Fifty-two　PBDE　congeners　in　river　sediments　from　Shanghai　were　analyzed　in　the　present　study.　The　concentrations　of　Sigma　51PBDEs　(defined　as　the　sum　of　51　BDE　congeners　except　BDE209)　and　BDE209　ranged　from　0.231　to　119　ng　g(-1)　and　from　nd　to　189　ng　g(-1),　respectively.　The　most　abundant　BDE　congeners　in　surface　sediments　were　BDE118,　207,　208,　99,　49,　75,　47,　71　and　209,　with　median　values　of　1.67,　1.81,　1.83,　1.87,　1.98,　2.52,　2.73,　4.62　and　45.7　ng　g(-1)　dw,　respectively.　The　concentrations　of　Sigma　52PBDEs　were　significantly　correlated　with　total　organic　carbon　(TOC)　content　in　sediments　(p　＜　0.05).　Weak　correlations　between　all　PBDE　homologues　and　TOC　(r　＜　0.32)　suggest　that　TOC　had　a　little　influence　on　sediment　PBDE　transport　and　distribution　patterns　in　river　sediments　of　Shanghai.　Correspondence　analysis　(CA)　showed　that　PBDEs　in　sediments　in　the　studied　area　originated　from　commercial　BDE　formulations,　combustion　emission　sources,　and　debromination　of　highly　brominated　PBDEs　by　aerobic/anaerobic　microbes　or　sunlight.　Risk　assessment　based　on　risk　quotients　(RQ)　showed　that　PBDEs　in　all　river　sediments　collected　from　Shanghai　posed　a　high　potential　ecological　risk　(RQ　＞　1)　to　the　sediment　dwelling　organisms,　and　pentaBDE,　decaBDE　and　tetraBDE　were　the　major　ecological　risk　drivers.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.