Laboratory for Mineral Deposits Research, Department of Geology, University of Maryland, College Park, Maryland.
Chemistry & Industrial Hygiene, Inc., Wheat Ridge, Colorado.
J Appl Toxicol. 2020 Apr;40(4):515-524. doi: 10.1002/jat.3923. Epub 2020 Feb 10.
Amphiboles are common rock-forming minerals but when they form asbestos, they are known carcinogens. Mesothelioma mortality among miners and millers per the unit of asbestiform amphibole exposure varies significantly across cohorts when asbestos exposure measurements are based on the membrane filter method. Because the cohorts were exposed to different occurrences of asbestiform amphibole, variance in mesothelioma potency (R ) among cohorts is likely due to differences in exposure characteristics not reflected by the membrane filter method. In this paper using both linear and nonlinear models we correlate R from four mining and milling cohorts with two-dimensional parameters of the exposure. The parameters are based on the proportion of elongated minerals that are >5 μm in length from each occurrence that also have either (a) width ≤ 0.15 μm, or (b) width ≤ 0.25 μm. Based on the models we derived, it was possible to quantify R for the occurrences of asbestiform amphibole associated with mesothelioma excess but for which epidemiologically based R has not been published. It was demonstrated that modeled R for amphibole occurrences in nonasbestiform habits are lower (fibrous glaucophane) or not significant (cleavage fragments). The results of the study can be used in a risk assessment of elongated mineral particles and have implications for public policy and regulations.
角闪石是常见的造岩矿物，但当它们形成石棉时，就被称为致癌物质。根据膜滤法进行石棉暴露测量时，矿工和磨坊工人的石棉状角闪石暴露单位的间皮瘤死亡率在队列之间差异显著。由于这些队列接触到不同的石棉状角闪石，因此间皮瘤效力（R）的差异可能是由于暴露特征的差异所致，而膜滤法并未反映这些差异。在本文中，我们使用线性和非线性模型，将来自四个采矿和轧钢厂的 R 值与暴露的二维参数相关联。这些参数基于每个发生的长度>5 μm 的伸长矿物的比例，这些矿物也具有（a）宽度≤0.15 μm，或（b）宽度≤0.25 μm。根据我们推导出的模型，有可能量化与间皮瘤过量相关的石棉状角闪石发生的 R 值，但尚未发表基于流行病学的 R 值。结果表明，非石棉状习性中的角闪石发生的模型 R 值较低（纤维蓝闪石）或不显著（解理碎片）。该研究的结果可用于对伸长矿物颗粒进行风险评估，并对公共政策和法规产生影响。
