Search PubMed⌕ Search

Biomedical subjects

D Casula

Publications and source records attributed to D Casula.

At least 19 recordsLinked to original sources

Dust exposure, respiratory symptoms, and longitudinal decline of lung function in young coal miners.

OBJECTIVES: To study the role of dust exposure on incidence of respiratory symptoms and decline of lung function in young coal miners. METHODS: The loss of lung function (forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory flow (MEF), carbon monoxide transfer factor (TLCO)) with time and the incidence of respiratory symptoms in 909 Sardinian coal miners (followed up between 1983 and 1993 with seven separate surveys) has been compared with the past and current individual exposures to respirable mixed coal dust. Multiple linear and logistic regression models were used simultaneously controlling for age, smoking, past occupational exposures, and other relevant covariates. RESULTS: According to the relatively low dust exposures experienced during the follow up few abnormal chest x ray films were detected. In the cross sectional analysis of initial data, significant associations between individual cumulative exposure to dust, decrements in FEV1 and MEFs, and increasing prevalence of respiratory symptoms were detected after allowing for the covariates included in the model. The yearly decline of FVC, FEV1, and single breath carbon monoxide transfer factor (TLCO/VA) was still significantly related to the individual exposure to dust experienced during the follow up, even after allowing for age, smoking, initial cumulative exposure to dust, and initial level of each functional variable. In logistic models, dust exposure was a significant predictor of the onset of respiratory symptoms besides age and smoking. CONCLUSIONS: The results show that even moderate exposures to mixed coal dust, as in our study, significantly affect lung function and incidence of symptoms of underground miners. Although the frequency of chest x ray examination might be fixed at every three or four years, yearly measurements of lung function (spirometry, MEFs, and TLCO) are recommended for evaluation of the respiratory risk from the coal mine environment to assess the need for further preventive interventions.

Age Factors↗

Mortality from lung cancer among Sardinian patients with silicosis.

The mortality of 724 subjects with silicosis, first diagnosed in 1964-70 in the Sardinia region of Italy, was followed up through to 31 December 1987. Smoking, occupational history, chest x ray films, and data on lung function were available from clinical records for each member of the cohort. The overall cohort accounted for 10,956.5 person-years. The standardised mortality ratios (SMRs) for selected causes of death (International Classification of Diseases (ICD) eighth revision) were based on the age specific regional death rates for each calendar year. An excess of deaths for all causes (SMR = 1.40) was found, mainly due to chronic obstructive lung disease, silicosis, and tuberculosis with an upward trend of the SMR with increasing severity of the International Labour Office (ILO) radiological categories. Twenty two subjects died from lung cancer (SMR = 1.29, 95% confidence interval (95% CI) = 0.8-2.0). The risk increased after a 10 and 15 year latency but the SMR never reached statistical significance. No correlation was found between lung cancer and severity of the radiological category, the type of silica (coal or metalliferous mines, quarries etc), or the degree of exposure to silica dust. A significant excess of deaths from lung cancer was found among heavy smokers (SMR = 4.11) and subjects with airflow obstruction (SMR = 2.83). A nested case-control study was planned to investigate whether the association between lung cancer and airway obstruction was due to confounding by smoking. No association was found with the ILO categories of silicosis or the estimated cumulative exposure to silica. The risk estimate for lung cancer by airflow obstruction after adjusting by cigarette consumption was 2.86 for a mild impairment and 7.23 for a severe obstruction. The results do not show any clear association between exposure to silica, severity of silicosis, and mortality from lung cancer. Other environmental or individual factors may act as confounders in the association between silicosis and lung cancer. Among them, attention should be given to chronic airways obstruction as an independent risk factor for lung cancer in patients with silicosis.

Aged↗

Mechanisms of PCBs mixture toxicity on isolated rat hepatocytes.

