Woźniak H, Wiecek E, Bielichowska-Cybula G
Zakładu Aerozoli, Instytutu Medycyny Pracy, Lodzi.
Med Pr. 1996;47(2):151-7.
Exposure to dust mixture containing at the same time respirable mineral fibres and free crystalline silica may occur in Poland in mines and in the Lower Silesia plants processing mineral raw materials as well as in all plants which use asbestos products and MMMF. Workposts where thermal insulation is exchange with possible phase transformations during operations under conditions of high temperature, expose particularly complex problems. In the work environment of this kind, dust concentration of free crystalline silica becomes important but not sufficient criterion for evaluating working conditions and it may be misleading. A range of studies indispensable for the proper evaluation of exposure to dust, covering together with measurement of dust and SiO2 concentrations, determination of the mineral composition of dust, was developed. It was also found that the acceptable level of risk for neoplastic disease, namely 10(-3) can be attained in the work environment only if the concentration ranges from 0.05 to 0.1 f/cm3, that is equal to 20% of MAC value which is now binding in Poland. Cancer risk (lung cancer and mesothelioma jointly) during a 20-year exposure to concentrations equal to present MAC values should be estimated as about 10(-2) what indicates that risk is too high and it is necessary to diminish MAC values for asbestos dust.
在波兰，矿山、下西里西亚地区加工矿物原料的工厂以及所有使用石棉产品和人造矿物矿物纤维的工厂中，可能会出现同时接触可吸入矿物纤维和游离结晶二氧化硅的粉尘混合物的情况。在高温条件下作业时，热绝缘可能会发生相变的工作岗位，会出现特别复杂的问题。在这类工作环境中，游离结晶二氧化硅的粉尘浓度成为评估工作条件的重要但不充分的标准，且可能会产生误导。为了正确评估粉尘接触情况，开展了一系列必不可少的研究，这些研究除了测量粉尘和二氧化硅浓度外，还包括测定粉尘的矿物成分。还发现，只有当浓度范围为0.05至0.1 f/cm³时，即在波兰目前具有约束力的最高容许浓度（MAC）值的20%时，才能在工作环境中达到肿瘤疾病的可接受风险水平，即10⁻³ 。在20年接触等于目前MAC值的浓度期间，癌症风险（肺癌和间皮瘤合计）应估计约为10⁻² ，这表明风险过高，有必要降低石棉粉尘的MAC值。
