Asbestosis in the industries of the Barcelona area

This presentation is the result of the survey of eight industries with asbestosis risk in the Barcelona area (two of fibro-cement, three of auto brakes, two of textiles, and one of insulation materials). Of 1,472 workers, 271 or 18.5% have asbestosis. Pleural involvement in asbestosis is twice as common as that of the lung, 15.7% versus 8.5%. Pulmonary asbestosis without pleural participation is seen in only 2.6% of cases. Pleural plaques, calcified and not calcified, are detected in only a few cases. There is a definite correlation between the incidence of asbestosis and the exposure time: from 1% in the group of workers with less than five years of exposure up to 64.58% for those with 30 or more years of exposure. Clinical symptoms (cough, and/or expectoration, and/or dyspnea) were present in 68% of the studied population. Pulmonary crepitations are the most significant physical sign detected, observed in one quarter to one third of the patients. Pulmonary function tests in asbestos workers revealed restrictive and mixed type syndromes in 17% of the cases and obstructive syndrome in 36%. The percentages for those workers without asbestosis are 9% and 16%, respectively. It seems, therefore, that a bronchial factor plays a role in asbestosis. The bronchial pathology would be manifested clinically by the appearance or the exaggeration of the chronic bronchitis symptoms, and physiologically by the presence of the obstructive syndrome. There is no doubt that smoking enhances the incidence of asbestosis, aggravates the respiratory symptoms in those affected, and is a cause of further deterioration of pulmonary function.

Aryl hydrocarbon hydroxylase induction in mitogen-stimulated lymphocytes by benzanthracene or cigarette tars adsorbed to asbestos fibers

Human mitogen-stimulated lymphocytes, cultured in the presence of amosite asbestos (AS), demonstrated a slight increase in aryl hydrocarbon hydroxylase (AHH) activity compared with non-induced (control) cultures (P = 0.005). A much greater increase in enzyme activity occurred following addition of the inducers benzanthracene (BA) or cigarette tars (CT) to cell cultures (P less than 0.001 in both instances). Significant enzyme induction also occurred when AS fibers were first preincubated with CT or BA, washed with acetone, then added to lymphocyte cultures (P less than 0.003 in all instances). This increase in AHH activity was not as great, however, as the induction observed when BA or CT was added to cell cultures. No further increase in enzyme activity was noted when AS and CT or AS and BA were simultaneously added to culture lymphocytes (P greater than 0.070 in all instances). The results demonstrate that polycyclic aromatic hydrocarbons (PAH), such as BA and other components of CT, are adsorbed and transported by amosite AS particles. These AS-PAH complexes are capable of inducing AHH in cultured human lymphocytes.