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From 1943 to 1979, miners and factory workers in more than two hundred work sites globally were subjected to mandatory medical treatments by their employers as an unproven, and ultimately ineffective, treatment to prevent the lung disease silicosis. The treatments involved inhaling finely ground aluminum dust known as McIntyre Powder, blown into miners’ change rooms each shift using compressed air systems. Tens of thousands of industrial laborers were exposed to McIntyre Powder, yet their story is scarcely known, and the possible health impacts of their aluminum treatments were rarely studied. This paper integrates the history of the aluminum prophylaxis program and its control by the northern Ontario mining industry with the lived experience of one of the affected miners, whose daughter created a voluntary registry which documents health issues in exposed miners, and stimulated research that found a link to her father’s Parkinson disease.

Necrophagous flies are of great importance for human and animal health. In places where their development occurs, parasitoids can be used as a tool to control these dipterans. In Brazil, the fauna of these parasitoids has been investigated in some regions. However, in Rio Grande do Sul, it is known the occurrence of only one species. Thus, this study aimed to create the first list of parasitoids in flies of medical and veterinary importance in Southern Brazil. Collections took place in the municipality of Pelotas (31º 42’ S; 52º 18’ W). Three replicates consisting of a 500 g bovine liver chunk placed in a tray were exposed to open air for 20 days. Then pupae were individualized and observed until their emergence. We identified 4,882 adult flies of Calliphoridae, Fanniidae, Muscidae, and Sarcophagidae. 4,040 parasitoids emerged, belonging to eight species, of which Nasonia vitripennis, Spalangia cameroni, Spalangia chontalensis, and Tachinephagus zealandicus are new records in Rio Grande do Sul state. Also, three undescribed species of the genus Aphaereta were collected. In spite of being the first attempt to inventory the fauna of hymenopteran parasitoids, this study may help in the development of management programs of these dipterans in the region. Resumo Moscas necrófagas possuem grande importância para a sanidade humana e animal. Onde estas se desenvolvem ocorrem parasitoides que podem ser utilizados como ferramentas para o controle desses dípteros. No Brasil, a fauna desses parasitoides vem sendo investigada em algumas regiões e no Rio Grande do Sul é conhecida a ocorrência de apenas uma espécie. Portanto, o objetivo deste estudo foi criar a primeira lista de espécies de parasitoides de moscas de importância médica e veterinária ocorrentes no extremo sul do Brasil. As coletas foram realizadas no município de Pelotas (31º 42’ S; 52º 18’ O). Foram montadas três réplicas de bandejas contendo, cada uma, 500 g de fígado bovino, expostas ao ar livre durante 20 dias. Na sequência, as pupas foram individualizadas e observadas até a emergência. Foram identificados 4.882 adultos pertencentes às famílias Calliphoridae, Fanniidae, Muscidae e Sarcophagidae. Emergiram 4.040 parasitoides, pertencentes a oito espécies, das quais Nasonia vitripennis, Spalangia cameroni, Spalangia chontalensis e Tachinephagus zealandicus são novas ocorrências para o Rio Grande do Sul. Foram coletadas três espécies ainda não descritas do gênero Aphaereta. Apesar de ainda ser um primeiro esforço de inventariar a fauna de himenópteros parasitoides, este estudo pode auxiliar no desenvolvimento de programas de manejos desses dípteros na região.

A world focused on the threat of a pandemic has not paid attention to an even greater threat that is upon us – one no longer looming in the far distance but arriving in strength and crashing on top...

The traditional way of teaching environmental health is to concentrate on the hazard: how toxic or dangerous is it, what is the risk, who is most susceptible, who is most vulnerable, where does it ...

Environmental health is where public health began, in the middle of the nineteenth century in Europe. The core model of environmental health, what distinguishes it, has been the “source-exposure-re...

The relationship between scientific freedom and human rights is as deep on the side of science as it is on the side of human rights. On the one hand, issues of the application of science and techno...

The environmental health sciences, including occupational health, are front and center in the current battle for respect of science. Partly because of the policy implications of environmental resea...

Anyone reading this journal or following the world literature knows perfectly well that environmental health is a global concern, because pollution and ecosystem change know no boundaries. However,...

In environmental and occupational health we are accustomed to thinking about target organs for toxic exposures. We are concerned with effects on the lungs, kidney, and liver. We seldom think of the...

A political development in the United States, the Green New Deal,1 unexpectedly opens new possibilities for environmental and occupational health research. Far from being an “unserious” partisan po...

