煤尘中游离二氧化硅在人体呼吸系统中的剂量及影响因素分析

Analysis of free silica dose in human respiratory system and the influencing factors of coal dust

游离二氧化硅(SiO_(2))是导致尘肺病的重要因素。为了研究煤尘中游离SiO_(2)在呼吸系统中的剂量,采用多路径粒子剂量测定模型测定煤尘粒子在呼吸系统中的沉积率,在此基础上以呼吸接触游离SiO_(2)剂量、质量分散度和沉积率三者乘积作为游离SiO_(2)在呼吸系统中的剂量,并对煤尘沉积的影响因素进行了分析。结果表明:1个工作日内游离SiO_(2)在胸外区沉积剂量最高,肺部其次;煤尘颗粒在呼吸系统中的沉积与粒径和劳动强度有关,与煤尘浓度无关;沉积率受粒径的影响相对较大,呼吸系统中煤尘沉积率曲线随粒径增大呈U形变化;沉积率受劳动强度的影响相对较小,劳动强度增强沉积率变化幅度增大。研究成果可以为尘肺病防控提供参考。

This study is to provide a new method for calculating free silica in the human respiratory system.The method can solve the difficult-to-measure effects of the distribution of dust in the body,the retention rate of dust in the respiratory tract,and the body’s clearance function.We went to the coal preparation plant to measure coal dust parameters on site.We calculated the free silica dose of respiratory exposure using the cumulative silica dust exposure method.We also calculated the coal dust deposition rate in the respiratory system using the multiple-path particle dosimetry(MPPD)model.We can input particle properties,airway morphology,exposure condition,and deposition clearance parameters into the model to get the coal dust deposition rate in the ET area,TB area,and P area.Finally,we calculated the free silica dose in the respiratory system that is the product of the free silica dose of respiratory exposure,quality dispersion of coal dust,and coal dust deposition rate.According to the calculation results,we analyzed the distribution of free silica dose in various parts of the respiratory system,the deposition rules,and deposition influencing factors of coal dust in the respiratory system.The results show that free silica dose of the chest area greater than the lungs in a working day,and 86%to 89%of free silica deposited in the respiratory system,while only 13%to 21%free silica deposited in the lungs.The deposition rate of coal dust is related to particle size and labor intensity but has nothing to do with coal dust concentration.The deposition rate is relatively greatly affected by the particle size,and the coal dust deposition rate curve in the respiratory system shows a“U”-shaped change with the increase of the particle size.The deposition rate is relatively less affected by the labor intensity,and the variation of the deposition rate increases with the increase of labor intensity.The research results can provide a reference for the prevention and control of pneumoconiosis.