Silicosis and Silicotuberculosis Among Small Scale Gemstone Miners in Northern Tanzania

Artisanal, small-scale mining (ASM) is a large and essential component of the world's economy. Despite attendant risks, there is little research into risks to the health of artisanal miners. The tanzanite gemstone is mined exclusively in Northern Tanzania, in deep shafts using ASM techniques. There is concerning evidence that the burden of silicosis and tuberculosis (TB) amongst miners is high. In addition to miners' personal risks, there is concern that a high rate of silicotuberculosis may hamper community control of TB. Our primary aim is to measure the rate of silicosis progression among tanzanite miners. Our secondary aims include measuring the prevalence of TB among miners, describing TB transmission patterns in miners and the community, and assessing rates of 'catastrophic' economic loss amongst miners. To do this, the investigators propose two studies. First, the investigators will establish a prospective cohort of 410 small scale tanzanite miners and record symptoms, respiratory function including spirometry, chest radiography, and prevalence of TB and Human Immunodeficiency Virus (HIV) infection over an 18-month period. Second, the investigators will utilize an ongoing community-based TB screening program to perform a cross-sectional survey of TB prevalence among miners and community members. To assess TB transmission, the investigators will collect epidemiological data and perform whole genome sequencing (WGS) on positive Mycobacterium tuberculosis (MTb) culture samples. Given the lack of research and large global ASM workforce, 1 million of whom are in Tanzania, the results of this study will assist in the development and introduction of interventions to reduce the risks to respiratory health of artisanal mining in Tanzania and elsewhere; and provide ample scope for future work.