Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium.
Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium.
Sci Total Environ. 2014 May 1;479-480:267-76. doi: 10.1016/j.scitotenv.2014.01.083. Epub 2014 Feb 22.
The maximum cumulative ratio (MCR) method allows the categorisation of mixtures according to whether the mixture is of concern for toxicity and if so whether this is driven by one substance or multiple substances. The aim of the present study was to explore, by application of the MCR approach, whether health risks due to indoor air pollution are dominated by one substance or are due to concurrent exposure to various substances. Analysis was undertaken on monitoring data of four European indoor studies (giving five datasets), involving 1800 records of indoor air or personal exposure. Application of the MCR methodology requires knowledge of the concentrations of chemicals in a mixture together with health-based reference values for those chemicals. For this evaluation, single substance health-based reference values (RVs) were selected through a structured review process. The MCR analysis found high variability in the proportion of samples of concern for mixture toxicity. The fraction of samples in these groups of concern varied from 2% (Flemish schools) to 77% (EXPOLIS, Basel, indoor), the variation being due not only to the variation in indoor air contaminant levels across the studies but also to other factors such as differences in number and type of substances monitored, analytical performance, and choice of RVs. However, in 4 out of the 5 datasets, a considerable proportion of cases were found where a chemical-by-chemical approach failed to identify the need for the investigation of combined risk assessment. Although the MCR methodology applied in the current study provides no consideration of commonality of endpoints, it provides a tool for discrimination between those mixtures requiring further combined risk assessment and those for which a single-substance assessment is sufficient.
最大累积比（MCR）方法可根据混合物是否对毒性有影响以及是否由一种物质或多种物质引起毒性来对混合物进行分类。本研究的目的是通过应用 MCR 方法，探讨室内空气污染引起的健康风险是由一种物质主导还是由同时接触多种物质引起的。对四项欧洲室内研究（提供五个数据集）的监测数据进行了分析，共涉及 1800 份室内空气或个人暴露记录。MCR 方法的应用需要了解混合物中化学物质的浓度以及这些化学物质的基于健康的参考值。对于这种评估，通过结构化审查过程选择了单一物质基于健康的参考值（RV）。MCR 分析发现混合物毒性关注样本的比例存在很大差异。这些关注组中的样本比例从 2%（佛兰芒学校）到 77%（巴塞尔的 EXPOLIS，室内）不等，这种差异不仅是由于研究中室内空气污染物水平的变化，还由于其他因素，如监测物质的数量和类型、分析性能和 RV 的选择。然而，在 5 个数据集中的 4 个中，发现相当多的情况下，化学物质逐个评估未能确定需要进行联合风险评估的情况。尽管本研究中应用的 MCR 方法没有考虑终点的共同性，但它提供了一种工具，可用于区分需要进一步进行联合风险评估的混合物和仅需要进行单一物质评估的混合物。
