摘要
[目的 ]探讨生产场所矽尘环境瞬时浓度 (EIC)与其时间加权平均浓度 (TWA)间的关系。 [方法 ]在铸造厂、耐火材料厂和锡矿同时测定矽尘EIC和TWA。提出理想瞬时浓度的概念 ,基于理想瞬时浓度及其取值集合S的共同框架来分析EIC与TWA两者的关系 ,推导出TWA理论 =μeσ2 / 2 。以该公式将上述 3家厂矿EIC换算为理论TWA ,并与相应TWA实测值比较。 [结果 ]理论与实测TWA间的差别在耐火材料厂和锡矿均无显著性 (t =1.961和t =1.746,均P >0 0 5 ) ,该公式成立 ,而在铸造厂则否 (t=7.772 ,P <0 .0 5 )。 [结论 ]生产性矽尘EIC与TWA之间在多数情况下存在一定的函数关系 ,经TWA理论 =μeσ2 / 2可将EIC转换为TWA ,这对于我国制订粉尘职业接触限值时确定其TWA限值 。
Objective To study the relationship between the environmental instantaneous concentration(EIC) and time weighted average concentration(TWA) of silica dust in workplaces.[Methods] In a foundry,a factory producing fire-resistant materials and a tin mine,the dust levels in workplances were determined both in EIC and TWA simultaneously. A concept of so-called optimum instantaneous concentration was proposed as a basis to analyze the relationship between EIC and TWA,whereby a formula TWA theor=μe σ 2/2 deduced. By using this formula,measurements of EIC in all the workplaces were converted into theoretical TWA values,which were then compared with the actual values of determined TWA.[Results] There was no significant difference between results(Student t test,P>0.05) obtained from the fire-resistant materials factory and tin mine. But it was not the case for the foundry. [Conclusion] There exists a relationship expressed as TWA theor=μe σ 2/2,between EIC and TWA in most workplaces,which may be helpful in converting EIC into TWA concentrations and in setting the TWA value while working out a dust occupational exposure limit in China and also determining how much should be allowable for TWA excursion limit internationally.
出处
《环境与职业医学》
CAS
北大核心
2004年第4期254-257,共4页
Journal of Environmental and Occupational Medicine
基金
国家劳动卫生标准项目 (编号 :3 - 99- 751 )
关键词
矽尘
时间加权平均浓度
职业接触限值
关系
生产场所
粉尘
同时测定
公式
集合
结论
silica dust
environmental instantaneous concentration
time weighted average concentration
optimum instantaneous concentration
