Chlorinated paraffins (CPs) are now attracting special concerns worldwide as one type of new persistent toxic substances as classified by the Stockholm Convention. CPs are extensively applied in household goods and indoor decoration materials, but information on their occurrence and exposure risk in such environments is still very scarce. In this study, the current concentrations, particle size distributions, and inhalation exposure characteristics and risk of CPs were investigated in regard to indoor air particulate matter. Both short chain (SCCPs) and medium chain CPs (MCCPs) were determined in all size-fractioned particle samples with a range of 6.20–17.8 and 5.98–40.5 ng m⁻³, respectively. MCCPs were more abundant than SCCPs. Size distributions revealed that individual homologs, SCCPs, and MCCPs exhibited a similar unimodal distribution peaking in the fine particles with a diameter of 0.56–1.0 μm. The relative abundance of longer-chain or more heavily chlorinated homologs tend to gradually increase with particle size shift from coarse to fine mode. Vapor pressure may be a critical factor governing the size-dependent distribution of CPs. Deposition of particulate CPs in the human respiratory tract is also size-dependent. The contributions of fine particles to the regional depositions of CPs in the human respiratory tract increase with increasing carbon chain length or chlorine content. Based on the size-dependent distributions of CPs, inhalation exposure assessment from the ICRP model indicated no significant health risk due to CPs in current indoor environments.

作为《斯德哥尔摩公约》所分类的一种新型持久性有毒物质，氯化石蜡（CPs）现在在世界范围内引起了特殊关注。CPs广泛应用于家庭用品和室内装饰材料中，但是在此类环境中它们的出现和暴露风险的信息仍然非常匮乏。在这项研究中，针对室内空气颗粒物，研究了当前的浓度，粒径分布，吸入暴露特性和CPs的风险。所有尺寸分级的颗粒样品中的短链（SCCP）和中链CP（MCCP）均在6.20–17.8和5.98–40.5 ng m ^-3的范围内测定， 分别。MCCP比SCCP更为丰富。大小分布表明，单个同系物，短链氯化石蜡和多氯联苯CPs在直径为0.56-1.0μm的细颗粒中表现出相似的单峰分布峰。长链或重度氯化的同系物的相对丰度往往随着粒度从粗模式到细模式的变化而逐渐增加。蒸气压可能是控制CP尺寸依赖性分布的关键因素。人呼吸道中颗粒状CP的沉积也取决于大小。随着碳链长度或氯含量的增加，细颗粒对CPs在人呼吸道中的区域沉积的贡献也增加。根据CP的大小相关分布，