Tag: forced-oscillation technique

Respiratory Symptoms and Lung Function in Animal Feed Workers: Comment

They showed changes in airway responsiveness and airway inflammation in rats after challenge to an aerosol of endotoxin. Furthermore, a significant increase in secondary release of tumor necrosis factor, a proinflammatory marker, after endotoxin challenge was observed. This indicates that the airway inflammation caused by endotoxin exposure might be mediated through tumor necrosis factor release. A significantly higher prevalence of most (chronic) respiratory symptoms was found in the exposed workers compared with control workers. Separate…

Respiratory Symptoms and Lung Function in Animal Feed Workers: Conclusion

Our linear regression revealed similar B-values for flow volume parameters with cumulative exposure in the same order of magnitude but probably due to a smaller population, the level of significance was not always reached. Kennedy et al showed that lung function (FEVi, FEVi percent) and respiratory symptoms (byssinosis and chronic bronchitis) were related to present exposure in cotton workers; we also observed a concentration-dependent decrease in lung function with increasing present exposure. Correlation of lung…

Respiratory Symptoms and Lung Function in Animal Feed Workers: Discussion

In general, endotoxin levels in the dust depend on a number of factors, such as the nature of the dust, land of origin of the product, conditions during transport, the particle size during processing, temperature, and humidity. For the workers, particle size seems to be the most important factor involved in the endotoxin/ dust ratio. In general, large dust particles will contain relatively small ratios of endotoxin whereas small dust particles will contain a relatively…

Respiratory Symptoms and Lung Function in Animal Feed Workers: Respiratory Symptoms and Lung Function

Chronic bronchitis was significantly related to cumulative dust exposure, shortness of breath was related to present dust and present endotoxin exposure (Table 5), whereas wheezing was related to cumulative dust and endotoxin measures. Since both respiratory symptoms and lung function were different among exposure categories with respect to present dust exposure, we investigated whether symptoms were related to lung function parameters using two logistic regression analyses (one with flow volume parameters, one with impedance parameters)….

Respiratory Symptoms and Lung Function in Animal Feed Workers: Respiratory Symptoms

Differences between exposure groups were most pronounced for FEF25. Interestingly, all impedance parameters were significantly different between exposure groups. R8 and fo increased at higher exposure while X8 decreased with higher exposure (Table 3). Frequency dependence of oscillatory resistance became more negative with increasing exposure. Roughly, similar differences between exposure groups and lung function parameters were observed when workers were stratified into three groups with respect to endotoxin exposure. Difference in effects on lung function…

Respiratory Symptoms and Lung Function in Animal Feed Workers: Pulmonary Function—Present Exposure

Symptoms (cough, phleghm, chronic bronchitis, breathlessness, wheezing, asthmatic attacks) were included if a subject had positively responded to a question in a category. Three separate logistic regression analyses were performed with the respiratory symptom as the dependent variable and the confounders (age, height, pack-years) and spirometric or impedance or exposure parameters as the independent variables. Exposure was not regarded as a confounder in this relationship. Subjects using inhalation drugs (four in the exposed group only)…

Respiratory Symptoms and Lung Function in Animal Feed Workers: Data Handling and Analysis

Impedance measurements were always performed prior to registration of flow volume curves to avoid the influence of forced expiratory maneuvers on the bronchial tone. All subjects were measured at least 4 h after beginning their shift since acute respiratory effects of endotoxin exposure are measurable 4 h after exposure. Lung function measurements were obtained from 205 male workers: 60 office staff (group l=not exposed), 145 blue collar workers (group 2=exposed). Since three spirometric measurements and…

Respiratory Symptoms and Lung Function in Animal Feed Workers: Lung Function Measurements

Impedance measurements were performed on equipment described by Landser et al. Briefly, the seated subject, wearing a noseclip, supports the cheeks with his hands and breathes quietly via a tube. A pseudorandom noise pressure signal containing all harmonics of 4 up to 52 Hz is applied at the mouth by means of a loudspeaker. Mouth pressure and flow signals are recorded by transducers with identical frequency characteristics (Validyne MP45) and analyzed by spectral analysis techniques….

Respiratory Symptoms and Lung Function in Animal Feed Workers: Production Process

Raw materials arrive by ship or by truck. Mainly grains (especially corn, wheat, and barley), other vegetable products such as cassava, tapioca, and waste products from the food industry are used. The raw materials are cleaned, stored in silos, and mixed in a batch process. Fats, molasses, vitamins, and minerals are added in small quantities. The mixture is stored again in silos, usually after being pressed to pellets. The product is transported to the customer…

Respiratory Symptoms and Lung Function in Animal Feed Workers

Long-term exposure to organic dust is known to cause respiratory symptoms and airflow obstruction, mostly studied in grain workers and in cotton industry workers. In workers exposed to grain dust, significant dose-response relationships were reported by Huy et al for chronic phleghm production, breathlessness on exertion, FEVi, FVC, and total dust exposure in workers. Few studies in the animal feed industry have been reported. One study showed both acute, across-shift, and preshift effects of feed…