Occupational medicine concerns keeping workers healthy, screening for early signs of health problems, and promoting good health through workplace initiatives. According to recent estimates, 55,000 deaths and 3.8 million disabling injuries per year result from occupational illness at a cost of $125 to $155 billion. This chapter covers the basic principles and clinical evaluation of occupational disease, guidelines for taking a patient’s occupational history, and exposure assessment. Major occupational disorders in developed countries are discussed, including respiratory tract disorders, skin disorders, disorders of the kidneys, liver disease, central and peripheral nervous systems, organs of sensation, occupational cancer, musculoskeletal disorders, hematologic disorders, endocrine and reproductive effects, stress and psychogenic effects, and nonspecific illness. Tables outline critical dimensions of occupational medicine, the conceptual approach to a patient with a suspected workplace injury or illness, common hazards with widely available tests for exposure, historically common occupational disorders, and established occupational carcinogens. Figures includes a chest film of asbestosis, a sample occupational and environmental history questionnaire, lungs in various states of pneumoconiosis, a photograph of contact dermatitis, and a graph showing hearing decline at 4,000 Hz frequency. Illustrations demonstrate the impact of occupational exposure on the kidneys and liver and the anatomy of the hearing mechanism. This review contains 9 highly rendered figures, 5 tables, and 112 references.

On April 22, 2017, over 100,000 scientists, engineers, students, and people concerned for the scientific enterprise marched in mass demonstrations in major cities and more than a few small towns an...

We who have made our careers in environmental and occupational health are proud of the progress we have made in managing difficult problems and understanding complexity and interdependent relations...

Bodur, Said (Balikesir Author), Violence in the workplace is an increasing occupational health concern worldwide. Health care workers are at high risk of assault. To develop, monitor, and manage prevention policies, baseline data should be available. This cross-sectional study was designed to determine the current extent of workplace violence nationwide in Turkey. The study population of 12.944 health care workers was a stratified sample of all health care workers (612,639) in the country. A probabilistic sampling was made on the basis of the “multistage stratified random cluster sampling method.” This study was conducted by a structured questionnaire in a face-to-face interview. The questionnaire items were adapted and translated into Turkish based on questionnaires of International Labor Organization, International Council of Nurses, World Health Organization, and Public Services International. The percentage of health care workers who experienced workplace violence in Turkey in the previous 12 months was 44.7%. The types of violence included physical 6.8%, verbal 43.2%, mobbing (bullying) 2.4%, and sexual harassment 1%. Multivariate analysis showed that level of health care system, type of institution, gender, occupation, age, working hours, and shift work were independent risk factors for experiencing workplace violence (p

When it comes to the city of science, we who work in environmental and occupational health live in a bad neighborhood. We are often at the center of controversial issues and in the crossfire of com...

The Occupational Health Program (OHP) at the University of Alberta played an important and pioneering role in the specialty of occupational medicine in Canada between 1984 and 1999. Its history illustrates the opportunities and obstacles in one of the smallest and most unusual medical specialties in Canada. After an auspicious beginning in 1984, with support from industry, labour, government, and the university, the OHP encountered, but overcame, many problems subsequently as a result of underfunding, organizational placement, and, after changes in leadership, interference from the provincial government department responsible for occupational health. The history of the OHP illustrates problems of small training programs and the unique problems of occupational medicine but also its potential as a model for medical training out of hospital that responds to population health as well as individual care.

Distrust of science is an ascendant trend of our times. No, after years of being an obstacle to environmental improvement and health protection has suddenly become a possibly existential threat by ...

Health threats place the military mission and deployed service members at risk. A commander’s focus is on preventing acute health risks, such as diarrhea, because these quickly compromise the mission. However, in recent conflicts chronic and long-term illness risks have emerged as concerns. Department of Defense and Joint Chiefs of Staff mandates require documentation of exposures and environmental conditions to reconstruct exposures and evaluate future health risks. Current processes for identifying and assessing hazards, including identification and assessment before deployment and in time to take action to prevent or reduce exposures, when followed, are generally adequate for known hazards. Identifying and addressing novel, unexpected risks remain challenges. Armed conflicts are associated with rapidly changing conditions, making ongoing hazard identification and assessment difficult. Therefore, surveillance of the environment for hazards and surveillance of personnel for morbidity must be prac...

