Prevalence and determinants of evidence of silicosis and impaired lung function, among small scale tanzanite miners and the peri-mining community in northern Tanzania

Among mining communities in Tanzania, the limited data available suggests the prevalence of silicosis, obstructive lung diseases (OLD) and restrictive lung disease (RLD) to be around 1.6%, 1.9% and 8.8% respectively. Our study therefore aimed to determine the prevalence and factors associated with evidence of silicosis and ILF among tanzanite mining community in northern Tanzania. We conducted a cross-sectional study, involving 330 randomly selected miners and 330 conveniently selected non-mine workers from the peri-mining community (PMC) in Mererani mines, northern Tanzania. Evidence of silicosis was defined based on study participants’ history of exposure to mining dust and digital chest radiological findings with reference to the 2011 ILO classification of pneumoconiosis. Impaired lung function was determined by spirometry using American Thoracic Society (ATS)/European Respiratory Society (ERS) recommended system 3. Association between evidence of silicosis/impaired lung function and presumed risk factors were determined using binary logistic regression analyses. The study found that 99/330 (30.0%) of miners had evidence of silicosis, of whom 97.0% had accelerated silicosis. Among miners and community members, 75 (11.4%) had ILF, of whom 30 (4.5%) had COPD, 9 (1.4%) had asthma, 29 (4.4%) had restrictive lung disease and 7 (1.1%) had mixed pattern of both obstructive and restrictive lung disease. We found that having a daily income of more than USD 4.3 was associated with lower odds of silicosis (aOR 0.57, 95% CI 0.37-0.89, p<0.05) while ILF was associated with being a miner (aOR 2.06, CI=1.38-3.07, p<0.001). We found a concerningly high prevalence of evidence of silicosis despite short durations of exposure among small scale tanzanite miners. Immediate dust control measures including deployment of wet drilling, wearing of personal protective equipment (PPE) and regular monitoring of dust exposure need to be enforced by the OSHA (Tanzania). ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Funds to accomplish this research work was obtain from the DAAD German Academic Exchange Service LHL International (Norway). The DAAD grant number 91672520, url: https://www.daad.de/en/. The funds from LHLI, was not a grant, rather was obtained through partnership agreement with Kibong’oto Infectious Diseases Hospital (2021), in which among other things, was to support addressing lung health among mine workers, url: https://www.lhl.no/en/lhl-international/. In both funds, the authors who received the funds was AWM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical clearance was obtained from the Kilimanjaro Christian Medical University College (KCMUCo) No. 2416 and the Medical Research Coordinating Committee of the National Institute for Medical Research (NIMR) No: NIMR/HQ/R.8a/Vol.IX/3308. Permission to conduct the study was sought from the Permanent Secretary – Presidents’ Office, Regional Administration & Local Government (PS-PORALG), and the owners/managers for the specific mining pits. Written informed consent, translated in Kiswahili language was obtained from each study participant. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data have been provided as part of the submitted article