目的调查了解郧县粉尘作业场所粉尘中游离二氧化硅(SiO2)的含量,为预防矽肺病提供基础资料。方法采集不同类型作业场所呼吸带粉尘,用焦磷酸质量法测定游离二氧化硅含量。结果游离SiO2<10%的有煤尘、大理石尘、石灰石尘、水泥尘、重晶石尘,10%≤游离SiO2≤50%的有砂轮尘、50%<游离SiO2≤80%的有铸造车间混合尘,≥80%的有铸造尘、石英砂;游离SiO2含量以石英砂尘为最高(91.1±3.4%),以重晶石为最低(3.4±0.4%),230份粉尘游离SiO2含量平均值为26.3%。结论作业场所中不同种类粉尘中游离二氧化硅含量差异较大,在进行粉尘浓度监测时,要根据游离二氧化硅的含量,才能确定是否超过职业接触限值。 Objective To investigate the content of free silica (SiO2) in the dust of Yun County dust workplace and provide basic information for the prevention of silicosis. Methods Respiratory dust was collected from different types of workplaces and the content of free silica was determined by pyrophosphoric acid method. Results Free SiO2 <10% coal dust, marble dust, lime dust, cement dust, barite dust, 10% ≤ free SiO2 ≤ 50% of the wheel dust, 50%