POLYBROMINATED DIPHENYL ETHERS (PBDES) AND POLYCHLORINATED BIPHENYLS (PCBS) IN 0+ JUVENILE CYPRINIDS AND SEDIMENTS OF THE PO RIVER

PBDE and PCB content has been determined in
0+ bleak (Cyprinus alburnus), nase (Chondrostoma soetta),
gudgeon (Cyprinus gobio), chub (Cyprinus cephalus), and
barbel (Barbus sp.) as well as in bed sediments sampled
from the River Po upstream and downstream of the confluence
of a tributary draining a highly industrialized and
urbanized subbasin. Both groups of chemicals were present
at higher levels in fish and sediments downstream from the
confluence. In addition, whole-body concentrations of
PBDEs and PCBs were different among species despite the
young specimen age. The fact that PBDEs and PCBs were
higher in benthivorous versus planktivorous fish, as well as
in carnivorous versus herbivorous species, suggests that
feeding behavior is a major controlling factor that may help
differentiate the accumulation levels of 0+ juveniles. Of the
five species, the pelagic/planktivorous cyprinid bleak (C.
alburnus) showed the lowest concentrations (111 ng
PBDE/g lipid weight [l.w.], 2016 ng PCB/g l.w.), whereas
the benthic dweller and feeder barbel (Barbus sp.) had the
highest concentrations of both groups of chemicals (259 ng
PBDE/g l.w., 4785 ng PCB/g l.w.). The rank order of
species contamination was essentially stable upstream and
downstream from the tributary, and the congener contribution
of PBDEs was also similar. In general, BDE-47 was
the dominant congener, followed by BDE-100, -154, -153,
and -28. BDE-209 dominated the PBDE congener profiles
of sediments but was not found in any fish sample. Conversely,
an unidentified hexa-BDE congener, which was
not detected in sediments, was found in all fish species. The
levels of PBDEs and PCBs determined in adult goby
(Padogobius martensii), a small demersal predator also
examined in the same river stretches, provided additional
useful insights with which to interpret results.