Insulation workers in Belfast. 2. Morbidity in men still at work.

Langlands, Jean H. M., Wallace, W. F. M., and Simpson, Marion J. C. (1971). Brit. J. industr. Med., 28, 217-225. Insulation workers in Belfast. 2. Morbidity in men still at work. Two hundred and fifty-two (93 Y.) of the insulation workers in Belfast were examined by chest x-ray, questionnaire, clinical examination, and tests of respiratory function. The frequency of chest x-ray abnormality, lung field or pleural, increased from 13 % in men who had worked for less than 10 years to 85 % in men who had worked for 30 or more years in the industry. Pleural calcification was found in 15 x-rays. There was evidence suggesting that some men had pleural fibrosis or calcification due to exposure to asbestos in childhood. Rales were present in 61 % and clubbing in 11 % of men with lung field abnormality, but these were not common when the x-rays showed only pleural abnormality. Where the lung fields were involved there was a restrictive defect with impairment in lung function most marked in the forced vital capacity and single breath carbon monoxide transfer factor, but where the pleura was involved without lung field involvement there was a tendency to impairment of ventilatory function with a normal transfer factor. Cigarette smoking was associated with a greater impairment of lung function than was x-ray abnormality.