{
  "abstract": "Introduction High silicosis prevalence has been reported among 50 million small-scale miners globally. We aimed to assess the association of silicosis with cumulative silica exposure in current and ex-small-scale Tanzanite miners and allied workers.Methods All miners attending a screening event (11th-24th March 2024), including a nested random stratified sample of 23 mines, completed a questionnaire and chest Xray (CXR) and were offered testing for TB and HIV. CXRs were read by a blinded, experienced and trained International Labour Organisation (ILO) Classification reader; ≥ 1/0 profusion or large opacities defined silicosis. Previously published exposure measurements were used to assign job titles to high and low silica dust roles. Cumulative silica exposures were then estimated based on duration of current and previous job roles. Inverse probability weights were used to adjust for selection bias. Univariable logistic regression with cumulative silica exposure included as a restricted cubic spline was used to model the risk of silicosis. A sensitivity analysis assess the effect of reported water suppression on silicosis risk.Results Of 1291 current miners, ex-miners and persons who pan mine tailings, 1239 (96%) had reportable CXRs. The unweighted silicosis prevalence among current miners was 126/1083, 11.6% (95% CI 9.7%, 13.5%); weighted prevalence was 13.4% (95% CI 11.1%, 16.0%). Silicosis prevalence among ex-miners was 31/86, (36.0%, 95% CI 25.9%, 46.2%) and among persons who pan mine tailings was 6/77 (7.8%, 95% CI 2.9%, 16.2%). Among all groups, silicosis and more advanced disease were associated with duration and cumulative respirable silica exposure. Among miners and ex-miners with ≥ 20 years work, silicosis prevalence was 62/206 (30%) and 16/20 (80%), respectively. Among current miners, reported use of any water suppression appeared protective when compared to never water suppression, particularly at higher ranges of cumulative silica exposures ( figure 1).Abstract S113 Figure 1Predicted probability of ILO ≥ 1/0 silicosis, according to cumulative silica exposure in groups reporting different levels of water suppression (n = 1083)Conclusion Silicosis prevalence was high among current and ex-miners and was associated with cumulative silica exposures. Silicosis was also observed among workers panning mine tailings. The application of any water appears protective against silicosis. Possible sources of bias include job role and diagnosis misclassification and selection bias.",
  "authors": [
    {
      "affiliations": [
        "Imperial College London, London, UK"
      ],
      "name": "P Howlett"
    },
    {
      "affiliations": [
        "Kibongoto Infectious Diseases Hospital, Kilimanjaro, Tanzania"
      ],
      "name": "B Said"
    },
    {
      "affiliations": [
        "Kibongoto Infectious Diseases Hospital, Kilimanjaro, Tanzania"
      ],
      "name": "E Mwanga"
    },
    {
      "affiliations": [
        "Imperial College London, London, UK"
      ],
      "name": "OM Kon"
    },
    {
      "affiliations": [
        "Imperial College London, London, UK"
      ],
      "name": "A Amaral"
    },
    {
      "affiliations": [
        "Kibongoto Infectious Diseases Hospital, Kilimanjaro, Tanzania"
      ],
      "name": "S Mpagama"
    },
    {
      "affiliations": [
        "Imperial College London, London, UK"
      ],
      "name": "J Feary"
    }
  ],
  "title": "S113 Silicosis prevalence and association with cumulative silica exposure among current and ex- underground small-scale miners in Northern Tanzania",
  "uid": "9663b29e-a0ab-5c11-8b72-5cf0fc5935d1"
}