title: Baseline levels and trophic transfer of persistent organic pollutants in sediments and biota from the Congo River Basin (DR Congo).
abstract: The present study aimed to evaluate the occurrence of persistent organic pollutants (POPs: (PCBs, PBDEs, DDTs, HCHs, CHLs and HCB) in sediments and biota from the middle Congo River Basin (CRB) and to investigate their trophic transfer through the aquatic food web using nitrogen stable isotope ratios. To our knowledge, no data on levels of POPs in sediment and biota from the CRB are present in the literature, and studies on trophic transfer and biomagnification profiles of POPs using δ(15)N are scarce in tropical regions. POP levels in the sediment and biota were low, with exception of total PCB levels found in fish from the Itimbiri River (1.4 to 44ng/g ww). Compared to concentrations found in fish from pristine to relatively industrial developed areas, the ∑PCB levels in fish from the Itimbiri were high, indicating the presence of a local PCB contamination source in this catchment. Based on minimum risk level criteria formulated by ATSDR, the consumption of PCB contaminated fish from the Itimbiri river poses a potential risk for humans. The POP levels in biota were not significantly related to the POP levels in sediments, and the BSAF concept (Biota-Sediment Accumulation Factor) was found to be a poor predictor of the bioavailability and bioaccumulation of environmental pollutants in the present study. With increasing trophic levels, a significant increase in PCB 95, 101, 110, 138, 146, 149, 153, 174, 180 & 187 and p,p'-DDT in Itimbiri and BDE 47 & 99 in Itimbiri, Aruwimi & Lomami river basins was observed. Trophic magnification factors were higher than 1, indicating that biomagnification occurs through the tropical food web.
authors.affiliation: Systemic Physiological & Ecotoxicological Research, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium. vera.verhaert@ua.ac.be
authors.forename: Vera
authors.initials: V
authors.lastname: Verhaert
authors.forename: Adrian
authors.initials: A
authors.lastname: Covaci
authors.forename: Steven
authors.initials: S
authors.lastname: Bouillon
authors.forename: Katya
authors.initials: K
authors.lastname: Abrantes
authors.forename: Dieudonné
authors.initials: D
authors.lastname: Musibono
authors.forename: Lieven
authors.initials: L
authors.lastname: Bervoets
authors.forename: Erik
authors.initials: E
authors.lastname: Verheyen
authors.forename: Ronny
authors.initials: R
authors.lastname: Blust
mesh_terms: D000818:Animals; D058448:Biota; D003634:DDT / Q000032:analysis / Q000378:metabolism*; D015023:Democratic Republic of the Congo; D005399:Fishes; D020387:Food Chain; D019015:Geologic Sediments / Q000737:chemistry*; D055768:Halogenated Diphenyl Ethers / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D009587:Nitrogen Isotopes / Q000032:analysis / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000378:metabolism*; D045483:Rivers / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D055768:Halogenated Diphenyl Ethers; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D003634:DDT; D011078:Polychlorinated Biphenyls
keywords: Bioaccumulation; Congo River Basin; Persistent organic pollutants; Trophic magnification factors; Trophic transfer