Sarcoidosis in Northern Ontario hard-rock miners: A case series.

Sarcoidosis is a rare multisystem granulomatous disease traditionally considered to be of unknown etiology. The notion that sarcoidosis has no known cause is called into question with the increasing number of case reports and epidemiologic studies showing associations between occupational exposures and disease published in the past 10-20 years. Occupational exposures for which associations are strongest and most consistent are silica and other inorganic dusts, World Trade Center (WTC) dust, and metals. Occupations identified as at-risk for sarcoidosis include construction workers; iron-foundry and diatomaceous earth workers; WTC emergency responders; and metal workers. We report here 12 cases of sarcoidosis in a cohort of hard-rock miners in Northern Ontario, Canada. To our knowledge sarcoidosis has not been reported previously in hard-rock miners. The cases are all male and Caucasian, with average age 74 years. At the time of diagnosis, two were never smokers; six, former smokers; and four, current smokers. Five have extrapulmonary sarcoidosis: two cardiac and three endocrine (hypercalciuria). Using occupational histories and air sampling data from the gold, uranium, and base-metal mines in which they worked, we examined exposure of each case to respirable crystalline silica (RCS). The annual mean RCS exposure for the 12 cases was 0.14 mg/m3 (range: 0.06-1.3 mg/m3 ); and the mean cumulative RCS exposure was 1.93 mg/m3  years (range: 0.64-4.03 mg/m3  years). We also considered their exposure to McIntyre Powder, an aluminum powder used for silicosis prophylaxis.

Malignant mesothelioma: Ongoing controversies about its etiology in females.

Malignant mesothelioma (MM) is one of the most aggressive cancers with the poorest of outcomes. There is no doubt that mesothelioma in males is related to asbestos exposure, but some authors suggest that most of the cases diagnosed in females are "idiopathic." In our assessment of the science, the "low risk" of mesothelioma in females is because of the nonsystematic recording of exposure histories among females. Indeed, asbestos exposure is mentioned in only some of the studies that include females. We estimate the risk of MM among females to be close to that in males. The absence of detailed exposure histories should be rectified in future studies involving ​women. As a matter of social justice, the ongoing failure to recognize asbestos as the cause of a majority of cases of MM in females does them, and their kin, a profound disservice.

Myositis associated with carbon monoxide poisoning.

Introduction: Carbon monoxide (CO) poisoning causes hypoxia and inflammation, which could adversely affect muscle. We could find no published information about CO poisoning causing myositis. Case report: A 53-year-old previously healthy female semi truck driver had CO poisoning from a faulty diesel engine exhaust intermittently over three months, culminating in an episode of acute CO poisoning, with syncope after exiting the truck at the end of the three-month period. Neuropsychological symptoms immediately after the acute poisoning event were followed by the development of fatigue, weakness and myalgias within two months and a diagnosis of "polymyositis" within four months. C-reactive protein and creatine kinase were elevated. Electromyogram showed pure myopathy without sensory abnormalities. Occult malignancy was ruled out. Thigh muscle biopsy revealed severe inflammatory myopathy and myonecrosis. Muscle specialist pathologists interpreted the biopsy as toxic or viral inflammatory myopathy, not polymyositis, with CO poisoning as the likely etiology. She received steroids and mycophenolate. Nineteen months later, a repeat biopsy was negative for inflammation or myopathic process. Alternative diagnoses were ruled out by clinical investigation and her course over the next five years. Conclusion: This patient's presentation and clinical course support a diagnosis of myositis from CO poisoning, although it is possible that the myositis was either idiopathic or post-viral (without evidence of a causative virus).

Amyotrophic lateral sclerosis-A case report and mechanistic review of the association with toluene and other volatile organic compounds.

Unmasking of latent neurodegenerative disease has been reported following exposure to chemicals that share one or more mechanisms of action in common with those implicated in the specific disease. For example, unmasking of latent Parkinson's disease (PD) has been associated with exposure to anti-dopaminergic agents, while the progression of pre-existing mild cognitive impairment and unmasking of latent Alzheimer's disease has been associated with exposure to general anesthetic agents which promote Aß protein aggregation. This literature review and clinical case report about a 45-year-old man with no family history of motor neuron disease who developed overt symptoms of a neuromuscular disorder in close temporal association with his unwitting occupational exposure to volatile organic compounds (VOCs) puts forth the hypothesis that exposure to VOCs such as toluene, which disrupt motor function and increase oxidative stress, can unmask latent ALS type neuromuscular disorder in susceptible individuals.

Sarcoidosis: An Occupational Disease?

Sarcoidosis is an important member of the family of granulomatous lung diseases. Since its recognition in the late 19th century, sarcoidosis has been thought of as a disease of unknown cause. Over the past 20 years, this paradigm has been shifting, more rapidly in the past 10 years. Epidemiologic studies, bolstered by case reports, have provided evidence of causal associations between occupational exposure to specific agents and sarcoidosis. Pathogenesis has been more clearly defined, including the role of gene-exposure interactions. The use of in vitro lymphocyte proliferation testing to detect sensitization to inorganic antigens is being examined in patients with sarcoidosis. These antigens include silica and certain metals. Results of studies to date show differences in immunoreactivity of occupationally exposed sarcoidosis cases compared with control cases, suggesting that lymphocyte proliferation testing may prove useful in diagnosing work-related disease. This review discusses recently published findings regarding associations between occupational exposure to silica and silicates, World Trade Center dust, and metals and risk for sarcoidosis, as well as advances in the development of diagnostic tools. Not all cases of sarcoidosis have an identified cause, but some do. Where the cause is occupational, its recognition is critical to enable effective treatment through removal of the affected worker from exposure and to inform intervention aimed at primary prevention.

