Abstract

A controlled trial in coalminers under the age of 50 in South Wales with sputum-negative, early complicated pneumoconiosis was used to compare three regimes: (1) chemotherapy (rest in hospital and 1 g. streptomycin, 200 mg. INH, 10 g. PAS, for 3 months; then 200 mg. INH, 10 g. PAS for 9 months); (2) rest (in hospital for 3 months); and (3) a working group. The initial and three-year radiographs were assessed by two methods in 173 (96%) of the 180 men entering the trial. No beneficial effect of chemotherapy was demonstrated and this factor was not related to the completeness of the chemotherapy. The variation between individuals in the rate of progression and in the development of new shadows was unrelated to chest symptoms, smoking habits, initial erythrocyte sedimentation rate, or special features in the initial radiographs, so these did not provide any useful predictive characteristics. Those with an initial negative Mantoux (1 T.U.) showed significantly less progression than those with a positive Mantoux. The lack of benefit and the short- and long-term complications of chemotherapy (weight gain, reduction in ventilatory capacity, dyspepsia, and streptomycin toxicity) show that this treatment is contra-indicated in miners with early complicated pneumoconiosis without a positive sputum. That new shadows develop during chemotherapy adds to the evidence from other sources that tuberculosis is unlikely to be a major factor in the pathogenesis of complicated pneumoconiosis in this area. Mycobacterium peregrinum (Runyon group IV) was isolated in three cases.