Hexabromocyclododecane diastereoisomers in surface sediments from river drainage basins of Shanghai, China: occurrence, distribution, and mass inventory

Abstract

Concentrations of hexabromocyclododecanes (HBCDs) were determined in surface sediments of Shanghai, China. The concentrations of total HBCD diastereoisomers (ΣHBCD) ranged from 0.01 to 13.70 ng g(-1) dry weight (dw) with a mean value of 3.41 ng g(-1) dw, which was up to several orders of magnitude lower than those reported for sediments from European countries. The ΣHBCD concentrations in sediments from chemical/textile industrial or densely populated areas were generally higher than those from rural or less chemical/textile industrialized areas in Shanghai. A high proportion of α-HBCD was observed in sediment samples and was significantly higher than that of commercial HBCD products. This might be due to thermal isomerization from γ-HBCD to α-HBCD and slower degradation rate of α-HBCD compared to γ-HBCD in anaerobic conditions. The mass inventory of ΣHBCD in surface sediments of Shanghai was estimated at 164.4 kg, representing a significant source of HBCDs to the Shanghai environment. This indicates that further study on potential transfer of HBCDs from sediments to aquatic organisms and ecological risk assessments is required.

Determination of hexabromocyclododecanes in sediments from the Haihe River in China by an optimized HPLC–MS–MS method

“…Despite the existence of some industrial parks around the Haihe River, most of the examined sediments had not been affected yet. In contrast, the HBCD concentrations were lower in surface sediments from river drainage basins of Shanghai (Tang et al, 2015) when compared with those obtained in the present study. Likewise, the HBCD concentrations previously reported from other countries and regions in the Detroit River of North America (Letcher et al, 2015) and in coastal waters of Korea (Ramu et al, 2010) were lower than those obtained in this study.…”

Preliminary screening of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) flame retardants in landfill leachate

“…Furthermore, both α-HBCDD and β-HBCDD were also not detected at landfill sites 5, 6 and 7, only the gamma isomer was detected at these sites. The predominance of the γ-HBCDD in different environmental samples (Letcher et al 2015, Xiang et al 2015) and that of α-HBCDD in biological matrices (Ryan &Rawn 2014, Tang et al 2015) have been established. TBBPA, on the other hand, is a reactive BFR that is covalently bound to the polymeric material to which it has been applied.…”

“…Due to concerns over their environmental persistence, toxicity, bioaccumulation potential and their propensity to undergo long-range atmospheric transport, the production and use of the penta-, octa-BDEs as well as HBCDD technical formulations have been globally restricted (UNEP 2009). Presently, only TBBPA and deca-BDE technical formulations are still being produced, although there are concerns over the possible microbial mediated or photolytic breakdown of the deca-BDE congener to the more toxic lower brominated congeners (Daso et al 2010).…”

Assessing the cytotoxic effect of hexabromocyclododecane (HBCD) on liver tissue cultures from fathead minnow (Pimephales promelas)

“…HBCD has 6 stereogenic centers and is composed of 16 possible stereoisomers (6 enantiomeric pairs and 4 meso forms; Wang et al, 2013). The three most common forms of HBCD found in the environment are the α-, β-, γ-diastereomers (approximately 10 %-13 % α-HBCD, 1%-12 % β-HBCD, 75 %-89 % γ-HBCD; Tang et al, 2015).…”