Germania A. Pinheiro

Rapidly progressive coal workers' pneumoconiosis in the United States: geographic clustering and other factors

Background: Despite significant progress made in reducing dust exposures in underground coal miners in the United States, severe cases of coal workers’ pneumoconiosis (CWP), including progressive massive fibrosis (PMF), continue to occur among coal miners. Aims: To identify US miners with rapidly progressive CWP and to describe their geographic distribution and associated risk factors. Methods: Radiographic evidence of disease progression was evaluated for underground coal miners examined through US federal chest radiograph surveillance programmes from 1996 to 2002. A case of rapidly progressive CWP was defined as the development of PMF and/or an increase in small opacity profusion greater than one subcategory over five years. County based prevalences were derived for both CWP and rapidly progressive cases. Results: A total of 886 cases of CWP were identified among 29 521 miners examined from 1996 to 2002. Among the subset of 783 miners with CWP for whom progression could be evaluated, 277 (35.4%) were cases of rapidly progressive CWP, including 41 with PMF. Miners with rapidly progressive CWP were younger than miners without rapid progression, were more likely to have worked in smaller mines (<50 employees), and also reported longer mean tenure in jobs involving work at the face of the mine (in contrast to other underground mining jobs), but did not differ with respect to mean underground tenure. There was a clear tendency for the proportion of cases of rapidly progressive CWP to be higher in eastern Kentucky, and western Virginia. Conclusions: Cases of rapidly progressive CWP can be regarded as sentinel health events, indicating inadequate prevention measures in specific regions. Such events should prompt investigations to identify causal factors and initiate appropriate additional measures to prevent further disease.

Mesothelioma incidence in 50 states and the District of Columbia, United States, 2003–2008

Abstract Background: The decline in asbestos use in the United States may impact mesothelioma incidence. Objective: This report provides national and state-specific estimates of mesothelioma incidence in the United States using cancer surveillance data for the entire US population. Methods: Data from the National Program for Cancer Registries and the Surveillance, Epidemiology, and End Results program were used to calculate incidence rates and annual percent change. Results: During 2003–2008, an average of 1·05 mesothelioma cases per 100 000 persons were diagnosed annually in the United States; the number of cases diagnosed each year remained level, whereas rates decreased among men and were stable among women. Conclusion: US population-based cancer registry data can be used to determine the burden of mesothelioma and track its decline. Even 30 years after peak asbestos use in the United States, 3200 mesothelioma cases are diagnosed annually, showing that the US population is still at risk.

High-resolution CT in silicosis: correlation with radiographic findings and functional impairment.

Objective: To assess high-resolution computed tomography (HRCT) findings in silicosis and to better define the role of HRCT in early detection of parenchymal abnormalities in silica-exposed workers. Methods: Forty-one stone carvers were evaluated with chest radiographs (CR), HRCT, and pulmonary function tests (PFT). Inter-reader agreement was calculated using the kappa statistic (k). Correlation between radiographic and HRCT profusion scores and PFT was assessed using the Spearman correlation coefficient. Results: The most common HRCT findings were branching centrilobular structures, seen in 28/41 workers (68.3%). Nodules consistent with silicosis were detected in 53.7% workers on CR and in 56.1% workers on HRCT. Inter-reader agreement for diagnosis of silicosis was better on HRCT (k = 0.84) than on CR (k = 0.54). Small opacity profusion on HRCT correlated inversely with total lung capacity and FVC%. Conclusion: Profusion of opacities on HRCT correlates with functional impairment. The presence of branching centrilobular structures may be helpful in early recognition of silicosis.

Occupational Risks for Idiopathic Pulmonary Fibrosis Mortality in the United States

Abstract Metal and wood dust exposures have been identified as possible occupational risk factors for idiopathic pulmonary fibrosis (IPF). We analyzed mortality data using ICD-10 code J84.1-“Other interstitial pulmonary diseases with fibrosis,” derived age-adjusted mortality rates for 1999-2003, and assessed occupational risks for 1999, by calculating proportionate mortality ratios (PMRs) and mortality odds ratios (MORs) using a matched case-control approach. We identified 84,010 IPF deaths, with an age-adjusted mortality rate of 75.7 deaths/ million. Mortality rates were highest among males, whites, and those aged 85 and older. Three industry categories with potential occupational exposures recognized as risk factors for IPF were identified: “Wood buildings and mobile homes” (PMR = 4.5,95% confidence interval (CI) 1.2-11.6 and MOR = 5.3, 95% CI 1.2–23.8), “Metal mining” (PMR = 2.4, 95% CI 1.3–4.0 and MOR = 2.2, 95% CI 1.1–4.4), and “Fabricated structural metal products” (PMR = 1.9,95% CI 1.1–3.1 and MOR = 1.7, 95% CI 1.0–3.1). Workers in these industry categories may benefit from toxicological studies and improved surveillance for this disease.

Asbestosis mortality in the USA: facts and predictions

Background: Mortality trends in the USA show that deaths from asbestosis are increasing, while deaths related to other pneumoconiosis are declining. Objectives: To analyse the association between asbestos consumption and asbestosis mortality trends. Methods: In an epidemiological time series study, we used a modern computer-intensive local regression method to evaluate the relationship between asbestos consumption per capita (1900–2006) as the predictor variable and number of deaths from asbestosis (1968–2004). The predictor variable was progressively lagged by annual increments from 30 to 60 years and the goodness of fit assessed for each lag period. The model having the smallest Akaike’s Information Criteria was used to derive extrapolated estimates of future mortality based on more recent asbestos consumption data. Results: Asbestos consumption per capita reached a peak in 1951 and gradually declined until 1973, when it started to drop rapidly. In 2006, it was 0.0075 kg/person/year. There were 25 564 deaths from asbestosis over the period 1968–2004. The best-fitting model (adjusted coefficient of determination (R2) = 99.7%) for 1968–2004 deaths from asbestosis used asbestos consumption per capita 48 years prior (1920–1956) and the log value of asbestos consumption per capita 43 years prior (1925–1961). This model predicts a total of 29 667 deaths (95% CI 19 629 to 39 705) to occur during 2005–2027 (an average of 1290 deaths per year). Conclusions: This study demonstrates a clear association between asbestos consumption and deaths from asbestosis and indicates that asbestosis deaths are not expected to decrease sharply in the next 10–15 years.

