Silicosis and silicotuberculosis amongst small scale gemstone miners in Northern Tanzania

在世界范围内，约有4600万人在“手工小规模矿山”(ASM)工作，这一数字远远超过大型采矿所雇用的700万人。ASM仅位于资源匮乏的国家，由当地所有，不受监管，使用人工开采方法--但它们总共生产高达全球四分之一的矿物和贵金属。尽管手工采矿可能是摆脱贫困的一条途径，但这类工作的风险很高，但几乎完全无法衡量。最近对ASM研究中的研究主题进行了审查，得出的结论是需要进行更多的研究，特别是对传染性疾病(如结核病)和呼吸系统疾病的研究。矽肺病是一种无法治愈的肺部疾病，由在硬岩采矿等活动中吸入结晶二氧化硅引起。它通常发展缓慢，但当二氧化硅水平非常高时，可能会更快地发病，出现早期呼吸衰竭和死亡。重要的是，矽肺使患肺结核的风险增加约四倍，矿工除了矽肺外，通常还会患上这种疾病。坦桑石是一种宝石，专门在坦桑尼亚北部的梅雷拉尼发现，使用ASM方法在深井中开采，大约有1万名工人，分布在大约100个矿山。他们对二氧化硅的暴露似乎非常高，而且有迹象表明，在工作年限不到5年的年轻矿工中，侵袭性矽肺的发病率非常高。同样，他们的结核病患病率很高，当地非采矿社区的人也是如此。有人担心，该地区控制结核病的努力因疾病在矿山内的传播以及矿工与当地接触者之间的传播而受到阻碍。我的目标是测量随着时间的推移，矽肺病和结核病在坦桑矿工中的发展和进展，并确定这些因素对他们的健康和谋生能力有多大影响。此外，我将研究结核病从矿工传播到当地社区是否普遍。为此，我提出了两项研究。在第一个阶段，我将从10到16个矿井中招募和跟踪410名矿工。在他们中，我将测量他们的肺功能和症状，并在研究开始时进行结核病测试和胸部X光检查(以检测矽肺)，然后在18个月后再次进行。在第二项研究中，我将使用全基因组测序(WGS)来识别患有这种疾病的矿工中的特定结核病菌株；我将对通过当地社区筛查计划发现患有结核病的个人使用同样的技术。WGS是一种技术，它允许读取有机体的整个遗传密码。这项工作将与坦桑尼亚国家结核病医院Kibong‘oto传染病医院的传染病小组合作完成，利用他们正在进行的结核病筛查计划和与当地ASM社区的密切关系。为了协助研究管理和增强影响力，我将召集一个利益相关者研究咨询委员会，成员包括我们在国家结核病和麻风病项目的合作者、专家学者、来自当地矿山和以前接受结核病治疗的组织的代表。这项新颖的工作涉及职业病和传染病之间的交叉，应该会产生对预防两者都很重要的研究结果-在一个日益具有全球重要性的领域。

Worldwide, some 46m people work in 'artisanal, small scale mines' (ASM), a number far larger than the 7m employed in large scale mining. ASMs are located exclusively in resource-poor countries, are locally owned, unregulated and use manual methods of extraction - but collectively produce up to a quarter of global minerals and precious metals. While artisanal mining may be a route out of poverty, the risks of such work are high, yet almost entirely unmeasured. A recent review of research topics in studies of ASM, concluded that more research was needed, particularly of infectious (such as tuberculosis) and respiratory diseases.Silicosis is an incurable lung disease caused by the inhalation of crystalline silica in activities such as hard rock mining. It generally develops slowly, but when levels of silica are very high there may be a far more rapid onset with early respiratory failure and death. Importantly, silicosis increases the risk of tuberculosis (TB) by about four-fold and miners often contract the disease in addition to silicosis. Tanzanite is a gemstone exclusively found in Mererani, northern Tanzania, and mined in deep shafts using ASM methods by around 10,000 workers, across about 100 mines. Their exposures to silica appear to be very high, and there is suggestive evidence of very high rates of aggressive silicosis in young miners with fewer than 5 years of employment. Similarly, their rates of TB are high, as are those in the local non-mining community. There is concern that efforts to control TB in the area are hampered by transmission of the disease within mines, and between miners and their local contacts.I aim to measure, across time, the development and progression of silicosis and TB in tanzanite miners and determine how much these have an impact on their health and their ability to earn a living. In addition, I will examine whether the spread of TB from miners to the local community is common.To do this I propose two studies. In the first, I will recruit and follow a group of 410 miners from a selection of 10-16 mines. In them, I will make measurements of their lung function and symptoms, and perform TB tests and chest x-rays (to detect silicosis) at the beginning of the study and then again after 18 months. In a second study, I will use 'whole genome sequencing' (WGS) to identify particular strains of TB in miners with the diseases; I will use the same technique in individuals discovered to have TB through a local community screening program. WGS is technique that that allows for entire genetic codes of an organism to be read. It will allow me to identify which strains of TB are present in the population while checking for resistance to treatments, and, crucially, to map transmission between individuals.This work will be done in collaboration with the infectious disease team at the Kibong'oto Infectious Diseases Hospital, the National TB hospital of Tanzania, taking advantage of their ongoing TB screening programme and close relationships with the local ASM community. To assist with study management and to enhance impact, I will convene a study Advisory Board of stakeholders including our collaborators at the National TB and Leprosy program, expert academics, and representatives from the local mines and from organisations for persons previously treated for TB.This novel work concerns the intersection between occupational and infectious diseases and should produce findings that will be of importance in the prevention of both - in a sector that is of growing, global importance.