Biomonitoring of wild cetaceans for persistent organic pollutants (POPs) is heavily reliant on concentrations determined in blubber, and there are few data relating blubber concentrations and levels in blood. Matched blubber and plasma samples (n=56) were collected from free-ranging common bottlenose dolphins (Tursiops truncatus) and analyzed for 61 polychlorinated biphenyl (PCB) congeners, 5 polybrominated diphenyl ether (PBDE) congeners and 13 organochlorine pesticides (OCPs). With the exception of PCB 209, lipid-normalized concentrations of the major POPs in blubber and plasma were positively and significantly correlated amongst all dolphins (R2= 0.828 to 0.976). Relative plasma concentrations, however, were found to significantly increase with declining blubber lipid content, suggesting that as blubber lipid is utilized, POPs are mobilized into blood. Compound- and homolog- specific blubber/blood partition coefficients also differed according to lipid content, suggesting certain POPs are selectively mobilized from blubber. The results of this study suggest that with use of the regression parameters derived here, blubber may be used to estimate blood concentrations and vice-versa. Additionally, the mobilization of POPs from blubber and concomitant increase in contaminants in blood suggests cetaceans with reduced blubber lipid may be at a greater risk for contaminant-associated health effects.
Citation: Environmental Science & Technology
Pub Type: Journals
blood, blubber, bottlenose dolphin, persistent organic pollutants