Hexabromocyclododecanes (HBCDDs) in surface soils from coastal cities in North China: Correlation between diastereoisomer profiles and industrial activities

Elucidating the Variability in the Hexabromocyclododecane Diastereomer Profile in the Global Environment

“…Note that such a relationship between emission source and dominant diastereomer agrees with observations in the vicinity of sources. For example, Zhang et al 8 observed the dominance of γ-HBCDD in soils surrounding HBCDD production facilities in Weifang (on average 71.8%) in China, whereas Gao et al 40 found that α-HBCDD is "obviously abundant" in soil samples collected from illegal e-waste treatment sites. In terms of ∑ 3 HBCDD, for the entire modeled period 1965−2100, cumulatively 290−620 t of emissions occur during the use of HBCDD-containing products (orange shades in Figure 5), and 145−150 t of emissions arise from end-of-life disposal of these products (red shades in Figure 5).…”

“…In addition, dominance of γ-HBCDD is also observed in cells with significant HBCDD production and processing, for example, cell #92 (white box in Figure 6a) encompassing Northern China which is the hub of Chinese HCBDD production. 8 By contrast, α-HBCDD is dominant in the atmosphere of several populated areas such as East and Southeast Asia, Western Europe and North America, because these areas are strongly influenced by emissions from the use and disposal of HBCDD-containing products, which are dominated by α-HBCDD. For example, our model predicts an α/γ ratio of 3.5 for cell #116 (white box in Figure 6a), which lies within the range of 2.2−3.6 observed in urban and suburban sites of Guangzhou (China) 12 (SI Table S1).…”

“…7 Among them, γ-HBCDD is the most abundant (with a typical mass fraction of 81.6%), followed by α-HBCDD (11.8%) and β-HBCDD (5.8%). 7 Such a γ-HBCDD-dominant diastereomer profile can explain dominance of γ-HBCDD observed in abiotic samples collected from industrial sites such as those in Weifang (China) 8 and Tianjin (China). 9 However, this γ-HBCDDdominant diastereomer profile has also been observed in remote background areas such as Ny-Ålesund (Norway) 10 and Sleeping Bear Dunes (the United States) 11 which are far from industrial activities.…”

“…As such, the production and use of heat-treated HBCDD-containing products, instead of the technical mixture itself, can be hypothesized to explain the dominance of α-HBCDD observed in the environment. For example, in an investigation of diastereomer profiles in soils across 21 Chinese coastal cities, Zhang et al 8 linked the dominance of α-HBCDD in Cangzhou and Tianjin to these cities hosting the largest XPS-based boards/pipeline manufacturing and cutting site in China, and the largest e-waste recycling area in Northern China, respectively. Whereas these studies provide valuable information on how human activities determine diastereomer profile of HBCDD in the local or regional environment, it still remains to be explored to what extent isomerization influences the fate of HBCDD diastereomers globally, and in particular, how such small-scale processes interact with environmental factors to shape the big picture of HBCDD emissions and occurrence on a global scale.…”

Traditional and new POPs in environments along the Bohai and Yellow Seas: An overview of China and South Korea

“…HBCDs in soils from coastal cities along the Bohai and Yellow Seas were reported (Zhang et al, 2016). Concentrations of HBCDs ranged from 0.12 ng g À1 dw to 363 ng g À1 dw.…”