From headwaters to estuary: Distribution and fate of halogenated flame retardants (HFRs) in a river basin near the largest HFR manufacturing base in China

Abstract

With the gradual phasing out of polybrominated diphenyl ethers (PBDEs), market demands for alternative halogenated flame retardants (HFRs) are increasing. The Laizhou Bay area is the biggest manufacturing base for brominated flame retardants (BFRs) in China, and the Xiaoqing River is the largest and most heavily contaminated river in this region. Water and sediment samples were collected from the headwaters to the estuary of the Xiaoqing River to investigate the distribution and fate of HFRs [i.e., PBDEs, alternative brominated flame retardants (aBFRs) and dechlorane plus (DPs). In the water samples, DPs was the most abundant flame retardant (median: 11.7ng/L), followed by decabromodiphenylethane (DBDPE) (5.92ng/L). In the sediment samples, DBDPE was the predominant flame retardant (39.5ng/g dw), followed by decabromodiphenyl ether (BDE 209) (2.81ng/g dw). The levels of DBDPE exceeded those of BDE 209 in most samples, indicating the overwhelming replacement of BDE 209 by DBDPE in this area. In the river section of this study, point source and atmospheric deposition followed by land runoff were the major factors influencing the distribution of HFRs, whereas in the estuary, riverine discharge, the estuarine maximum turbidity zone (MTZ), and hydrodynamic parameters played more important roles. Manufacturing is a significant source of contamination of the Xiaoqing River basin through atmospheric deposition and wastewater discharge.

Halogenated flame retardants in the sediments of the Chinese Yellow Sea and East China Sea

“…The PBDE concentrations reported in this study were comparable to those in sediments from four bays in Northern China (Zhen et al, 2016), Yangtze River Delta, East China (Zhu et al, 2013), and Western Arctic Ocean (Cai et al, 2012). This study reported values much lower than the Xiaoqing River in China (Zhen et al, 2018), three bays in South America (Baron et al, 2013), and Llobregat river, Spain (Baron et al, 2014). For aBFRs, the levels in this study were higher than those found in Yangtze River Delta, East China (Zhu et al, 2013), three bays in South America (Baron et al, 2013), and Western Arctic Ocean (Cai et al, 2012), but lower than those in four bays in North China (Zhen et al, 2016), Llobregat river, Spain (Baron et al, 2014), and Xiaoqing River, China (Zhen et al, 2018).…”

“…This study reported values much lower than the Xiaoqing River in China (Zhen et al, 2018), three bays in South America (Baron et al, 2013), and Llobregat river, Spain (Baron et al, 2014). For aBFRs, the levels in this study were higher than those found in Yangtze River Delta, East China (Zhu et al, 2013), three bays in South America (Baron et al, 2013), and Western Arctic Ocean (Cai et al, 2012), but lower than those in four bays in North China (Zhen et al, 2016), Llobregat river, Spain (Baron et al, 2014), and Xiaoqing River, China (Zhen et al, 2018). These results indicated a relatively moderate level of contamination at the sites studied herein.…”

“…Most HFRs have been widely detected in the atmosphere (Cetin and Odabasi, 2008) (Melymuk et al, 2012), seawater (Moeller et al, 2011), sediments (Chen et al, 2013), and other environmental media, as well as in humans (Mitchell et al, 2012;Zhao et al, 2008). Because of their high octanol-water partition coefficient (Kow) and hydrophobicity, HFRs are readily adsorbed on particles and become enriched in sediments in coastal regions (Zhen et al, 2018). Marine sediments are considered as major environmental sinks of HFRs.…”

From headwaters to estuary: distribution, sources, and ecological risk of polycyclic aromatic hydrocarbons in an intensively human-impacted river, China

“…To study the distribution and contamination of PAHs in the Xiaoqing River, sediment and water samples were collected from 30 sites in April, 2014. Details of the sampling strategy and stations can be found in previous publications (Jiang et al 2017) (Zhen et al 2018). Here, we provide a brief introduction.…”

Fates and ecological effects of current-use pesticides (CUPs) in a typical river-estuarine system of Laizhou Bay, North China

“…For example, a chemical plant, Shandong Tiancheng Biotechnology Co., Ltd., with an annual production of 15,000 tonnes of chlorpyrifos, is located at Zibo. Our previous studies have shown that the Xiaoqing River is seriously polluted by certain emerging contaminants, such as perfluoroalkyl carboxylic acids and brominated flame retardants (Heydebreck et al, 2015;Zhen et al, 2018b). However, little is known about the situation concerning CUPs in this area, especially in the Xiaoqing River; this is an important issue because CUPs are widely applied in this region.…”