Organophosphate esters in East Greenland polar bears and ringed seals: Adipose tissue concentrations and in vitro depletion and metabolite formation

• Published in: Chemosphere
• Main Authors: Strobel, A. (Adelle), Willmore, W. (William), Sonne, C. (Christian), Dietz, R. (Rune), Letcher, R.J. (Robert J.)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: East Greenland; In vitro metabolism; Liver and adipose tissue; Organophosphate esters (OPEs); Polar bear; Ringed seal; Arctic; Greenland; ringed seal
• Online Access: https://ir.library.carleton.ca/pub/17297; https://doi.org/10.1016/j.chemosphere.2017.12.181

East Greenland is a contamination “hot spot” for long-range transported anthropogenic chemicals, including organophosphate esters (OPEs). High concentrations of OPEs have been reported in arctic air while very little is known for wildlife where OPE tissue residues levels appear to be strongly influenced by biotransformation. In the present study, the hepatic in vitro metabolism of six environmentally relevant organophosphate (OP) triesters and corresponding OP diester formation were investigated in East Greenland polar bears (PBs) and ringed seals (RSs). The in vitro metabolism assay results were compared to adipose levels in field samples from the same individuals. In vitro OP triester metabolism was generally rapid and structure-dependent, where PBs metabolized OPEs more rapidly than RSs. Exceptions were the lack of triethyl phosphate (TEP) metabolism and slow metabolism of tris(2-ethylhexyl) phosphate (TEHP) in both species. OP diester metabolites were also formed with the exception of TEP which was not metabolized at all. Tris(1,3-dichloro-2-p