目的:水泥属于最常用的建筑材料。熟料是水泥的主要成分,并且认为熟料矿物水化后pH的强烈增加是水泥生产工人肺功能下降的原因。有关水泥生产行业工作场所熟料暴露的信息很少。这项研究的目的是确定胸腔粉尘的化学成分,并量化水泥生产中工作场所对熟料的暴露。
方法:在位于8个不同国家的15家工厂的工作场所收集的1250个个人胸部样本的元素组成(爱沙尼亚,希腊,意大利,挪威,瑞典,瑞士,西班牙,土耳其)通过电感耦合等离子体发射光谱法(ICP-OES)测定,分别用于水溶性和酸溶性部分。正矩阵分解(PMF)用于确定不同来源对粉尘成分的贡献,并量化1227个胸部样品中的熟料含量。此外,分析了107个材料样品,以促进对PMF获得的因素的解释。
结果:各个植物的胸部质量浓度中位数在0.28至3.5mg/m3之间变化。具有8个水溶性和10个不溶性的PMF(即,酸溶性)元素浓度产生了五因素溶液:Ca,K,硫酸钠;硅酸盐;不溶性熟料;富含可溶性熟料;和富含可溶性钙。样品的熟料含量计算为不溶性熟料和富含可溶性熟料的因子的总和。所有样品的熟料分数中位数为45%(范围0-95%),对于单个植物,在20%至70%之间变化。
结论:根据文献中推荐的几个数学参数以及因素的矿物学可解释性,选择了PMF的5因素解决方案。此外,对这些因素的解释得到了测得的Al的表观溶解度的支持,K,Si,Fe,材料样品中的Ca含量较低。本研究中获得的总熟料含量大大低于基于样品中Ca浓度的估计值,并且略低于基于用甲醇/马来酸混合物选择性浸出后的Si浓度的估计值。在最近的一项电子显微镜研究中,还估计了目前调查的一家工厂的工作场所粉尘中的熟料丰度,两项研究之间的良好一致性为PMF的结果提供了信心。
结论:个人胸部样品中的熟料分数可以通过正矩阵分解从化学组成中定量。我们的结果可以对水泥生产行业的健康影响进行进一步的流行病学分析。由于这些估计对熟料暴露比气溶胶质量更准确,如果熟料是这些影响的主要原因,则预计与呼吸影响有更强的关联。
Cement belongs to the most used building materials. Clinker is the major constituent of cement, and it is believed that the strong increase of pH after hydration of clinker minerals is responsible for the observed decline in lung function of cement production workers. Information on clinker exposure at workplaces in the cement production industry is scarse. The aims of this study are to determine the chemical composition of thoracic dust and to quantify workplace exposure to clinker in cement production.
The elemental composition of 1250 personal thoracic samples collected at workplaces in 15 plants located in 8 different countries (Estonia, Greece, Italy, Norway, Sweden, Switzerland, Spain, Turkey) was determined by inductively coupled plasma optical emission spectrometry (ICP-OES), separately for water- and acid-soluble fraction. Positive matrix factorization (PMF) was used to determine the contribution of different sources to the dust composition and to quantify the clinker content in 1227 of the thoracic samples. In addition, 107 material samples were analysed to facilitate interpretation of the factors obtained by PMF.
The median thoracic mass concentrations varied for individual plants between 0.28 and 3.5 mg/m3. PMF with 8 water-soluble and 10 insoluble (i.e., acid-soluble) element concentrations yielded a five-factor solution: Ca, K, Na sulfates; silicates; insoluble clinker; soluble clinker-rich; and soluble Ca-rich. The clinker content of the samples was calculated as sum of the insoluble clinker and soluble clinker-rich factors. The median clinker fraction of all samples was 45% (range 0-95%), and varied between 20% and 70% for individual plants.
The 5-factor solution of PMF was selected on the basis of several mathematical parameters recommended in the literature as well as the mineralogical interpretability of the factors. In addition, interpretation of the factors was supported by the measured apparent solubility of Al, K, Si, Fe, and to a lesser extent Ca in material samples. The total clinker content obtained in the present study is considerably lower than estimates based on the Ca concentrations in a sample, and somewhat lower than estimates based on Si concentrations after selective leaching with a methanol/maleic acid mixture. The clinker abundance in workplace dust of one plant investigated in the present contribution was also estimated in a recent study by electron microscopy, and the good agreement between both studies gives confidence in the results of PMF.
The clinker fraction in personal thoracic samples could be quantified from the chemical composition by positive matrix factorization. Our results allow for further epidemiological analyses of health effects in the cement production industry. As these estimates are more accurate for clinker exposure than aerosol mass, stronger associations with respiratory effects are expected if clinker is the main cause of these effects.