Polybrominated Diphenyl Ethers in the Sediments of the Great Lakes. 4. Influencing Factors, Trends, and Implications

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119

The concentrations of 13 currently used brominated flame retardants (BFRs) were analyzed in 16 sediment cores collected from the North American Great Lakes. Among them, 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE), decabromodiphenyl ethane (DBDPE), hexabromocyclododecane (HBCD), 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), and hexachlorocyclopentadienyl dibromocyclooctane (HCDBCO) were more frequently detected than others. In general, these emerging BFRs have much lower concentrations than polybromodiphenyl ethers (PBDEs) and dechloranes. Inventories of the five BFRs named above, given on a logarithm basis, were found to decrease linearly with the increasing latitude of the sampling locations, but with weaker statistics than those previously reported for the dechloranes. Logarithm of surface fluxes, on the other hand, was found to be a better parameter in correlating with the longitude. With regard to time trends, the exponential increases in concentrations of these BFRs, particularly DBDPE and BTBPE, in recent years are particularly disturbing. The sediment concentration of DBDPE doubles every 3−5 years in Lake Michigan, and approximately every 7 years in Lake Ontario. The corresponding doubling times for BTBPE are about 5 and 7 years in Lakes Ontario and Michigan, respectively, although declines or leveling off were observed in the top sediment layers in Lake Ontario. In contrast to PCBs, PBDEs, and most dechloranes, the correlations between the surface concentration of emerging BFRs and the latitude or longitude of the sampling sites were not strengthened by normalization of the concentration based on the organic matter content of the sediment.

Section: ■ Experimental Sectionsupporting

confidence: 87%

Emerging Brominated Flame Retardants in the Sediment of the Great Lakes

Yang

Wei

Guo

et al. 2012

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119

“…Detailed dry weight based concentration data for the surface sediments from the present study are presented in SI Table S3, while a summary of the results from the previous and present studies is in SI Table S4, . 16 The concentrations of BDE-209 were 1.9−50 (mean: 18) ng g −1 in Daya Bay and 1.5−53 (mean: 16) ng g −1 in Hong Kong, generally lower than those found in other regions, e.g., 21−242 ng g −1 in the Great Lakes 15 and 240−1650 ng g −1 in Scheldt Estuary of The Netherlands, 9 and much lower than those (0−7300 ng g −1 ) within the PRD region. 17 Overall, the levels of sediment contamination by PBDEs in the two sampling regions of the present study were moderate as compared to the global range.…”

Section: ■ Results and Discussionmentioning

confidence: 95%

Occurrence of Halogenated Flame Retardants in Sediment off an Urbanized Coastal Zone: Association with Urbanization and Industrialization

Liu

Luo

et al. 2014

To examine the impacts of urbanization and industrialization on the coastal environment, sediment samples were collected from an urbanized coastal zone (i.e., Daya Bay and Hong Kong waters of South China) and analyzed for 20 polybrominated diphenyl ethers (PBDEs) and 10 alternative halogenated flame retardants (AHFRs). The sum concentration of PBDEs was in the range of 1.7−55 (mean: 17) ng g −1 , suggesting a moderate pollution level compared to the global range. The higher fractions of AHFRs (i.e., TBB+TBPH, BTBPE and DBDPE) than those of legacy PBDEs (i.e., penta-BDE, octa-BDE and deca-BDE) corresponded with the phasing out of PBDEs and increasing demand for AHFRs. Heavy contamination occurred at the estuary of Dan'ao River flowing through the Daya Bay Economic Zone, home to a variety of petrochemicals and electronics manufacturing facilities. The concentrations of HFRs in surface sediments of Hong Kong were the highest in Victoria Harbor, which receives around 1.4 million tons of primarily treated sewage daily, and a good relationship (r 2 = 0.80; p < 0.0001) between the HFR concentration and population density in each council district was observed, highlighting the effect of urbanization. Moreover, the AHFR concentrations were significantly correlated (r 2 > 0.73; p < 0.05) with the production volume of electronic devices, production value of electronic industries and population size, demonstrating the importance of industrializing and urbanizing processes in dictating the historical input patterns of AHFRs.

“…South-to-north and east-to-west log-linear decreasing gradients have been reported for PCBs and PBDEs in the sediments of the Great Lakes. 13,17 As shown in Figure 2, the inventory of mirex in sediment is a strong function of the latitude and longitude of the sampling locations. The surface concentration and flux are also dependent on the latitude and longitude but with slightly weaker statistics (SI Table S4).…”

Section: ' Results and Discussionmentioning

confidence: 99%

“…Standards of syn-DP and anti-DP were purchased from Wellington laboratories Inc. (Guelph, ON, Canada). Mirex and the surrogate 13 C-labeled PCB209 (PCB209L) and internal standard 13 C-labled PCB205 (PCB205L) were purchased from Cambridge Isotope Laboratories Inc. (Andover, MA). Kepone (>99% purity) and surrogate 2,4,4 0 -tribromodiphenyl ether (BDE30) was purchased from Environmental Science & Technology ARTICLE AccuStandard (New Haven, CT).…”

mentioning

confidence: 99%

Historically and Currently Used Dechloranes in the Sediments of the Great Lakes

Yang

Wei

Guo

et al. 2011

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Dechlorane (mirex), Dechlorane Plus (DP), Dechlorane 602 (Dec602), Dechlorane 603 (Dec603), Dechlorane 604 (Dec604), and Chlordecone (Kepone) were analyzed in 16 sediment cores collected in 2007 from the Great Lakes of North America. Results show that Lake Ontario sediments have accumulated mirex, DP, Dec602 and Dec604 in amounts 1 to 2 orders of magnitude higher than other Great Lakes. The chemical inventory decreases logÀlinearly with increasing latitude (N) and longitude (W) of the sampling locations, but Lake Ontario sites are outliers in the regression against latitude. The regression analyses suggest differences among the analytes with regard to source impact and long-range transport behavior. Temporal trends of input differ among lakes. Most sites in Lake Superior are still receiving increasing fluxes of DP and Dec602, while these have been declining in Lake Ontario from the peak around 1990. The relative abundance of the two DP isomers, represented by f syn , increases with increasing distance from the potential discharge source in Niagara Falls, NY, suggesting the anti-DP isomer is more vulnerable to degradation during long-range atmospheric transport. Kepone was not detected in the sediments of Lakes Ontario, Erie, and Michigan.