title: Sorption and competition of two persistent organic pesticides onto marine sediments: Relevance to their distribution in aquatic system.
abstract: Sorption is a key process in the distribution of substances between environmental compartments in marine ecosystems. Two persistent organic pesticides, also known as toxaphene congeners, namely B8-1413 (P26) and B9-1679 (P50), are of special interest because they are not detected in sediments while relatively concentrated in marine mammals. Sorption-desorption, entrapment and competition behaviors of these pesticides onto marine sediments were studied to explain their environmental distribution. Data obtained under marine experimental conditions were fitted to sorption models to evaluate sorption coefficients and to assess the degree of B8-1413/B9-1679 entrapment of the two toxaphene congeners in sediments. Carbon normalized sorption coefficients (Koc) of both congeners were similar under in cold (2°C) marine (30 psu) conditions with high values ranging from 1.53×10(5) to 3.28×10(5) mL g(-1)indicative of a strong affinity to marine sediments However, the sorption-desorption investigations indicate that B8-1413/B9-1679 were on average 2.5 times less entrapped in sediments compared to B7-1450, a toxaphene congener known to accumulate predominantly in sediments. These results suggest that the low entrapment of B8-1413 and B9-1679 favor their availability and transfer to biological matrices.
authors.affiliation: Département de biologie, chimie et géographie, Université du Québec à Rimouski, 300, Allée des Ursulines, Rimouski, QC G5L 3A1, Canada; Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, 310, Allée des Ursulines, Rimouski, QC G5L 3A1, Canada. Electronic address: Youssoufdjibril_Soubaneh@uqar.ca.
authors.forename: Youssouf Djibril
authors.initials: YD
authors.lastname: Soubaneh
authors.affiliation: Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, 310, Allée des Ursulines, Rimouski, QC G5L 3A1, Canada.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Gagné
authors.affiliation: Department of Fisheries and Oceans, Maurice Lamontagne Institute, P.O. Box 1000, 850 Route de la Mer, Mont-Joli, QC G5H 3Z4, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Lebeuf
authors.affiliation: Saint-Petersburg Scientific Research Centre for Ecological Safety, Russian Academy of Sciences Korpusnaya, 18, St. Petersburg 197110, Russia.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Nikiforov
authors.affiliation: Aquatic Ecosystem Protection Research Division, Environment Canada, Burlington, ON L7R 4A6, Canada.
authors.forename: Bruno
authors.initials: B
authors.lastname: Gouteux
authors.affiliation: Laboratoire de Chimie, Institut des Sciences de la Terre, Centre d'Etude et de Recherche de Djibouti (CERD), Route de l'aéroport, B.P. 486, Djibouti.
authors.forename: Awaleh Mohamed
authors.initials: AM
authors.lastname: Osman
mesh_terms: D000327:Adsorption; D003080:Cold Temperature; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry*; D008962:Models, Theoretical; D010575:Pesticides / Q000032:analysis*; D054712:Salinity; D014112:Toxaphene / Q000032:analysis* / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical; D014112:Toxaphene
keywords: Aquatic ecosystem; Desorption–entrapment; P26/P50; POPs; Sorption coefficient