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Biomedical subjects

B Saia

Publications and source records attributed to B Saia.

At least 19 recordsLinked to original sources

Repeated case-control studies as a method of surveillance for asthma in occupations.

Our aim was to establish whether the case-control design may be applied in surveillance for occupational asthma. In a region with intensive manufacturing industries, we carried out one case-control study from 1974 to 1978 and another from 1989 to 1993; 325 and 387 pairs of cases of asthma and of age- and sex-matched control subjects, respectively, were selected. Current risks were found to be higher than past estimates for painters, farmers, millers/bakers, textile, wood/ furniture, and chemical workers. High risks for asthma have recently appeared in leather, polyurethane plastics, hospital and food industry workers, welders, and shoemakers. It is concluded that the case-control approach may be used to describe variations in asthma risk by occupational categories and time. A method to measure the efficiency of the diagnostic process for occupational asthma is also proposed.

Adolescent↗

Pulmonary impairment in workers exposed to silicon carbide.

Two hundred and sixty seven workers employed in the manufacture of silicon carbide (SiC) were examined to determine the effects of exposure to contaminants (SiC, quartz, and SO2) in the workplace on pulmonary function. No exposure concentrations exceeded the current permissible limits. Ten subjects (3.7%) showed rounded opacities (profusion greater than or equal to 1/0). Two subjects employed only in the final stages of the production process and not exposed to crystalline silica showed opacities (profusion q1/0 and q2/1) on x ray film suggesting a role of SiC in the genesis of interstitial lung disease. Chest abnormalities on x ray film were correlated with cumulative exposure to dust and pulmonary function was affected by cumulative dust exposure, profusion of opacities, and smoking. It is concluded that the current standards do not provide adequate protection against pneumoconiosis and chronic pulmonary disease in this industry.

Carbon↗

Mortality of workers compensated for silicosis during the period 1959-1963 in the Veneto region of Italy.

After reports appeared from other countries indicating an excess risk of lung cancer among silicotics, a cohort of workers compensated for silicosis during the period 1959-1963 in the Veneto region of Italy was constructed and followed for mortality through 1984. The results of the study showed a large mortality excess for infectious diseases (180 observed versus 9.5 expected), due to silicotuberculosis, and for diseases of the respiratory system (270 observed versus 33.5 expected) due to silicosis. An elevated standardized mortality ratio of 239 (70 observed versus 29.3 expected) from lung cancer was also detected. An increasing pattern was observed with time since first exposure, while the relationship with employment category and duration of exposure was less clear-cut. The lung cancer excess was also strongly associated with cigarette smoking, there being a dose-response relationship with daily cigarette consumption. The study confirms the results from other epidemiologic studies on silicotics which show this pathological condition to be associated with increased lung cancer mortality.

Humans↗

Age characteristics of mesothelioma incidence in the general population of the province of Padova, 1965-1976.

Twenty-four incidental cases of mesothelioma, diagnosed in the province of Padova during the period 1965-1976, were analyzed according to age characteristics. The results show that the incidence rate increases in the general population under study at the same rate as in other populations occupationally and non-occupationally exposed to carcinogenic fibers according to the time since first exposure. This finding suggests a similar neoplastic process independent of age, in different environmental situations.

Adult↗

Study of immunological parameters in farmer's lung.

A cross-sectional epidemiological study was carried out on 2932 farmers (response rate 92%) living in Northern Italy. A questionnaire on respiratory symptoms was supplied, chest X-ray taken and simple spirometry tests made. Thirty-nine subjects reported attacks of breathlessness associated with fever after exposure to mouldy hay; thirty-six had a clinical history of farmer's lung and X-ray and/or respiratory function changes indicative of chronic farmer's lung; 113 were classified as having bronchial asthma. These 118 subjects and a random sample of 131 non-symptomatic subjects were examined by intracutaneous skin tests and double diffusion precipitation tests with antigens associated with farmer's lung. All sera positive by precipitation were examined by immunoelectrophoresis, counterimmunoelectrophoresis, and C1q binding test, and Bovine conglutinin test in solid phase for the detection of circulating immunocomplexes. 27.8% cases of chronic farmer's lung, 4.4% of cases of bronchial asthma and 2.3% of non-symptomatic subjects showed precipitating antibodies against farmer's lung antigens. Of the precipitin-positive subjects, the majority had precipitating antibodies against Micropolyspora faeni. No differences in immunoelectrophoregrams in number and pattern of precipitation arcs for M. faeni were found between chronic farmer's lung and bronchial asthma subjects. Circulating immune complexes were present in 50% of chronic farmer's lung patients, 40% of those with bronchial asthma and 33.3% of non-symptomatic subjects. Three farmer's lung subjects (9.3%) showed immediate skin-test reactions to rural environmental allergens.

