Occurrence of anthropogenic and naturally-produced organohalogenated compounds in tissues of Black Sea harbour porpoises

Abstract

a b s t r a c tHarbour porpoises are one of the three cetacean species inhabiting the Black Sea. This is the first study to report on polybrominated diphenyl ethers (PBDEs) and naturally-produced compounds, methoxylated PBDEs (MeO-PBDEs) and polybrominated hexahydroxanthene derivatives (PBHDs), in tissues (kidney, brain, blubber, liver, muscle) of male harbour porpoises (11 adults, 9 juveniles) from the Black Sea. Lipid-normalized concentrations decreased from muscle > blubber > liver > kidney > brain for the sum of polychlorinated biphenyls (PCBs) and for the sum of PBDEs. Among the naturally-produced compounds, levels of PBHDs were higher than of MeO-PBDEs, with tri-BHD and 6-MeO-BDE 47 being the dominant compounds for both groups, respectively. Concentrations of naturally-produced compounds decreased from blubber to brain, similarly to the sum of DDT and metabolites (DDXs). Concentrations of DDXs were highest, followed by PCBs, HCB, PBHDs, PBDEs and MeO-PBDEs. Levels of PCBs and PBDEs in blubber were lower than concentrations reported for harbour porpoises from the North Sea, while concentrations of DDXs were higher.

A non-invasive approach to study lifetime exposure and bioaccumulation of PCBs in protected marine mammals: PBPK modeling in harbor porpoises

“…Biochemical parameters were adjusted according to the specific PCB (Table 1). Blood/tissue partition coefficients were calculated using the approach from Parham et al (1997) and the average lipid percentage of the tissues which can be found in Weijs et al (2010a). However, blood/ brain partition coefficients (PB) calculated with this approach overestimated the levels of the PCBs in the brain of the Black Sea harbor porpoises and were therefore fitted to the data of the brain.…”

“…c Equations from Parham et al (1997) were transformed to equations for bottlenose dolphins (blood composition from Bossart et al (2001)). For partition coefficients of tissues (liver, kidneys, brain) as given in Table 1, the average lipid content was used (Weijs et al, 2010a). For the 'rest of the body'-compartment, the average lipid content of muscle was used (Weijs et al, 2010a of the model outcome as these parameters are more mathematically justified than biologically inspired.…”

“…For partition coefficients of tissues (liver, kidneys, brain) as given in Table 1, the average lipid content was used (Weijs et al, 2010a). For the 'rest of the body'-compartment, the average lipid content of muscle was used (Weijs et al, 2010a of the model outcome as these parameters are more mathematically justified than biologically inspired. Therefore, this procedure was kept to a minimum and only employed in cases where there were no parameters available in the literature or where the parameters (the models) did not match the real-life data from the harbor porpoises.…”

“…Carcasses were in good condition or only moderately composed and none of the animals was severely emaciated. Levels in blubber, liver, kidney, brain and muscle are discussed in Weijs et al (2010a). Levels of one neonate/fetus (Table 1) were used as well together with the levels of PCBs in milk of Black Sea harbor porpoises (Table S1).…”

“…This method is based on the lipid percentage of the respective tissues (Weijs et al, 2010a) which is the most logical background for the partitioning of lipophilic compounds. All calculated tissue/blood partition coefficients worked nicely for all PCBs, except for the blood/brain partition coefficients.…”