Respiratory impairment in Brazilian foundry workers exposed to sand.

OBJECTIVE: Foundries date back to the 16th century in Brazil and still constitute a strong economic activity today. Workers are at risk of respiratory diseases due to various exposures such as polycyclic aromatic hydrocarbons, pyrolysis degradation products, mineral dust, organic dust, resin, and isocyanates. We evaluate respiratory morbidity among workers in foundries using sand. METHODS: Six foundries with sand molding operations were selected. Length of exposure in years was utilized as a surrogate for exposure. The medical evaluation consisted of a respiratory symptoms questionnaire, occupational history, spirometry, and chest X-rays. Additionally, workers exposed to resins and a control group underwent bronchial provocation tests. RESULTS: A sample of 598 male workers with a mean age of 36.5 years (SD = 10.0) was analyzed. The mean length of exposure was 10.1 years (SD = 7.4). The overall prevalence of pneumoconiosis was 4.5%. Chronic bronchitis (CB) and X-ray profusion were significantly related to the quartiles of length of exposure (trend tests: P = 0.0055 and P < 0.001, respectively). There was a significant risk of having an abnormal FVC and FEV(1) with the presence of pneumoconiosis (OR = 4.63 CI 1.40-13-23, OR 3.34 CI 1.03-9.26, respectively). Workers exposed to resins compared with controls showed no differences in relation to spirometry, respiratory symptoms and bronchial reactivity. CONCLUSIONS: There were significant associations between length of exposure CB and prevalence of profusion 1/0 or above. There was also a significant association for pneumoconiosis versus and abnormal FVC and FEV(1). Foundry workers currently exposed to resins did not show an excess of respiratory symptoms, abnormal spirometry or increased bronchial reactivity.

Pneumoconiosis after sericite inhalation.

BACKGROUND: Between 1997 and 1999 three sericite plant workers in Parana, Brazil, were diagnosed with pneumoconiosis. AIMS: To investigate and describe the radiological, clinical, and pathological changes in miners and millers exposed to sericite dust with mineralogical characteristics of inhaled dust. METHODS: The working premises were visited to examine the sericite processing and to classify the jobs according to make qualitative evaluation. Respirable dust was collected and the amount of crystalline silica and particle size distribution were measured. Forty four workers were examined by a standard questionnaire for respiratory symptoms, spirometry, and chest x ray. Material from an open lung biopsy was reviewed for histopathological and mineralogical analysis, together with sericite samples from the work site to compare the mineral characteristics in lung lesions and work area. RESULTS: Respirable dust contained 4.5-10.0% crystalline silica. Particle size distribution showed a heavy burden of very fine particles (23-55%) with a mean diameter of <0.5 microm. Mean age of sericite miners was 41.0 (11.9) and mean number of years of exposure was 13.5 (10.1). In 52.3% of workers (23/44), chest radiographs presented a median category of 1/0 or above, and 18.2% (8/44) had a reduced FEV1. There was a significant association between exposure indices and x ray category. Histological studies of the lung biopsy showed lesions compatible with mixed dust fibrosis with no silicotic nodules. x Ray diffraction analysis of the lung dust residue and the bulk samples collected from work area showed similar mineralogical characteristics. Muscovite and kaolinite were the major mineral particle inclusions in the lung. CONCLUSION: Exposure to fine sericite particles is associated with the development of functional and radiological changes in workers inducing mixed dust lesions, which are distinct histologically from silicosis.

Non-malignant asbestos-related diseases in Brazilian asbestos-cement workers.

BACKGROUND: Production of asbestos-cement products in Brazil started in the 1940s, peaked in the 60-70s and is still an active industry. This study was designed to assess the non-malignant effects of asbestos exposure in the asbestos-cement industry in Brazil. METHODS: A group of 828 former asbestos-cement workers enrolled in a cross-sectional and cohort study of respiratory morbidity, submitted to a detailed occupational history, respiratory symptoms questionnaire, spirometry, PA chest x-ray, and high resolution computed chest tomography (HRCT). Asbestos exposure was assessed by years of exposure, cumulative exposure (a semi-quantitative method), and latency time from first exposure. Asbestosis and pleural thickening were assessed according to HRCT criteria. RESULTS: Asbestosis was present in 74 (8.9%) and pleural thickening in 246 (29.7%). Using the HRCT as the "best available evidence", it was shown that were more false negatives than false positives in the x-ray readings for parenchymal (21.6% false negatives, 4.2% false positives) and pleural (26.0% false negatives, 14.4% false positives) diseases due to asbestos. Latency time from first exposure was the best predictor for both asbestosis and pleural thickening. Subjects in the higher exposure groups presented lower levels of lung function. Obstructive defects were significantly related to smoking, shortness of breath, body mass index, and age, whereas restrictive defects were related to asbestosis, shortness of breath, and latency time. Chronic bronchitis increased with latency time in the three smoking groups and was significantly related to pleural thickening (OR 1.56 (1.00-2.42)). Shortness of breath was significantly associated with body mass index and pleural thickening (OR 1.30 (1.24-2.09)). CONCLUSIONS: Pleural thickening and asbestosis showed a significant association with latency time and exposure. FVC and FEV(1) decreased across increasing profusion with an added effect of pleural thickening. There was a significant and independent effect of exposure on lower levels of FVC and FEV(1). Obstructive defects were mainly related to smoking and restriction to asbestosis. Dust exposure and smoking were synergistic in increasing chronic bronchitis and shortness of breath report. Shortness of breath report was also related to pleural thickening and higher body mass index.

