Tuberculosis among workers exposed to free silica dust

Tuberculosis (TB) is a global emergency. Poverty, increasing migration, homelessness and the compulsions to live and work in high-risk environments are making people increasingly susceptible to the disease. Those working in mines, construction work, stone-crushing and in other similar occupations where there is a greater level of exposure to silica dust are specially vulnerable. Though the association between TB and silicosis has been firmly established by the results of epidemiologic studies no attempts have been made to study the epidemiological features of radiologically active TB among free silica exposed workers. Thus the cross sectional study was carried out among slate pencil workers and quartz stone crushers to assess the prevalence of TB and some associated epidemiological factors. It included 253 quartz workers and 102 slate pencil workers. Clinical history and chest radiographs were used for labeling the subjects as tuberculotic. The pulmonary functions of the subjects were measured using Spirovit SP- 10. Statistical analysis was carried out using statistical software package Epi Info 3.3.2. Among stone crushers the prevalence of TB was found to be 10.7% while among slate pencil workers it was as high as 22.5%. Among the quartz stone-crushers the workers aged ≥35 years, those exposed for ≥3 years and those who were smokers had higher risk TB while among the slate pencil workers, only those exposed for ≥10 years had higher risk. Though the FVC and FEV(1) values of the workers having TB were lower than those having normal radiographs, the differences were found to statistically non-significant.