Protecting our children's health: The ultimate government 'stimulus package'.

The Children's Environment and Health Action Plan for Europe has established four Regional Priority Goals (RPG) for the protection of the health of children. Hutter et al (JPHP 2009) have developed and tested an accessible method for addressing one aspect of RPG III: indoor and outdoor air pollution. The study provides an accessible method for use by communities to access effects of air pollution in and around the home on the respiratory health of children. This Commentary reviews that study, as well as other evidence in the scientific literature of effects of indoor and outdoor air pollution on children's respiratory health. In addition, this Commentary discusses the importance of air quality in schools to children's respiratory health and to school attendance and performance, citing supportive dat and urging action on this front.

Dual-energy digital subtraction chest radiography: technical considerations.

In the evaluation of asbestos-related pulmonary and pleural abnormalities, conventional chest radiography has been shown to have a low sensitivity for the detection of lung nodules and subtle interstitial disease. Pleural plaques may simulate pulmonary nodules, and interstitial processes can be masked by adjacent pleural abnormalities. Dual-energy digital subtraction chest radiography may enable investigators to characterize asbestos-related pulmonary and pleural abnormalities with greater accuracy. "Soft-tissue" images, designed to remove pleural calcifications, may allow for better evaluation of the lung parenchyma. "Bone" images, designed to remove soft-tissue structures, may enhance the detection of pleural calcifications. In this pictorial essay we illustrate the methods, technical considerations, and limitations of dual-energy digital subtraction chest radiography performed with global subtraction weighting factors.

Workplace exacerbation of asthma symptoms: findings from a population-based study in Maine.

In this population-based study of asthma in the State of Maine, the authors investigated how often asthma symptoms were exacerbated in the workplace. Participants from 5 hospital service areas in Maine completed a telephone questionnaire. Of 474 adult participants (18-65 yr of age) employed during the preceding year and for whom information on occupation and industry was available, 64 (13.5%) were identified with current asthma, including 28 (5.9%) with current physician-diagnosed asthma and 36 (7.6%) who met criteria for symptoms consistent with asthma. Jobs were identified a priori as "high-risk" or "low-risk" for asthma. Of the 64 asthma cases, 16 (25%) reported that their coughing or wheezing worsened at work. Among the symptom-based cases, the percentage with workplace exacerbation of asthma was elevated for high-risk jobs (7/14 = 50%) vs. low-risk jobs (3/22 = 13.6%) (p = 0.03). No similar elevation was observed for individuals with current physician-diagnosed asthma, which might have resulted, in part, from a healthy worker effect.

Airway disease in highway and tunnel construction workers exposed to silica.

BACKGROUND: Construction workers employed in a unique type of tunnel construction known as tunnel jacking were exposed over an 18-month period to respirable crystalline silica at concentrations that exceeded the OSHA permissible exposure limit. The present study examines workplace exposures and occurrence of airway disease in these workers. METHODS: Medical and occupational histories and chest radiographs were obtained on 343 active construction workers who had worked on the site during the period in question. Chest radiographs were interpreted according to the ILO-1980 system of classification. Standardized questions were used to develop an algorithm to define symptoms consistent with asthma (SCA) and to determine these respiratory outcomes: chronic bronchitis, shortness of breath (SOB), and physician-diagnosed asthma (current vs. not current). Relationships with each of three work activities were examined: slurry wall breakthrough (SWB), chipping caisson overpour, and tunneling/mining. RESULTS: Participants included laborers, carpenters, tunnel workers, ironworkers, operating engineers, and electricians. No cases of silicosis were found on chest X-ray. Overall prevalence of chronic bronchitis, SCA, SOB, and physician-diagnosed asthma was 10.7%, 25%, 29%, and 6.6%, respectively. Odds ratios (OR) for carpenters compared to laborers were significantly elevated for chronic bronchitis, SCA, and SOB. SWB was associated with chronic bronchitis and SCA (OR 4.93, 95% CI = 1.01, 24.17; OR 3.32, 95% CI = 1.25, 8.84, respectively). The interaction between SWB, SCA, and trade was significant for carpenters (OR 6.87, 95% CI = 1.66, 28.39). Inverse trends were observed for months on the site and chronic bronchitis, SCA, and SOB (P = 0.0374, 0.0006, and 0.0307, respectively). CONCLUSIONS: Tunnel construction workers exposed to respirable crystalline silica and cement dust are at increased risk for airway disease. Extent of risk varies by trade and work activity. Our data indicate the importance of bystander exposures and suggest that tunnel jacking may be associated with greater risk compared to more traditional methods of tunnel construction. A healthy worker effect is suggested.

Development of a prototype system for statewide asthma surveillance.

OBJECTIVES: We developed and evaluated a statewide and community-level asthma surveillance system. METHODS: Databases and measures included a community prevalence survey, hospital admissions data, emergency department/outpatient clinic visit records, and a physician survey of diagnosis and treatment practices. We evaluated the system in 5 Maine communities varying in population and income. RESULTS: Asthma hospitalizations were high in the rural/low-socioeconomic-status communities studied, although diagnosed asthma was low. Males were more likely than females to experience asthma symptoms, although they were less likely to have been diagnosed with asthma or to have used hospital-based asthma care. CONCLUSIONS: Databases were useful for estimating asthma burden and identifying service needs as well as high-risk groups. They were less useful in estimating severity or in identifying environmental risks.