Exposure of isolated hepatocytes to a polychlorinated biphenyl mixture induced a rapid loss of cell viability. The effect was not dose-dependent. The biochemical effects in the cellular toxicity did not involve glutathione content, protein sulfhydryl groups and lipid peroxidation. A transient increase in cytosolic Ca2+ was observed after exposing the hepatocytes to the polychlorinated biphenyl mixture. Our findings indicate that polychlorinated biphenyls are able to kill hepatocytes and suggest that elevation of cytosolic Ca2+ concentration could be responsable of the toxicity.

Animals↗

Blood lead levels in children of S.W. Sardinia.

The purpose of the present study was to make a preliminary evaluation of blood lead levels in school-aged children from three towns of southwestern Sardinia, Portoscuso, S. Antioco and Calasetta, the first of which is very close to a large industrial complex. Blood lead concentration was determined in venous blood samples by graphite furnace atomic absorption spectrophotometry. The survey revealed that children residing in the town of Portoscuso had higher mean blood lead levels (12.7 micrograms/dl) than children of the same age residing in S. Antioco and Calasetta (8.3 and 8.4 micrograms/dl respectively) and that levels were slightly higher in males than in females. This difference is suggested to be a result of the greater fallout of industrial pollutants in the area of Portoscuso.

Child↗

[Isoflurane pollution in operating rooms].

In three operating rooms of a Sardinian hospital, the Authors have measured the air levels of isoflurane using static samplers. Anaesthetic mean daily concentrations ranged from 3.5 to 41.5 ppm in room A, from 4.1 to 24.4 ppm in room B, from 9.5 to 30.4 ppm in room C above all depending on the length and the number of surgical operations. The Authors emphasize the need of suitable prevention measures.

Air Pollutants, Occupational↗

[Normal values of methemoglobinemia in a sample of Sardinian workers].

The susceptibility of hemoglobinic iron to oxidation in the ferric form by action of numerous industrial substances, suggested the use of metHbemia dosage in biological monitoring of professional exposure to such substances. In order to have useful reference values, the metHbemia of 975 male workers, from various parts of Sardinia, was measured at least 12 hours after last work shift. 95% of the examined population had metHbemia values lower than 0,86% of total Hb; such result has been compared with other normal values, found in literature and likely causes of the differences between such values have been discussed. On the basis of our results and on the examination of literature an intervention prospectus is suggested for biological monitoring of exposure to methemoglobinising substances.

Adult↗

[Determination of the pneumoconiosis hazard in the cork industry].

The AA. have carried out an epidemiological investigation in order to control the prevalence of chronic respiratory diseases on a group of 385 people working in several cork industries in North Sardinia. At the same time an environmental investigation has been carried out. Standard questionnaire (CECA questionnaire) for chronic bronchitis and pulmonary emphysema, standard chest X-ray film, spyrographic investigation, ECG and sputum analysis for acid resistent bacteria have been used for epidemiological investigation. Environmental dust concentration and individual dust exposure, environmental concentration of sulphur oxides, nitrogen oxides, carbon mono- and dioxide, ammonia nad microclimatic conditions have been studied. Examination of medical data shows only a low degree of respiratory pathology in contrast with results of other authors, probably because of different methods used for epidemiological investigation and data interpretation and because of different environmental and working conditions.

Air Pollutants↗

[Environmental dust in a plant for the production of polyvinyl chloride].

The results of an investigation on environmental dust concentration and individual dust exposure in a drying and sacking section of an "emulsion" and "suspension" PVC plant are reported; data on environmental concentration and individual dust exposure have been obtained by gravimetric techniques using similar personal and static dust samplers. Morphology and particle size distribution have been studied by electron microscopy on airborne dust specimens. Morphological analysis showed remarkable differences concerning shape and size between particles sampled in the "suspension" polymer and "emulsion" polymer sacking sections. Remarkably high mean values concerning dustness have been observed: 1.30 mg/m3 (min. 0.15; max. 18.4 mg/m3) for environmental concentration and 5.39 mg/m3 (min. 0.28; max. 45.6 mg/m3) for individual exposure.

Air Pollutants↗