Studies of risk communication have identified healthcare providers, especially physicians, as the source of information most trusted by the public on issues of environmental health. Nothing in medical, nursing or most healthcare provider training actually prepares practitioners to play this role and healthcare providers are generally more oriented toward treatment and medical care than prevention and public health. Healthcare providers require education in order to play this role but rarely seek it. Gaps in the knowledge of professional on the issue of Cryptosporidium illustrate the problem. For members of the professional water community, communicating with healthcare providers is best done when messages are delivered in familiar settings, such as hospital Grand Rounds (a universal format for teaching conferences) and provided in a narrative (case-based) form but gaining access is difficult if the topic is not obviously clinical in nature. In addition to being a critically important target group itself, public health professionals are easier to reach and may mediate good working relationships with medical practitioners. We suggest a strategy for water utilities based on partnerships with academic public health and providing education through well-recognized formats in continuing medical and nursing education.

Background The evaluation of causality in cancers associated with firefighting presents problems common to other applications of occupational epidemiology in adjudication of individual claims for workers' compensation. A trend in Canada to establish legislated presumptions for compensation of firefighters created an opportunity to re-evaluate the literature applying medicolegal standards of certainty. Objective To evaluate causality in selected cancer categories for firefighters using the criteria applied in tort litigation and workers' compensation, which is based on the weight of evidence and which is required to take into account individual factors. Methods The epidemiological literature on cancer risk among firefighters was reviewed based on the weight of evidence rather than scientific certainty. Generalizable frameworks were formulated to define recurrent issues in assessing the evidence from epidemiological studies. The evidence for latency and for a threshold effect with duration of employment was also examined in order to provide practical guidelines. Results Presumption is justified for the following cancers: bladder, kidney, testicular and brain, and lung cancer among non-smokers. Non-Hodgkin lymphoma, leukaemia and myeloma (each as a class) not only present particular problems in assessment but also merit an assumption of presumption. Four analytical frameworks describe the problems in analysis encountered. Discussion The preponderance of evidence supports the presumption of causation for certain cancer, mostly rare. These frameworks are applicable to other problems of adjudication that rest on interpretation of epidemiological data. The named cancers, taking into account the special assessment issues described by each framework, are supported by sufficient evidence to conclude that a presumption is warranted but not necessarily sufficient evidence to accept as proof by a scientific standard.

Background In 2003, residents of the District of Columbia (DC) experienced an abrupt rise in lead levels in drinking water, which followed a change in water-disinfection treatment in 2001 and which was attributed to consequent changes in water chemistry and corrosivity. Objectives To evaluate the public health implications of the exceedance, the DC Department of Health expanded the scope of its monitoring programs for blood lead levels in children. Methods From 3 February 2004 to 31 July 2004, 6,834 DC residents were screened to determine their blood lead levels. Results Children from 6 months to 6 years of age constituted 2,342 of those tested; 65 had blood lead levels > 10 μg/dL (the “level of concern” defined by the Centers for Disease Control and Prevention), the highest with a level of 68 μg/dL. Investigation of their homes identified environmental sources of lead exposure other than tap water as the source, when the source was identified. Most of the children with elevated blood lead levels (n = 46; 70.8%) lived in homes without lead drinking-water service lines, which is the principal source of lead in drinking water in older cities. Although residents of houses with lead service lines had higher blood lead levels on average than those in houses that did not, this relationship is confounded. Older houses that retain lead service lines usually have not been rehabilitated and are more likely to be associated with other sources of exposure, particularly lead paint. None of 96 pregnant women tested showed blood lead levels > 10 μg/dL, but two nursing mothers had blood lead levels > 10 μg/dL. Among two data sets of 107 and 71 children for whom paired blood and water lead levels could be obtained, there was no correlation (r2 = –0.03142 for the 107). Conclusions The expanded screening program developed in response to increased lead levels in water uncovered the true dimensions of a continuing problem with sources of lead in homes, specifically lead paint. This study cannot be used to correlate lead in drinking water with blood lead levels directly because it is based on an ecologic rather than individualized exposure assessment; the protocol for measuring lead was based on regulatory requirements rather than estimating individual intake; numerous interventions were introduced to mitigate the effect; exposure from drinking water is confounded with other sources of lead in older houses; and the period of potential exposure was limited and variable.

