Prevalence o f Pulmonary Tuberculosis in Graphite Miners by

Pulmonary tuberculosis is relatively frequent in workers exposed to silica or a mixed dust containing silica (Marchand, 1972). This increased susceptibility has been shown in relation to silica itself (Hunter, i962),coal (Rivers, James, Davies & Thompson, 1957) and talc (Siegal, Smith & Grecnburg, 1943). Since graphite too contains a proportion of silica which is about 2 % in the purest commercial product, one may expect to find an increased frequency of tuberculosis among graphite miners. There are few references in the literature on the association of tuberculosis and exposure to graphite dust. Hirsch, Kaas, Schaefer & Denst (1959) described a case of graphite pneumoconiosis where Battey type of non-tuber­ culous mycobacteria was isolated. Uragoda (19720) described 3 cases of pulmonary tuber­ culosis in graphite miners. Uragoda (19726) also reported a case of graphite pneumoconiosis winch was subsequently complicated by tuberculosis. However, there has been no report on the incidence or prevalence of tuberculosis in graphite miners.