PARTITIONING OF PERSISTENT ORGANIC POLLUTANTS (POPs) BETWEEN BLUBBER AND BLOOD OF WILD BOTTLENOSE DOLPHINS: IMPLICATIONS FOR BIOMONITORING AND HEALTH

Jennifer E. YordyΔ,†, Randall S. Wells§, Brian C. Balmer§, Lori H. Schwacke,

Teri K. Rowles°, John R. Kucklick

 

ΔMedical University of South Carolina, Charleston, SC

NIST, Hollings Marine Laboratory, Charleston, SC

§Chicago Zoological Society c/o Mote Marine Laboratory, Sarasota, FL, USA

NOAA, National Ocean Service, Center for Human Health Risks, Charleston, SC, USA

°NOAA, National Marine Fisheries Service, Silver Spring, MD

 

 

Biomonitoring surveys of wild cetaceans commonly utilize blubber as a means to assess exposure to persistent organic pollutants (POPs), but there are few data to support the relationship between concentrations in blubber and those in blood, which is a better indicator of target organ exposure. To define this relationship, matched blubber and plasma samples (n = 56) were collected from free-ranging 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 (R2= 0.828 to 0.976). Plasma concentrations, however, significantly increased with declining blubber lipid content, suggesting that as lipid is utilized, POPs are mobilized into blood. Compound- and homolog- specific blubber/blood partition coefficients also differed according to lipid content, suggesting POPs are selectively mobilized from blubber. Overall, these results suggest that with 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 greater risk for contaminant-associated health effects.