The American Thoracic Society (ATS), in collaboration with George Mason University, surveyed a random sample of ATS members to assess their perceptions of, clinical experiences with, and preferred policy responses to climate change. An e-mail containing an invitation from the ATS President and a link to an online survey was sent to 5,500 randomly selected U.S. members; up to four reminder e-mails were sent to nonrespondents. Responses were received from members in 49 states and the District of Columbia (n = 915); the response rate was 17%. Geographic distribution of respondents mirrored that of the sample. Survey estimates' confidence intervals were ±3.5% or smaller. Results indicate that a large majority of ATS members have concluded that climate change is happening (89%), that it is driven by human activity (68%), and that it is relevant to patient care ("a great deal"/"a moderate amount") (65%). A majority of respondents indicated they were already observing health impacts of climate change among their patients, most commonly as increases in chronic disease severity from air pollution (77%), allergic symptoms from exposure to plants or mold (58%), and severe weather injuries (57%). A larger majority anticipated seeing these climate-related health impacts in the next 2 decades. Respondents indicated that physicians and physician organizations should play an active role in educating patients, the public, and policy makers on the human health effects of climate change. Overall, ATS members are observing that human health is already adversely affected by climate change and support responses to address this situation.

▪ Abstract Workers' compensation in the past two years has been dominated by events in California, which have been so fundamental as to merit the term big bang. Passage of Senate Bill 899 has led to a comprehensive program of reform in access to medical care, access to rehabilitation services, temporary and permanent disability, evidence-based management, dispute resolution, and system innovation. Two noteworthy developments thus arose: a new requirement for apportionment by cause in causation analysis, and the adoption of evidence-based criteria for impairment assessment, treatment guidelines, and, soon, utilization review. Elsewhere in the United States, changes were modest, but extensive legislative activity in Texas suggests that Texas will be next to make major changes. In Canada, the Workers' Compensation Board of British Columbia has adopted an ambitious strategic initiative, and there is a Canadawide movement to establish presumption for certain diseases in firefighters. Suggestions for future directions include an increased emphasis on prevention, integration of programs, worker participation, enhancing the expertise of health care professionals, evidence-based management, process evaluation, and opportunities for innovation.

Background Although stainless steel has been produced for more than a hundred years, exposure-related mortality data for production workers are limited. Aims To describe cause-specific mortality in Finnish ferrochromium and stainless steel workers. Methods We studied Finnish stainless steel production chain workers employed between 1967 and 2004, from chromite mining to cold rolling of stainless steel, divided into sub-cohorts by production units with specific exposure patterns. We obtained causes of death for the years 1971–2012 from Statistics Finland. We calculated standardized mortality ratios (SMRs) as ratios of observed and expected numbers of deaths based on population mortality rates of the same region. Results Among 8088 workers studied, overall mortality was significantly decreased (SMR 0.77; 95% confidence interval [CI] 0.70–0.84), largely due to low mortality from diseases of the circulatory system (SMR 0.71; 95% CI 0.61–0.81). In chromite mine, stainless steel melting shop and metallurgical laboratory workers, the SMR for circulatory disease was below 0.4 (SMR 0.33; 95% CI 0.07–0.95, SMR 0.22; 95% CI 0.05–0.65 and SMR 0.16; 95% CI 0.00–0.90, respectively). Mortality from accidents (SMR 0.84; 95% CI 0.67–1.04) and suicides (SMR 0.72; 95% CI 0.56–0.91) was also lower than in the reference population. Conclusions Working in the Finnish ferrochromium and stainless steel industry appears not to be associated with increased mortality.

Human health studies emphasize the link between the human body and the immediate influences upon it. Ecosystem health studies (defined by David Rapport et al., this volume) has, as its primary objective, the relationships and system characteristics of viable ecosystems. As a practical application, ecosystem health studies describe the mechanisms and assesses the potential to threaten or enhance human health. Keywords: Air quality, Ecology, Greenhouse effect, Linkages, Public health

