背景:尽管意识不断提高,二氧化硅粉尘诱发的矽肺病仍然是中国巨大的疾病负担。令人担忧的是,目前,中国非煤矿山的硅尘暴露水平和矽肺风险尚不清楚。
目的:我们旨在确定近期硅尘暴露水平,并评估中国非煤矿山矽肺病的风险。
方法:在2020年5月至12月之间,我们对3个非煤矿山和1个公立医院进行了回顾性队列研究,使用多变量Cox回归分析,矽肺病累积危害比(H)和发病率(I)的预测公式,以及对中国10个省的155个非煤矿山的横断面研究,以确定硅尘暴露(PDE)的患病率,游离二氧化硅含量,以及总粉尘和可吸入粉尘浓度。采用国际矿业和金属委员会风险等级表和职业危害风险指数对矽肺的定性风险进行评估;采用预测公式对定量风险进行评估。
结果:Kaplan-Meier生存分析显示,暴露于二氧化硅粉尘的男性和女性矿工的矽肺概率存在显著差异(对数秩检验χ21=7.52,P=.01)。共有126处非煤矿山,有29,835名矿工和4623个灰尘样本,包括在内;13037名(43.7%)矿工暴露于二氧化硅粉尘,其中12,952(99.3%)为男性。中位数PDE,游离二氧化硅含量,总粉尘浓度,可吸入粉尘浓度为61.6%,27.6%,分别为1.30mg/m3和0.58mg/m3,表明非金属矿工,有色金属,小,露天矿遭受严重的硅尘暴露。综合定性风险评估显示,非煤矿工人患矽肺病的风险中等,硅尘和可吸入硅尘暴露所造成的风险高,中等,分别。当预测未来10年、20年和30年的H和I时,我们假设矿工的性别是男性。在暴露于当前总二氧化硅粉尘浓度的情况下,I10、I20和I30的中位数为6.8%,25.1%,49.9%,分别。在暴露于当前可吸入二氧化硅粉尘浓度的情况下,I10、I20和I30的中位数为6.8%,27.7%,57.4%,分别。这些发现表明,非金属矿,有色金属,小,露天矿具有较高的I和较高的定性矽肺风险。
结论:中国非煤矿工人,尤其是那些非金属的,有色金属,小,和露天矿,仍然遭受高水平的硅尘暴露和中等水平的矽肺风险。硅尘和可吸入硅尘的数据对于职业健康风险评估至关重要,以制定有效的控制措施来降低非煤矿山硅尘的含量。改善矿工的工作环境,并降低矽肺病的风险。
BACKGROUND: Despite increasing awareness, silica dust-induced silicosis still contributes to the huge disease burden in China. Worryingly, recent silica dust exposure levels and silicosis risk in Chinese noncoal mines remain unclear.
OBJECTIVE: We aimed to determine recent silica dust exposure levels and assess the risk of silicosis in Chinese noncoal mines.
METHODS: Between May and December 2020, we conducted a retrospective cohort study on 3 noncoal mines and 1 public hospital to establish, using multivariable Cox regression analyses, prediction formulas of the silicosis cumulative hazard ratio (H) and incidence (I) and a cross-sectional study on 155 noncoal mines in 10 Chinese provinces to determine the prevalence of silica dust exposure (PDE), free silica content, and total dust and respirable dust concentrations. The qualitative risk of silicosis was assessed using the International Mining and Metals Commission\'s risk-rating table and the occupational hazard risk index; the quantitative risk was assessed using prediction formulas.
RESULTS: Kaplan-Meier survival analysis revealed significant differences in the silicosis probability between silica dust-exposed male and female miners (log-rank test χ21=7.52, P=.01). A total of 126 noncoal mines, with 29,835 miners and 4623 dust samples, were included; 13,037 (43.7%) miners were exposed to silica dust, of which 12,952 (99.3%) were male. The median PDE, free silica content, total dust concentration, and respirable dust concentration were 61.6%, 27.6%, 1.30 mg/m3, and 0.58 mg/m3, respectively, indicating that miners in nonmetal, nonferrous metal, small, and open-pit mines suffer high-level exposure to silica dust. Comprehensive qualitative risk assessment showed noncoal miners had a medium risk of silicosis, and the risks caused by total silica dust and respirable silica dust exposure were high and medium, respectively. When predicting H and I over the next 10, 20, and 30 years, we assumed that the miner gender was male. Under exposure to current total silica dust concentrations, median I10, I20, and I30 would be 6.8%, 25.1%, and 49.9%, respectively. Under exposure to current respirable silica dust concentrations, median I10, I20, and I30 would be 6.8%, 27.7%, and 57.4%, respectively. These findings showed that miners in nonmetal, nonferrous metal, small, and open-pit mines have a higher I and higher qualitative silicosis risk.
CONCLUSIONS: Chinese noncoal miners, especially those in nonmetal, nonferrous metal, small, and open-pit mines, still suffer high-level exposure to silica dust and a medium-level risk of silicosis. Data of both total silica dust and respirable silica dust are vital for occupational health risk assessment in order to devise effective control measures to reduce noncoal mine silica dust levels, improve miners\' working environment, and reduce the risk of silicosis.