瓷厂与锡矿及钨矿石英粉尘表面铝硅酸盐包裹的测定和分析

Determination and analysis of silica particles surface alumino-silicate occlusion

目的探讨石英粉尘表面铝硅酸盐包裹的测定方法和包裹对粉尘致病作用的影响。方法应用呼吸性粉尘采样器以2L/min采集江西钨矿、瓷厂和广西锡矿粉尘,用扫描电镜-能散X线分光计(SEM-EDS)以5keV和20keV电压照射测定呼吸性粉尘颗粒中各元素成分的含量,计算不同电子伏特照射下粉尘颗粒中硅与铝的比值。结果7个瓷厂、3个锡矿和3个钨矿的47个粉尘样本共计3982个粉尘颗粒,瓷厂样本的89%(24/27)与锡矿样本的27%(3/11)和钨矿样本的56%(5/9)存在明确的铝硅酸盐包裹,与对照样本比较,差异有统计学意义(P＜0．01)。瓷厂粉尘颗粒的45%、锡矿的18%和钨矿的13%存在表面铝硅酸盐包裹。瓷厂粉尘与钨矿和锡矿粉尘表面铝硅酸盐含量的差异有统计学意义(P＜0．01),高铝硅酸盐含量的粉尘颗粒在瓷厂、锡矿和钨矿样本中的比率分别为22%、7%和10%。结论瓷厂工作场所粉尘颗粒表面夹杂铝硅酸盐含量高于钨矿和锡矿的粉尘,粉尘颗粒表面成分的分析对解释不同厂矿尘肺发病的差异有一定作用。

Objective To investigate the methods of determining aluminum silicate coated on the surface of silica particles and analyze the role of surface occlusion on development of silicosis. Methods Respirable dust samples were collected on filters using 2 L/min flow in tungsten mines and pottery factories of Jiangxi province, and tin mines of Guanxi province. Dust particles were analyzed by a multiple-voltage scanning electron microscopy-energy dispersive X-my spectroscopy（MVSEM-EDS） using 20 KeV and 5 KeV electron beam accelerating voltages. Changes in the silicon to aluminum X-my line intensity ratio between the two voltages are compared particle by particle. This provided an index that distinguishes a silica particle that was homogeneously aluminum-contaminated from a clay coated silica particle. Results The total of 3 982 dust particles from 47 dust samples of seven pottery factoties, three fin mines and three tungsten mines were analyzed in this study. Significant difference of aluminum silicate coated on the surface of silica particle was shown between particles from pottery factories and fin mines. The average sample percentage of respirbale-sized silica particles alumino-silicate occlusion in the pottery factories（45% ） was higher than that in the tin mines（ 18% ） and tungsten mines（ 13% ）. Conclusion Higher percentages silica particles alumino-silicate occlusion is observed in the pottery factories than that in metal mines. These surface analysis results help to understand differences in risk of silicosis when exposure is normalized to cumulative respirable surface silica dust.