Occurrence, accumulation and potential toxicity of parent and halogenated polycyclic aromatic hydrocarbons in pooled serum of people in different age groups from four Chinese cities

Halogenated polycyclic aromatic hydrocarbons (HPAHs) and polycyclic aromatic hydrocarbons (PAHs) were determined in human serum samples pooled by donor age (<20, 20–29, 30–39, 40–49 and ≥50 y). The pooled samples were collected from four Chinese cities, Yantai (Shandong Province), Ganzi (Sichuan Province), Huaihua (Hunan Province), and Lingshui (Hainan Province). The concentrations of HPAHs and PAHs were in the range of 4.26–633 ng/g lipid and 249–1642 ng/g lipid from the different cities. Although the levels of HPAHs in blood samples varied among the populations of the four cities, 1,5-dichloroanthracene (1,5-Cl 2 Ant) was the predominant contributor to HPAHs in the serum samples, accounting for over 85.7% of its total concentration. Furthermore, 1,5-Cl 2 Ant serum concentrations increased significantly with age. Notably, molecular docking results show that 1,5-Cl 2 Ant not only acquires the ability to bind d-AhR PAS-B domain, but also binds at the similar sites as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and benzo[a]pyrene (BaP), suggesting that 1,5-Cl 2 Ant, like TCDD and BaP, may cause a wide variety of toxicity via AhR-mediated signaling pathways. The bioaccumulation potential of 1,5-Cl 2 Ant in the human body and its associated toxicity observed in this study need special attention. • HPAHs and PAHs concentrations in human serum varied across four Chinese cities. • 1,5-Cl 2 Ant was the dominant HPAH, accounting for 85.7% of total HPAHs. • Molecular docking suggests 1,5-Cl 2 Ant may cause toxicity via AhR-mediated pathways. • 1,5-Cl 2 Ant serum levels increase with age, highlighting its potential for bioaccumulation.