Asbestos-Related Pleural Thickening is Independently Associated With Lower Levels of Lung Function and with Shortness of Breath.

This study investigated the relative contribution of asbestos-related pleural thickening (PT) to lung function indices and to respiratory symptoms. A group of 828 former asbestos cement workers enrolled in a cross-sectional and cohort study of respiratory morbidity and submitted to a detailed occupational history, respiratory symptoms questionnaire, spirometry, postero-anterior chest x-ray, and high-resolution computed chest tomography (HRCT). Asbestos exposure was assessed by years of exposure (a semi-quantitative method), cumulative exposure, and latency time from first exposure. Smoking was assessed in pack-years. PT and asbestosis were assessed according to HRCT criteria. Statistical analysis included descriptive analysis, univariate and multivariate analysis of variance for comparisons of factors related to PT, stepwise multiple regression analysis for continuous dependent variables, and logistic regression analysis for dichotomous dependent variables. Mean age was 51.4 (SD 10.5) years, mean years of exposure 12.4 (SD 8.8), mean cumulative exposure 79.9 (SD 68.5), and mean latency time 25.2 yr (SD 10.4). Of the 828, 238 (28.7%) were smokers, 288 (34.8%) former smokers, and 302 (36.2%) nonsmokers. PT was present in 246 (29.7%) and asbestosis in 74 (8.9%); 97 (11.9%) had shortness of breath of Grade III or more. PT subjects had lower height-adjusted forced vital capacity (FVC) and forced expiratory volume in I s (FEV1) and lower FEV1/FVC% (p < .00001 for all). Variables significantly related to PT were age (p < .000 1), years of exposure (p < .0000 1), cumulative exposure (p < .00001), latency time (p < .00001), pack-years (p < .0000 1), and asbestosis (p < .00 1). In a multiple stepwise regression model, after controlling for confounders, height adjusted FEV1 and FVC were in versely and significantly associated with PT, mainly when associated with asbestosis. A logistic regression model with shortness of brea th as the dependent va riable, con trolled for confounders, showed that PT was significa ntly associated with the symptom, even without asbestosis. In conclusion, PT is independently associated with lower va lues of FEV1 and FVC. PT is also independently associated with an increased risk of shortn ess of breath report. PT should be considered as a disease for clinical follow up and for compensa tion claims.

Teste de provocacao bronquica com carbacol no diagnostico de asma. Relato de casos e comentarios. / Bronchial provocation test with carbachol in the diagnosis of asthma. Report of cases and comments

O teste de provocacao bronquica com carbacol e usado para demonstrar a presenca de hiperreatividade bronquica, a qual e universal entre os portadores de asma bronquica. Isto permite o diagnostico ou nao da doenca em diversas situacoes clinicas frequentes. Atraves do relato de casos e revisao bibliografica, e demonstrada a importancia deste teste em casos de:suspeita de asma de inicio recente, com exame clinico-funcional normal; tosse persistente e dispneia como manifestacoes isoladas de asma; diagnostico diferencial da asma bronquica e cardiaca; asma ficticia; e refluxo gastresofagiano simulando asma

Mecanica pulmonar nas doencas neuromusculares. / Lung mechanics in neuromuscular diseases

Foram estudados 26 pacientes, nao-selecionados por sintomas repiratorios portadores de distrofia miotonica (quinze), esclerose lateral amiotrofica (quatro), miastenia gravis (dois), e outros (cinco).A media de idade foi 38,6 +/- 17,9 anos. Foram realizadas espirometria curvas fluxovolume curvas pressao-volume, VVM e pressoes respiratorias maximas de boca. A pressao expiratoria maxima estava reduzida em todos os pacientes, enquanto a pressao inspiratoria maxima estava normal em dezesseis dos pacientes (61%). A VVM e a CV estavam reduzidas, do modo proporcional em treze e onze pacientes, respectivamente. A curva pressao-volume pulmonar estava desviada para a direita e para baixo em quinze pacientes. A pressao transpulmonar na CFR, ao contrario do que ocorreu na CPT, estava reduzida. Dos parametros da espirometria estatica, o VRE foi o mais alterado e se correlacionou diretamente com a pressao transpulmonar na CRF e inversamente com a pressao transpulmonar na CPT. Esta mesmas correlacoes foram mantidas para a CV. Os fluxos expiratorios corrigidos para o volume pulmonar foram normais.Os fluxos inspiratorios maximos estavam significativamente reduzidos. Em conclusao, o comprometimento funcional dos musculos respiratorios em doencas neuromusculares e frequente. A restricao resultante provavelmente se deva a perda do tonus muscular da caixa toracica, com alteracoes secundarias nas propriedades elasticas do pulmao

Teste de reatividade bronquica com carbacol - resposta em normais e asmaticos. / Bronchial reactivity test with carbachol - response in normal and asthmatic patients

Cinquenta individuos, 25 normais e 25 asmaticos, foram estudados com doses crescentes de carbacol por nebulizador de jato A resposta foi medida por espirometria determinando-se a dose de provocacao que causou 15% de queda do VEF1,0(DP15). A media geometrica foi 3,89 +/- 0,30 em normais e 2,34 +/- 0,72 nos asmaticos (p<0,01 teste de Wilcoxon). A dose de 2,0 mg separou os dois grupos com sensibilidade e especificidade de 95%. Respostas com doses de carbacol entre 2,0 e 4,0 mg foram encontradas em tres de cinco normais que tinham parentes com asma, e em nenhum dos demais normais. Concluimos que a presenca de reatividade bronquica anormal pode ser estabelecida de maneira simples, inalando-se doses de carbacol de ate 4,0 mg