Bioaccumulation and bound-residue formation of14C-decabromodiphenyl ether in an earthworm-soil system.
Decabromodiphenyl ether (DecaBDE) is one of the most frequently detected flame retardants in terrestrial environments. However, the fate of DecaBDE and its transport in an earthworm-soil system with and without a DecaBDE-degrading strain have rarely been evaluated. In this study,14C-DecaBDE was self-synthesized, and a DBDE-degrading strain, Rhodococcus erythropolis, was used in an earthworm-soil system. DecaBDE showed limited degradation and mineralization after 35days of all treatments. The bound-residue (BR) formation in soil was <2.5% in the system containing earthworms, which was significantly higher (p<0.05) than that observed in the absence of earthworms (<0.45%). DecaBDE could be adsorbed by the earthworms with a BSAF of ≤0.31. The distribution of14C-DecaBDE concentrations in the earthworm roughly followed the pattern of crop gizzard>digestive system>head>tail>body wall, suggesting that DecaBDE was mainly uptaken through ingestion. Up to 31% of the14C-DecaBDE in the earthworms was not extractable, revealing that the total concentration of accumulated14C-DecaBDE was underestimated. The results also showed that the presence of DecaBDE-degrading bacteria did not significantly affect the fate of DecaBDE and its accumulation in earthworms. The study indicates that the conventional assessment of the bioaccumulation and ecological effects of DecaBDE, which is based only on extractable concentrations, may underestimate the risks.
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China.
Lei
L
Huang
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China. Electronic address: wei_wang@zju.edu.cn.
Wei
W
Wang
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China.
Sufen
S
Zhang
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China.
Shenghua
S
Tang
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China.
Pengfei
P
Zhao
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China. Electronic address: qfye@zju.edu.cn.
Qingfu
Q
Ye
D000818:Animals; D001673:Biodegradation, Environmental; D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers / Q000737:chemistry* / Q000378:metabolism; D009835:Oligochaeta / Q000378:metabolism*; D012240:Rhodococcus / Q000378:metabolism; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis; D014018:Tissue Distribution
D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers; D012987:Soil; D012989:Soil Pollutants; C010902:decabromobiphenyl ether
Bound residue; Decabromodiphenyl ether; Geophagous earthworm; Risk assessment; Soil