Workers' compensation systems attempt to evaluate claims for occupational disease on an individual basis using the best guidelines available to them. This may be difficult when there is more than one risk factor associated with the outcome, such as asbestos and cigarette smoking, and the occupational exposures is not clearly responsible for the disease. Apportionment is an approach that involves an assessment of the relative contribution of work-related exposures to the risk of the disease or to the final impairment that arises for the disease. This article discusses the concept of apportionment and applies it to asbestos-associated disease. Lung cancer is not subject to a simple tradeoff between asbestos exposure and smoking because of the powerful biological interaction between the two exposures. Among nonsmokers, lung cancer is sufficiently rare that an association with asbestos can be assumed if exposure has occurred. Available data suggest that asbestos exposure almost invariably contributes to risk among smokers to the extent that a relationship to work can be presumed. Thus, comparisons of magnitude of risk between smokers and nonsmokers are irrelevant for this purpose. Indicators of sufficient exposure to cause lung cancer are useful for purposes of establishing eligibility and screening claims. These may include a chest film classified by the ILO system as 1/0 or greater (although 0/1 does not rule out an association) or a history of exposure roughly equal to or greater than 40 fibres/cm3 x y. (In Germany, 25 fibres/cm3 x y is used.) The mere presence of pleural plaques is not sufficient. Mesothelioma is almost always associated with asbestos exposure and the association should be considered presumed until proven otherwise in the individual case. These are situations in which only risk of a disease is apportioned because the impairment would be the same given the disease whatever the cause. Asbestosis, if the diagnosis is correct, is by definition an occupational disease unless there is some source of massive environmental exposure; it is always presumed to be work-related unless proven otherwise. Chronic obstructive airways disease (COAD) accompanies asbestosis but may also occur in the context of minimal parenchymal fibrosis and may contribute to accelerated loss of pulmonary function. In some patients, particularly those with smoking-induced emphysema, this may contribute significantly to functional impairment. An exposure history of 10 fibre x years is suggested as the minimum associated with a demonstrable effect on impairment, given available data. Equity issues associated with apportionment include the different criteria that must be applied to different disorders for apportionment to work, the management of future risk (eg. risk of lung cancer for those who have asbestosis), and the narrow range in which apportionment is really useful in asbestos-associated disorders. Apportionment, attractive as it may be as an approach to the adjudication of asbestos-related disease, is difficult to apply in practice. Even so, these models may serve as a general guide to the assessment of asbestos-related disease outcomes for purposes of compensation.

Acute exposure to hydrogen sulfide (H2S) causes 4 dose-dependent responses: hyperpnea, unconsciousness or knockdown, apnea, and death. At present, scientific mechanisms for these effects are unknown, but inhibition of cytochrome oxidase in the central nervous system (CNS) by sulfide has been suggested. In this study, the premise of brain as target is examined by comparing peripheral with direct delivery of sulfide to brain. NaHS was administered to anesthetized Sprague-Dawley male rats, by femoral intravenous, or carotid intra-arterial injection. With apnea as the test, ED100 values of 0.6 and 3.0 mg kg(-1) were found for peripheral and direct delivery to brain, respectively. Peripheral delivery is 5 times as effective as direct delivery to the brain, and greater if the relative dilution factors are considered. Lidocaine, applied to the vagus, prevented apnea, so lung-brain transmission was essential. It was therefore concluded that the lung is the peripheral site of action. Hyperpnea increased in duration with dose. The carotid body, located distal to the arterial catheter, sensed the high doses of NaHS but did not trigger apnea. Intravenous infusion or intraperitoneal injection with NaHCO3 prevented hyperpnea, apnea, and death. The following conclusions are drawn: the carotid body is not implicated in NaHS-induced apnea, the lung and not brain harbors the primary site of action of H2S, and an afferent neural signal from the lung via the vagus induces the apnea. Finally, NaHCO3 appears to prevent toxicity from sulfide, and therefore H2S, by some unexplained mechanism. Practical emergency treatment for acute toxicity in the field may be possible.

The effects of exposure to carbon disulphide have been studied mostly among workers in the viscous rayon industry, where the usual exposure profile has been relatively steady exposure over work shifts. We investigated 13 workers in a small chemical company who were exposed to low levels, peaking intermittently to relatively high levels in the range of 100-200 ppm at the end of the work shift, a pattern that may change the risk profile. Our investigation was part of a compliance order that was fought by the company and our access and follow-up was limited. Two workers had burns on their bodies associated with exposure to caustic. Four had elevations in total serum cholesterol, one had elevated serum triglycerides and three had elevations in fasting blood glucose - two of them were known to be diabetics before employment and one had a history of unexplained peripheral neuropathy. No consistent pattern suggestive of a defined lipoprotein abnormality was obvious but several atherogenic profiles were observed. Five had abnormalities on electrocardiogram, four of whom appeared to be among the most heavily exposed. The presence of these changes taken together in this context may suggest accelerated atherosclerotic changes. Tests of liver and kidney function were within the normal range for all workers, as was a complete blood count. Four of the workers had evidence of a bilateral reduction in hearing threshold at 4,000 Hz. A complete set of recommendations was forwarded to the employer, emphasizing further control of exposure to carbon disulphide, personal protection requirements and a cardiovascular risk reduction programme. Conditions improved in the plant following modifications introduced in response to a stop work order from the provincial government's occupational health and safety agency. However, a fire in 1998 put the company out of business and ended further follow-up or interventions. We conclude that these findings, while difficult to interpret because of the circumstances of the investigation, are compatible with an atherogenic effect of exposure to peaking levels of carbon disulphide. The observation should be tested in a larger population with fewer confounding factors and greater control over the investigation.

