National Heart and Lung Institute, Imperial College London, London, UK
National Heart and Lung Institute, Imperial College London, London, UK.
Thorax. 2024 Sep 18;79(10):934-942. doi: 10.1136/thorax-2024-221447.
Silicosis, a chronic respiratory disease caused by crystalline silica exposure, is a persistent global lung health issue. No systematic review of the relationship between cumulative respirable crystalline silica (RCS) exposure and silicosis exists. UK exposure limits are currently under review. We therefore performed a systematic review and dose-response meta-analysis of this relationship.
Web of Science, Medline and Embase were searched on 24 February 2023. Studies of radiographic, autopsy or death certificate silicosis, with an estimated average follow-up of over 20 years since first employment, were included. Cumulative silicosis risk methods were compared. The relative risks (RR) of silicosis at increasing cumulative exposures were calculated and used to estimate the absolute risk reduction (ARR).
Eight eligible studies, including 10 cohorts, contributed 8792 cases of silicosis among 65 977 participants. Substantial differences in cumulative risk estimates between methodologies exist. Using the same method, we observed higher cumulative silicosis risks among mining compared with non-mining cohorts. A reduction from 4 to 2 mg/m³-years in cumulative RCS exposure corresponded to substantial risk reductions among miners (RR 0.23 (95% CI 0.18 to 0.29, I=92.9%) with an ARR of 323 (95% CI 298 to 344) per 1000) and non-miners (RR 0.55 (95% CI 0.36 to 0.83, I=77.0%) with an ARR of 23 (95% CI 9 to 33) per 1000).
Despite significant heterogeneity, our findings support a reduction in permissible exposure limits from 0.1 mg/m to 0.05 mg/m³, particularly among mining populations. Further research is needed among non-miners as only two studies were eligible.
矽肺是一种由结晶二氧化硅暴露引起的慢性呼吸道疾病，是一个持续存在的全球肺部健康问题。目前尚无关于累积可呼吸结晶二氧化硅（RCS）暴露与矽肺之间关系的系统评价。英国的接触限值正在审查中。因此，我们对这种关系进行了系统评价和剂量-反应荟萃分析。
我们于 2023 年 2 月 24 日在 Web of Science、Medline 和 Embase 上进行了搜索。纳入了具有超过 20 年首次就业后平均随访时间的放射学、尸检或死亡证明矽肺的研究。比较了累积矽肺风险方法。计算了矽肺累积暴露增加时的相对风险（RR），并用于估计绝对风险降低（ARR）。
八项符合条件的研究，包括 10 项队列研究，共纳入了 65977 名参与者中的 8792 例矽肺病例。不同方法学之间的累积风险估计存在显著差异。使用相同的方法，我们观察到采矿与非采矿队列之间的累积矽肺风险更高。在矿工中，RCS 暴露的累积量从 4 至 2mg/m³-年减少对应着显著的风险降低（RR 0.23（95% CI 0.18 至 0.29，I=92.9%），ARR 为 323（95% CI 298 至 344）/1000）和非矿工（RR 0.55（95% CI 0.36 至 0.83，I=77.0%），ARR 为 23（95% CI 9 至 33）/1000）。
尽管存在显著的异质性，但我们的研究结果支持将可允许暴露限值从 0.1mg/m³降低至 0.05mg/m³，特别是在采矿人群中。需要在非矿工中进行进一步研究，因为只有两项研究符合条件。
