Polybrominated diphenyl ethers (PBDEs) in gammarids, caddisflies, and bed sediments of the lowland River Po

Polybrominated diphenyl ethers (PBDEs) were investigated in sediments and invertebrates (gammarids and caddisflies) collected in the River Po, upstream and downstream from a polluted tributary. Besides a diffuse contamination by penta-BDE technical mixture, the river sediments identified the tributary as an important source to the main river of decabromodiphenyl ether (BDE-209), which peaked to 64 μg/g (OC) in the downstream stretch. At 10 km downstream from the tributary, a higher bioavailability was evident than at 22 km, and small gammarids accumulated at two/three times the levels of PBDEs found in large gammarids. The congener profiles of sediments and invertebrates were dominated by BDE-47, BDE-99 and BDE-209.