An overview of hexabromocyclododecane (HBCDs) in environmental media with focus on their potential risk and management in China

Hexabromocyclododecanes (HBCDs) are the subject of recent interest and potential risk assessment particularly in China due to its ubiquitous existence in a variety of environmental media. This paper reviews the recent studies conducted on HBCDs in different environmental media (air, soil, water, river sediment, sewage sludge, biota and daily food) in China. At the same time, human health risks via food and occupational exposure of HBCDs in production plants, expanded polystyrene (EPS) and extruded polystyrene (XPS) plants were assessed. The review reveals that HBCDs levels of air, soil, sediment, sewage sludge, biota and food presented a geographical variation in the eastern coastal regions of China. There were many factors resulting in the variation, such as sampling sites, climate and analytical method. In terms of diastereoisomer, alpha-HBCD and gamma-HBCD were the predominant diastereoisomers in air, soil, sediment, and sewage sludge. In the water, alpha-HBCD and gamma-HBCD shared the major proportion to the total HBCDs. However, only alpha-HBCD was the predominant diastereoisomer in biota. With regard to human exposure pathway to HBCDs, food was the major route for human exposure to HBCDs, especially meat. In addition, soil and road dust were also important exposure pathways. Furthermore, workers and residents, especially infants in and around waste dumping sites and industrial areas are exposed to the highest HBCDs levels among all the populations studied thus far. HBCDs posed a potential threat to the environment and human health. Therefore, risk assessment and management have an important role to play in preventing and mitigating HBCDs risks. (C) 2018 Elsevier Ltd. All rights reserved.