Chlorinated paraffins in plasma of healthy elderly adults: Method development, temporal variability, and exposure determinants

Ke Fang; Xiaojie Guo; Runming He; Yibin Sun; Yixuan Huang; Hongyang Cui; Yifu Lu; Wen Gu; Chao Wang; Yi Wan; Song Tang; Xiaoming Shi

doi:10.1016/j.jhazmat.2025.139065

Chlorinated paraffins in plasma of healthy elderly adults: Method development, temporal variability, and exposure determinants

J Hazard Mater. 2025 Jun 25:495:139065. doi: 10.1016/j.jhazmat.2025.139065. Online ahead of print.

Authors

Ke Fang¹, Xiaojie Guo², Runming He¹, Yibin Sun³, Yixuan Huang³, Hongyang Cui⁴, Yifu Lu⁵, Wen Gu¹, Chao Wang¹, Yi Wan³, Song Tang⁶, Xiaoming Shi⁷

Affiliations

¹ China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China.
² China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China; School of Public Health, Southern Medical University, Guangdong, Guangzhou 510515, China.
³ College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
⁴ School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
⁵ China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
⁶ China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 102206, China. Electronic address: tangsong@nieh.chinacdc.cn.
⁷ China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China; Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China; National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 102206, China. Electronic address: shixm@chinacdc.cn.

PMID: 40580735
DOI: 10.1016/j.jhazmat.2025.139065

Abstract

Chlorinated paraffins (CPs) are a group of persistent organic pollutants widely applied in industrial processes, raising significant concerns regarding human internal exposure through environmental and dietary pathways. Currently, there is a lack of effective and cost-efficient methods for extracting CPs from large-scale human biomonitoring samples, and short-term variations in human internal exposure remain insufficiently characterized, particularly among the vulnerable elderly population. Here a novel, rapid, and highly efficient pretreatment method was developed to simultaneously quantify CPs of varying carbon chain lengths in minimized volumes of human plasma. This method significantly reduced the required sample volume and streamlined operational steps. It also minimized matrix effects while maintaining high accuracy and precision, enabling the simultaneous extraction of 13 very-short-chain chlorinated paraffins (vSCCPs), 24 short-chain chlorinated paraffins (SCCPs), 34 medium-chain chlorinated paraffins (MCCPs), and 35 long-chain chlorinated paraffins (LCCPs) from limited plasma samples (50 μL). The method detection limits (MDLs) and method quantification limits (MQLs) ranged from 0.02 to 1.80 ng/mL and 0.06-7.21 ng/mL, respectively. Using this method, we assessed temporal variability in internal CPs exposure across 315 plasma samples collected over 5 consecutive months from 76 healthy elderly individuals (aged 60-69) in Jinan, China. The detection frequencies were highest for SCCPs (98.73 %) and vSCCPs (90.48 %), followed by MCCPs (31.75 %) and LCCPs (16.83 %). Mean plasma concentrations were 6.12 ng/mL for SCCPs, 0.91 ng/mL for vSCCPs, 0.33 ng/mL for MCCPs, and 0.04 ng/mL for LCCPs, with a declining trend observed for vSCCPs and SCCPs over time. Correlation analysis and linear mixed-effects models (LMM) suggested that diet was the primary exposure pathway for CPs, with indoor hygiene practices also showing associations. This study provides a significant methodological advancement for biomonitoring CPs exposures, offering a powerful tool for characterizing exposure dynamics and providing a groundwork for mitigating health risks associated with these persistent pollutants globally.

Keywords: Biological sample; Chlorinated paraffins; Influencing factor; Internal exposure; Pretreatment method.