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

Abstract

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-Cl₂Ant) was the predominant contributor to HPAHs in the serum samples, accounting for over 85.7 % of its total concentration. Furthermore, 1,5-Cl₂Ant serum concentrations increased significantly with age. Notably, molecular docking results show that 1,5-Cl₂Ant 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-Cl₂Ant, like TCDD and BaP, may cause a wide variety of toxicity via AhR-mediated signaling pathways. The bioaccumulation potential of 1,5-Cl₂Ant in the human body and its associated toxicity observed in this study need special attention.