lipopolysaccharide levels. The MF exposed workers had higher geometric mean inhalable aerosol exposures (0.181 mg/m3) than the MF unexposed workers (0.046 mg/m3). The MF exposed workers had higher geometric mean (GM) airborne culturable microbial counts (102 colony-forming units (CFU)/m3 for bacteria < 8 microns) than the unexposed workers (GM = 14 CFU/m3). Among the unexposed, Bacillus was the predominant airborne species, while among the exposed workers, Pseudomonas predominated. Exposed workers also had higher geometric mean airborne endotoxin levels (GM = 7.1 endotoxin units (EU)/m3) than the unexposed workers (GM = 1.9 EU/m3). Elemental concentrations of iron, chlorine, and sulfur were substantially higher among the exposed workers compared to the unexposed workers. For soluble metalworking fluids, the levels of bulk constituents were examined by three categories of time since the machine sump was refilled with fresh MF (< 4 days, 4-21 days, > 21 days). Univariate analyses of percent oil, pH, culturable bacteria, tramp oil percent, endotoxin, or fatty acid levels all showed no statistically significant changes in level over time.

Atrial fibrillation and sudden death related to occupational solvent exposure

Two cases of atrial fibrillation and one case of sudden death occurred in workers exposed to trifluorotrichloroethane (CFC 113) as a solvent/degreasing agent. This agent and related halogenated hydrocarbons are widely used in industry as solvents and degreasing agents, and have been previously linked to ventricular arrhythmias and cardiac sudden death when inhaled in excessive concentrations. We suggest that occupational overexposure to halogenated hydrocarbons should be considered a potential precipitant for atrial as well as ventricular arrhythmias.

Back to the future: sweatshop conditions on the Mexico-U.S. border. I. Community health impact of maquiladora industrial activity

Present working conditions in one of the most active areas of the maquiladora system along the Mexico-U.S. border are reminiscent of nineteenth-century U.S. sweatshops. This conclusion was reached after evaluating two separate but interrelated surveys among Mexican nationals living near the Mexico-U.S. border, one of community leaders (Paper I), and one of workers in maquiladora enterprises in the towns of Matamoros and Reynosa, Mexico (Paper II). Paper I evaluates the results of the community leaders' survey. Criteria for selection of the leaders were: level of responsibility in the community; knowledge of the industry in the region, and length of residence in the area (more than 3 years). Representatives from government, maquiladora industry management, labor union leadership, labor union activists, and community improvement activists were interviewed. Structured questionnaires with opportunities for open-ended answers were used by trained Spanish speaking interviewers. The questions covered community demographics, health care structures, governance of the region, knowledge of working conditions, and knowledge of environmental impact on the region and the community. Community leaders were ambivalent on the purported benefits of the development of these types of industries in their communities. A substantial majority (21 of 25) thought that the maquiladoras brought few positive developments, other than creating jobs. Serious concerns about overextending weak social infrastructures and about environmental deterioration were voiced. Immediate (preventive) measures appear necessary to develop community infrastructures and to protect environmental health.

A comparison of PMRs and SMRs as estimators of occupational mortality

Standardized mortality ratios (SMRs) for occupational diseases are confounded by health differences between industrial and general populations. In 109 industrial cohorts largely free of work-related mortality, these selection effects were sizable for both malignant and nonmalignant outcomes. All-cancer SMRs were considerably less than 1.0 for many cohorts, and lung cancer was subject to almost as much selection-derived confounding as nonmalignant disease. Standardized proportional mortality ratios (PMRs) (approximated by relative SMRs (RSMRs] were less confounded than SMRs in estimating occupational risk. PMRs appeared to overestimate cancer mortality on average by 6%, while SMRs underestimated by 13%. PMRs underestimated nonmalignant respiratory disease by 16 percent but SMRs underestimated by 39 percent. The sources of confounding, in addition to selection on health status at hire, most likely include social class. SMRs, in the absence of internal population comparisons, would fail to detect both malignant and nonmalignant work-related mortality in many industrial cohorts.

Cancer mortality patterns by work category in three Texas oil refineries

A previous proportionate mortality ratio analysis revealed elevated mortality from brain tumors, stomach cancer, leukemia, and other cancers among OCAW members employed in three Texas oil refineries. In order to evaluate these findings, complete work histories of cases and a matched set of controls who died from other causes of death were obtained from company personnel records. Work histories were summarized by classifying each job title and department entry into one of several broad work categories of refinery unit operations. A worker was considered "exposed" to a work category if he was known to have worked at least 1 day in the category 15 or more years prior to his death. Maximum likelihood estimates of the relative risk for brain tumor, stomach cancer, and leukemia were calculated by work category using a procedure for matched case-control data. No strong associations for brain tumor risk were seen with any work categories. A slight association for leukemia was seen among workers in the Treating category, which included unit operations that reduce the level of aromatic and sulfur constituents of petroleum products and combine them with additives to improve their quality. Stomach cancer risk was elevated among maintenance workers and workers exposed to lubricating oils and paraffin wax processing.

Mortality patterns among workers in three Texas oil refineries

The cause-specific mortality experience of 2,509 active and retired members of the Oil, Chemical, and Atomic Workers International Union (OCAW) who worked at three oil refineries in the Beaumont/Port Arthur area of Texas was examined to determine whether there might be unusual patterns of fatal disease related to workplace exposures. Deaths that occurred between 1943 and 1979 were identified from membership records of the OCAW headquarters in Denver and from the records of union locals in Texas which represent workers at the three refineries. Death certificates were obtained from state vital records offices for the decedents. Cause-specific Proportionate Mortality Ratios (PMRs) were calculated using the mortality experience of the U.S. general population as a standard. Excess mortality from stomach cancer occurred among active union members who worked at Refinery A and among active and retired members who worked at Refineries B and C. PMRs for leukemia, multiple myeloma, and other lymphomas were elevated, especially among retired workers. Relative frequencies of brain tumor deaths were significantly elevated among active members at all three refineries and slightly elevated among retirees at Refineries A and C. Findings suggest that oil refinery workers may have elevated risks of these cancers and indicate that more definitive studies are necessary.

Mortality among workers employed in petroleum refining and petrochemical plants

The cause-specific mortality experience of 3,105 members of the Oil, Chemical and Atomic Workers International Union was examined to determine if there were unusual patterns of fatal disease that may be indicative of hazardous agents in the work environment. Deaths among active Union members that were reported by locals in Texas between 1947 and 1977 were identified through membership records, and proportionate mortality was analyzed in several broad industrial categories. PMRs for cancers of the liver and biliary passages, pancreas, lung and skin were elevated among refinery and petrochemical plant workers; however, risks did not increase with length of membership. Increased relative frequencies of stomach cancer, cancer of the brain, leukemia and multiple myeloma were confined to white males in the same category who had been Union members for 10 or more years. Excess deaths from stomach cancer and brain cancer were found among white male members employed at one specific oil refinery and petrochemical plant. Observed numbers of deaths from cancer of the stomach were greater than expected among whites and nonwhites, and an elevated PMR for lung cancer among nonwhites was found at an additional plant. Findings suggest that workers in this industry may be at increased risk of certain cancers and indicate areas for further investigation.

Biochemical abnormalities in workers exposed to molybdenum dust

Exposure to molybdenum in dust was measured in a molybdenite roasting plant. This exposure was accompanied by large elevations of serum ceruloplasmin and smaller increases in mean serum uric acid levels in the workers. Absorption of molybdenum from the dust was demonstrated by increases in plasma and urinary molybdenum levels. It remains necessary to demonstrate whether such exposure results in long-term health effects.