Combined Toxicological Effect Of Decabromodiphenyl Ether And Copper Pollution On Eisenia Fetida

Polybrominated diphenyl ethers (PBDEs) and heavy metals were determined in soil or around e-waste recycling site, among these contaminants decabromodiphenyl ether (BDE209) and lead (Pb) were widespread, yet their combined effect on earthworms within the soil was not reported. So in this study, the effects combined pollution of BDE209and Pb at different concentrations on Eisenia fetida, accumulation and transformation of contaminant and toxicological effect were studied under laboratory conditions. Our results are showed as follow:(1) The results have demonstrated that Pb addition can affect BDE209bioaccumulation and transformation efficiency compared with exposure to BDE209alone. For a high BDE209concentration (100mg/kg), a higher level of Pb (250and500mg/kg) facilitated the uptake of BDE209through the skin. The peak of BDE209accumulation usually appeared in the joint exposure groups involving250mg/kg Pb. The earthworms eliminated more BDE209after21days, and the biodegradation products were mainly BDE206and BDE208. Meanwhile, the results have also indicated that BDE209presence can affect Pb bioaccumulation efficiency compared with exposure to Pb alone. For the different Pb doses, almost contrary response trends were found for Pb uptake examined separately on day7or28. After7days of exposure, the earthworm receiving1mg/kg BDE209showed significantly lower Pb contents, however, as the incubation time extend, the influence of BDE209presence on Pb uptake gradually declined.(2) Electron paramagnetic resonance (EPR) spectra indicated that·OH in earthworms were significantly induced by Pb in the presence of BDE209after7days of exposure; however, as the experimental duration extended, almost contrary response trends were found in·OH intensity. Furthermore, the changing pattern of malondialdehyde (MDA) contents was accordant with that of·OH intensity. For a low Pb concentration (50mg/kg), BDE209addition barely affected the SOD and CAT activities compared with exposure to Pb alone; whereas for a higher level of Pb (250and500mg/kg), BDE209addition decreased the enzyme activities. Finally, the joint Pb and BDE209exposure can affect the protein synthesis in earthworms.(3) The combined exposure can cause earthworm cell damage, and obvious dose effect relationship was observed between the damage degree and Pb content in earthworms. BDE209addition can inhibit the earthworm cell DNA damage, furthermore BDE209and Pb presented antagonism.