Antibody Formation↗

Epidemiological study of pneumoconiosis in the Italian poly(vinyl chloride) industry.

Among 1216 workers employed in a poly(vinyl chloride) production factory, 20 cases of pneumoconiosis were found. None of these workers had had previous exposure to organic or inorganic dusts; 731 had been exposed to PVC dust (employed in drying, sacking and blending of polymer) and 485 had been exposed to monomer alone. Chest x-ray films were read by two independent physicians utilizing the ILO/UC Pneumoconiosis Classification, 1971. X-ray abnormalities were characterized by limited profusion, irregular type and low gravidity; in a small percentage of cases these were associated with slight restrictive respiratory function impairments. All 20 workers with PVC-induced pneumoconiosis had been exposed to high PVC dust pollution for at least five years. Mild nonspecific alterations (profusion of 0/1 class) were found both in the group exposed to PVC dust and in the group exposed to VCM alone. Such changes (observed in 388 cases, 31.9% of the whole population), are related mainly to age and smoking habits, and the role of exposure is minor.

Adult↗

Descriptive epidemiology of non-Hodgkin's lymphoma in the province of Padova, 1970-1974.

The age-standardized incidence rates of non-Hodgkin's lymphoma in the province of Padova during the period 1970-1974 were 3.19/10(5)/year for males and 1.60/10(5)/year for females. These rates are similar to those found in other industrialized countries and slightly higher than in the province of Torino. An increasing trend with age is described, beginning in the age group 35-44, while low rates were found in younger ages in both sexes. No relevant pattern was shown in the geographical distribution of cases, and no observed/expected ratio was significant in any of the administrative districts considered. The influence of environmental factors and the limitations due to uncertain diagnostic criteria and the small size of the population considered are discussed.

Adolescent↗

Polyvinyl chloride pneumoconiosis: epidemiological study of exposed workers.

Among 1216 workers who were employed in a polyvinyl chloride production factory and who had had no previous dust exposure elsewhere, 20 cases of pneumoconiosis were found. Chest x-ray abnormalities were characterized by limited profusion, irregular type and low gravity. All 20 workers had been exposed to high PVC dust levels. The chest x-ray changes were observed after a minimum exposure of five years and, in a small percentage of cases, were associated with slight restrictive respiratory function impairments. Moreover, in the whole group of workers 388 cases (31.9%) were found with non-specific x-ray abnormalities mainly related to age and smoking.

Adult↗

[Chronic broncopneumopathy and pneumoconiosis in workers employed in phosphoric acid production (author's transl)].

Thirty-five subjects employed in a phosphoric acid producing plant were studied by the authors. The investigation included: history, according to the C.E.C.A. questionnaire for chronic bronchitis and emphysema; physical examination, chest X-ray spirometry and lung diffusing capacity for carbon monoxide by the steady state method (DLCOSS). High prevalence of chronic bronchitis (45.7%), obstructive spirometric impairment (37.1%), and decreased values of DlcoSS (31.4%) were detected. Two subjects were found to be affected with p 1/0 and 7 with p 0/1 pneumoconiosis. Such findings were significantly related to the lenght of working activity as well as to dust and gaseous fluoride (hydrofluoric acid, hexafluorosilicic acid and silicon tetrafluoride) exposure.

Adult↗

[Epidemiologic evaluation of isocyanate immediate irritative action: 'one day effect' control (author's transl)].

Nineteen MDI exposed workers showed ventilatory changes, after eight hour exposure, mainly involving upper respiratory airways; the changes reversed following a bronchodilator aerosol. An incomplete recovery of VC was found in some subjects; therefore, the possibility of changes in the lung elastic recoil forces was hypothesized. No statistically significant differences were found as to occupation and smoking habit, which suggests that even low MDI concentrations could be enough to give rise to acute effects. The greater impairment found in subjects who were already affected by morning time emphasizes the necessity that such subjects were not employed in their specific work.

Adult↗