Malignant Mesothelioma Mortality in the United States, 1999–2001

Abstract Malignant mesothelioma is strongly associated with asbestos exposure. This paper describes demographic, geographic, and occupational distributions of mesothelioma mortality in the United States, 1999–2001. The data (n = 7,524) were obtained from the National Center for Health Statistics multiple-cause-of-death records. Mortality rates (per million per year) were age adjusted to the 2000 U.S., standard population, and proportionate mortality ratios (PMRs) were calculated by occupation and industry, and adjusted for age-sex, and race. The overall age-adjusted mortality rate was 11.52, with males (22.34) showing a six fold higher rate than females (3.94). Gographic distribution of mesothelioma mortality is predominantly coastal. Occupations with significantly elevated PMRs included plumbers/pipefitters and mechanical engineers. Industries with significantly elevated PMRs included ship and boat building and repairing, and industrial and miscellaneous chemicals. These surveillance findings, can be useful in generating hypotheses and developin strategies to prevent mesothelioma.

Malignant Mesothelioma Surveillance: A Comparison of ICD 10 Mortality Data with SEER Incidence Data in Nine Areas of the United States

Abstract With the implementation in 1999 of ICD-10 death certificate coding in the United States, mortality data specific to malignant mesothelioma became readily available on a national basis. To evaluate the accuracy and completeness of diagnosis and coding for mesothelioma on the death certificate, mortality information was compared with incidence data. A mortality /incidence ratio was calculated for each of the nine areas covered by the SEER Program, using National Vital Statistics mortality data from 1999 and 2000, and the SEER incidence data for 1998 and 1999. The mortality /incidence ratio for the two years combined for all areas was 0.82. Only two areas (Connecticut and Atlanta) had ratios <80%. The overall correlation coefficient between mortality and incidence rates was 0.96. Thus, mortality data coded using ICD-10 can be a valid source for mesothelioma surveillance and can be instituted without major cost if a national mortality statistics program based on ICD-10 is in place, making it feasible even for developing countries.

Broncholithiasis and lithoptysis associated with silicosis

A case of broncholithiasis associated with massive silicosis is reported, showing a rare aspect of parenchymal lesions generating broncholiths as well as the presence of recurrent lithoptysis, with subsequent regression of radiological lesions. Aetiological, clinical, physiopathological, and radiological aspects of the disease are discussed, demonstrating the importance of the use of computed tomography in diagnosis. The mineralogical analysis of expectorated fragments is also shown.

Mortality from Pleural Mesothelioma in Rio de Janeiro, Brazil, 1979–2000: Estimation from Death Certificates, Hospital Records, and Histopathologic Assessments

Abstract To obtain information about the occurrence of pleural mesothelioma on a population basis in Brazil, mortality related to pleural tumors in the State of Rio de Janeiro during 1979-2000 was examined. Death certificates with pleural tumors as the main cause of death and hospital records were analyzed, together with histopathologic material, which was reevaluated. Of 217 death certificates coded as pleural tumors, 34.1% were considered wrongly coded. Results after reclassification were: definite mesothelioma = 45 cases; probable = 7; possible = 31; inconclusive = 65; other tumors = 11. Thus, the number of mesotheliomas in Rio de Janeiro in 1979-2000 is estimated to have been 83. The analysis also suggests a problem with mortality codification in the State.

Comparison of Digital with Film Radiographs for the Classification of Pneumoconiotic Pleural Abnormalities

RATIONALE AND OBJECTIVES Analog film radiographs are typically used to classify pneumoconiosis to allow comparison with standard film radiographs. The aim of this study was to determine if digital radiography is comparable to film for the purpose of classifying pneumoconiotic pleural abnormalities. MATERIALS AND METHODS Subjects were 200 asbestos-exposed patients, from whom digital and film chest radiographs were obtained along with chest high-resolution computed tomographic scans. Using a crossover design, radiographs were independently read on two occasions by seven readers, using conventional International Labour Organization standards for film and digitized standards for digital. High-resolution computed tomographic scans were read independently by three readers. Areas under the receiver-operating characteristic curves were calculated using high-resolution computed tomographic ratings as the gold standard for disease status. Mixed linear models were fit to estimate the effects of order of presentation, occasion, and modality, treating the seven readers as a random effect. Comparing digital and film radiography for each reader and occasion, crude agreement and agreement beyond chance (κ) were also calculated. RESULTS The linear models showed no statistically significant sequence effect for order of presentation (P = .73) or occasion (P = .28). Most important, the difference between modalities was not statistically significant (digital vs film, P = .54). The mean area under the curve for film was 0.736 and increased slightly to 0.741 for digital. Mean crude agreement for the presence of pleural abnormalities consistent with pneumoconiosis across all readers and occasions was 78.3%, while the mean κ value was 0.49. CONCLUSIONS These results indicate that digital radiography is not statistically different from analog film for the purpose of classifying pneumoconiotic pleural abnormalities, when appropriate standards are used.