title: Storage and source of polycyclic aromatic hydrocarbons in sediments downstream of a major coal district in France.
abstract: During the 20th century, the local economy of the Upper Loire Basin (ULB) was essentially based on industrial coal mining extraction. One of the major French coal districts with associated urban/industrial activities and numerous coking/gas plants were developed in the Ondaine-Furan subbasins, two tributaries of the upper Loire main stream. To determine the compositional assemblage, the level and the potential sources of contamination, the historical sedimentary chronicle of the 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) has been investigated. PAH concentrations were determined using gas chromatography/mass spectrometry (GC/MS) in a dated core, sampled in the Villerest flood-control reservoir located downstream of the Ondaine-Furan corridor (OFC). The most contaminated sediments were deposited prior to 1983 (Σ16PAHs ca. 4429-13,348 ng/g) and during flood events (Σ16PAHs ca. 6380 ng/g - 1996 flood; 5360 ng/g - 2003 flood; 6075 ng/g - 2008 flood), especially in medium and high molecular weight PAHs. Among them, typical pyrogenic PAHs such as FLT, PYR, BbF and BaP were prevalent in most of the core samples. In addition, some PAHs last decade data is available from the Loire Bretagne Water Agency and were analyzed using high-performance liquid chromatography with postcolumn fluorescence derivatization (HPLC/FLD). These results confirm that the most highly contaminated sediments were found downstream of OFC (Σ16PAHs ca. 2264-7460 ng/g). According to the observed molecular distribution, PAHs are originated largely from high-temperature pyrolytic processes. Major sources of pyrogenic PAHs have been emphasized by calculation of specific ratios and by comparison to reported data. Atmospheric deposition of urban and industrial areas, wood combustion and degraded coal tar derived from former factories of coking/gas plants seem to be the major pyrogenic sources. Specifically, particular solid transport conditions that can occur during major flood events lead us to emphasize weathering of former contamination sources, such as more preserved coal tar.
authors.affiliation: Université François Rabelais de Tours, EA 6293 GéHCO, Parc de Grandmont, 37200 Tours, France; CNRS/INSU, ISTO, UMR 7327, 45071 Orléans, France. Electronic address: olivia.bertrand@cnrs-orleans.fr.
authors.forename: O
authors.initials: O
authors.lastname: Bertrand
authors.affiliation: Université de Poitiers, UMR 7285 IC2MP, 4 rue Michel Brunet, 86022 Poitiers Cedex, France.
authors.forename: L
authors.initials: L
authors.lastname: Mondamert
authors.affiliation: Université François Rabelais de Tours, EA 6293 GéHCO, Parc de Grandmont, 37200 Tours, France.
authors.forename: C
authors.initials: C
authors.lastname: Grosbois
authors.affiliation: Université François Rabelais de Tours, EA 6293 GéHCO, Parc de Grandmont, 37200 Tours, France.
authors.forename: E
authors.initials: E
authors.lastname: Dhivert
authors.affiliation: Agence de l'Eau Loire-Bretagne, 9 Avenue Buffon, CS 36339, 45063 Orléans Cedex 2, France.
authors.forename: X
authors.initials: X
authors.lastname: Bourrain
authors.affiliation: Université de Poitiers, UMR 7285 IC2MP, 4 rue Michel Brunet, 86022 Poitiers Cedex, France.
authors.forename: J
authors.initials: J
authors.lastname: Labanowski
authors.affiliation: Université François Rabelais de Tours, EA 6293 GéHCO, Parc de Grandmont, 37200 Tours, France.
authors.forename: M
authors.initials: M
authors.lastname: Desmet
mesh_terms: D003032:Coal Mining; D003033:Coal Tar / Q000032:analysis; D003077:Coke; D004784:Environmental Monitoring / Q000379:methods; D004787:Environmental Pollution / Q000032:analysis*; D055868:Floods; D005602:France; D008401:Gas Chromatography-Mass Spectrometry; D019015:Geologic Sediments / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000633:toxicity; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D003077:Coke; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D003033:Coal Tar
keywords: Bed sediments; Coal district; Loire river; Polycyclic aromatic hydrocarbon; Sediment core