Physicians and public health professionals working with the U.S. Environmental Protection Agency’s Region 8 Pediatric Environmental Health Specialty Unit (PEHSU) received several telephone calls requesting information regarding the safety of recycled tire crumb as a playground surface constituent placed below children’s play structures. There were no reported symptoms or adverse health effects in exposed children. The literature available on the safety and risk of exposure to crumb rubber constituents was limited and revealed no information quantifying exposures associated with product use. Callers were informed by the PEHSU that no evidence existed suggesting harm from intended use of the product, but gaps in knowledge about the product were identified and communicated. Here the case of crumb rubber on playgrounds is used as a model to present an approach to similar environmental medicine questions. From defining the question, to surveying traditional and nontraditional resources for information, synthesis of findings, and risk communication, the case provides a model to approach similar questions.

Trace element profile analysis detects and quantifies the presence of several metals simultaneously at low concentrations in the body. In occupational medicine, it may be used to monitor exposure or to evaluate suspected toxicity. Clinical interpretation is often difficult because, with the exception of lead and possibly cadmium, there is little firm information on toxicity thresholds. For these tests, the reference ranges typically reflect low levels of exposure in the general population and it is expected that workers handling metals in occupations such as welding and industries such as steelmaking will have higher levels. Interpretation requires some knowledge of the toxicokinetics of the metal of interest and the preferred medium for analysis for each: serum, whole blood or urine (preferably 24-hour collection). Trends are often more informative than concentrations at one time. Trace element values are reported together with a reference range which must be distinguished from the normal range of other clinical tests. As a practical matter, the greatest interpretation problems tend to be found with manganese because serum levels have a poor correlation with both recent exposure and neurological symptoms. Molybdenum and vanadium are often found to be elevated among workers exposed to metals who show no evidence of clinical illness. Interpretation of the trace element profile analysis overall when an elevation occurs generally requires close attention to the pattern of elevation, clinical context, absolute and relative magnitude of the elevation and knowledge of the exposure history.

Occupational medicine in Canada presents many paradoxes and anomalies. This paper outlines the history, status, and current direction of occupational medicine in the country, with an emphasis on the unusual features of the Canadian experience.

Background Workplace violence has become an issue of increasing concern of in public health, in Turkey elsewhere. Healthcare workers are at particular risk of workplace violence. In order to develop prevention policies for workplace violence, the current and objective data should be available. This study aims to provide such data, obtained with a stratified sample representative of the country and a whole. Methods A cross-sectional study was conducted from …

This second of two parts continues with the development of a framework for understanding air quality issues and their relationship to human health. Recognized health effects associated with air pollution are described and current controversies regarding ozone and PM10are briefly outlined. Epidemiological methods of investigating air quality effects are discussed, comparing recent landmark studies in Canada. Comparative prevalence studies do not reflect the state of the art in air pollution epidemiology but are frequently cited and conducted in Canada as if they were definitive. The implications of setting air quality standards and objectives on this basis or to meet arbitrary levels of risk of health effects are examined. The current state of the art does not support risk-based air quality standards. A policy of continuous improvement is most protective of both human health and the environment.

Trends in mortality from chronic obstructive pulmonary disease (COPD) in Alberta over 60 years, from 1927 to 1987, for ages 15 and above or both sexes, were examined. There was a striking decline in mortality among older adults in the 1930s and 1940s. a nadir that lasted almost 10 years in the 1950s, and a striking increase thereafter. By 1970, most age groups had returned to levels of the 1930s. This overall trend was observed in both the younger age groups (aged 15 to 50) and older adults, although mortality from COPD in the former disproportionately reflected asthma-related deaths. Subsequently, mortality climbed still higher in older age groups, but not in the younger age groups. The sustained rise in mortality in older age groups after the Second World War is presumably related to smoking habits. Historical trends in Alberta were then compared with Canada as a whole for both sexes over 50 years of age. Although Alberta had a much lower mortality from COPD than Canada as a whole, this difference disappeared by 1980. There is no obvious explanation that would explain all of the observed trends, but they appear more likely to be a consequence of social and environmental conditions, including changes in health-related behaviour, than of major changes in medical management at the time.