title: Enantiomeric fraction and isomeric composition to assess sources of DDT residues in soils.
abstract: Chiral pesticides such as o,p'-DDT can undergo enantioselective microbial degradation in soil. Hence, the enantiomeric fraction (EF) of o,p'-DDT was used as an approach to assess potential recent inputs of DDT in the lower part of the Ebro River basin (NE Spain), a region heavily impacted by agricultural and industrial activities, including a dicofol production and a chloro-alkali plants. The EFs of five out of nineteen soils were not different from the racemic value (0.505±0.010), confirming that the Ebro River and some of its tributaries, Segre and Cinca rivers, transported fresh DDT residues despite its ban in Spain during the 90 s. o,p'-DDT/p,p'-DDT ratios in soils suggest that recent use of technical DDT and/or DDT-contaminated dicofol may be responsible for the fresh DDT inputs in the Segre River, while in the Ebro River, they indicate a dominant contribution of technical DDT, likely related to the residues accumulated by the chloro-alkali plant discharges.
authors.affiliation: Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDÆA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia, Spain. Electronic address: carme.bosch@gmail.com.
authors.forename: Carme
authors.initials: C
authors.lastname: Bosch
authors.affiliation: Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDÆA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia, Spain. Electronic address: joan.grimalt@cid.csic.es.
authors.forename: Joan O
authors.initials: JO
authors.lastname: Grimalt
authors.affiliation: Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDÆA), Spanish Council for Scientific Research (CSIC), Jordi Girona 18, 08034 Barcelona, Catalonia, Spain. Electronic address: pilar.fernandez@cid.csic.es.
authors.forename: Pilar
authors.initials: P
authors.lastname: Fernández
mesh_terms: D000383:Agriculture; D003634:DDT / Q000032:analysis* / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D010575:Pesticides / Q000032:analysis*; D045483:Rivers; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013030:Spain; D013237:Stereoisomerism
chemical_list: D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; D003634:DDT; C016340:o,p'-DDT
keywords: Chiral pesticides; DDT pollution in soils; Dicofol; Enantiomeric fraction; o,p′-DDT