Assessment of persistent organic pollutants (POPs) in sediments of the Eastern Indian Ocean

The concentrations of persistent organic pollutants (POPs) in sediments from the Eastern Indian Ocean were analyzed by GC-MS/MS to explore the status of contamination, distribution and their potential sources and risk. The average (+/- SD) concentrations of total polycyclic aromatic hydrocarbons (Sigma(16)PAHs), polybrominated diphenyl ethers (Sigma 10PBDEs),dedllorane plus (Sigma 2DP), organochlorine pesticides (Sigma(22)OCPs) and polychlorinated biphenyls (Sigma(31)PCBs) in sediments were 79,900 +/- 31,400, 173 +/- 62,42 +/- 24, 1051 +/- 305 and 147 +/- 24 pg g(-1) dw (or 11,200 +/- 7200, 28 +/- 26, 6 +/- 6, 168 +/- 121 and 24 +/- 17 ng g(-1) organic carbon), respectively. The concentrations of POPs in sediments were generally at low to median levels compared to those recorded in other ocean sediments. Composition analyses suggest that PAHs originate from both petrogenic and pyrogenic sources, while dichlorodiphenyltrichloroethane (DDT) mainly comes from technical-DDT, hexachlorocyclohexane (HCH) from I indane, and chlordane from fresh inputs.The risk assessments show that the targeted chemicals except for chlordane and naphthalene in sediments do not pose potential biological effects to the organisms in the Eastern Indian Ocean. The present study contributes to the very rare data on PAHs. PBDEs, DP, OCPs and PCBs in the vast deepocean and will deepen our knowledge of the fate of POPs in ocean environments. (C) 2019 Elsevier B.V. All rights reserved.