Summary The objective of this study was to investigate if the dust in a mill producing soft paper tissue caused respiratory symptoms or impaired respiratory function. Using a questionnaire and spirometry, 355 persons were examined. They were divided into three groups according to present exposure to dust; low (< 1 mg/m3), moderate (1–5 mg/m3) and heavy (> 5 mg/m3). There was a dose-dependent increase of symptoms from the upper respiratory tract. However, coughing and coughing with phlegm were not found to be more common among persons with heavy exposure compared to those with low exposure to the dust. There was no difference in FEV, or FVC during a work shift. Persons with long-term (> 10 years) and heavy exposure to dust seemed to have impaired respiratory function compared to those with low and/or short-term exposure to the dust. 相似文献
Summary Among 701 Copenhagen plumbers we examined the lung function of 23 never smokers, who had removed asbestos insulation and intermittently been exposed to high levels of asbestos for about 25 years without being exposed to welding fume. The plumbers had significantly lower TLC, MEF25, MEF50, closing volume and closing capacity in comparison to 23 never smoking electricians without asbestos exposure. There was no reduction in TLCO. Pulmonary clearance of aerosolized 99mTc-DTPA was normal indicating that the asbestos had not induced increases in pulmonary epithelial permeability. However, in 11 of the 23 plumbers the 99m-Tc-DTPA ventilation scintigrams had a slightly irregular and spotty appearance, which together with the results of the lung function tests are suggestive of small airways' dysfunction. None of the subjects had symptoms or clinical signs of lung disease. 相似文献
BACKGROUND: Reduction of house dust mite allergens in the domestic environment can play an important part in reducing sensitization and in the amelioration of symptoms in atopic individuals. Chemical and physical methods have been tried with varied levels of success. The present paper presents a novel electrostatic way of destroying Der p 1, the major mite allergen. OBJECTIVE: To assess the efficacy of negative Trichel, negative continuous glow, positive pulse and positive continuous glow corona in destroying Der p 1. To determine whether ozone has any effect on the integrity of Der p 1 in the experimental conditions present. METHODS: A simple point-to-plane apparatus was used to irradiate samples of Der p 1 for periods of 1, 15, 30, 45, 60, 120, 180, 240 and 300 min. Controls were exposed to the atmosphere with no corona products present for the equivalent time. The effect of the corona by-product ozone was investigated alone by exposing samples of Der p 1 to molecular ozone for 60 min. Der p 1 concentration was quantified by two-site monoclonal antibody ELISA. RESULTS: High current negative glow resulted in a 67.37% reduction in Der p 1 concentration after 300 min compared with a 50.5% reduction from a low current Trichel regime. High current positive glow corona gave a reduction of 25.22% while a low current positive pulse corona caused a 13.72% reduction after 300 min. All these reductions were statistically significant (P < 0.05) compared with unexposed controls. Negative corona always gave greater percentage reductions in Der p 1 concentration for each time exposure investigated. The pattern of percentage reduction follows an exponential rise to maximum relationship in respect to time. Samples of Der p 1 were not affected by exposure to molecular ozone. CONCLUSION: These data indicate corona products to be a powerful new method of destroying Der p 1 allergen that is not dependent on the presence of the oxidizing corona product ozone. 相似文献
The aim of our study was to analyze the clinical features, particularly the age at symptom onset, of allergic subjects (asthma and/or rhinitis) on the basis of the etiologic elements (sensitization to various allergens). We identified a group of monosensitized patients and a group of polysensitized patients. Within these groups, we identified subgroups of subjects monosensitized to one of the five main allergenic mixes (mites, Gramineae, trees, Parietaria, and Artemisia) and five subgroups of patients sensitized nonexclusively, that is, polysensitized, to the same allergens. The comparison between the two groups and among the various subgroups enabled us to conclude that:
1)
mono- and polysensitized patients present some clinical features so different as to constitute two clearly distinct clinical groups
2)
analysis of the clinical features associated with the sensitization to a specific allergen brings us to significantly different conclusions when we consider subgroups of monosensitized or polysensitized patients
3)
the parameter "age at symptom onset" shows great heterogeneity among both the mono- and the polysensitized subgroups - in particular, the great differences in mean age among the monosensitized subgroups (trees>y4rtemi.s(fl>Pflrie/flria>Gramineae>mites) appear very interesting and are open to various interpretative hypotheses
4)
unlike the polysensitized group, in the monosensitized group and subgroups, mean age is similar between men and women and, only for tree- and parietaria -monosensitive patients, also between asthmatic and rhinitic subjects.