title: Residues of organochlorine pesticides in Alabama soils.
abstract: A survey was made of 36 Alabama agricultural soils to assess residues of formerly used organochlorine pesticides. Compounds determined comprised alpha- and gamma-hexachlorocyclohexane, heptachlor, heptachlor-exo-epoxide, trans- and cis-chlordane, trans-nonachlor, dieldrin, toxaphene, DDT and DDE. Concentrations varied by several orders of magnitude among farms and appeared to be log-normally distributed. Highest concentrations (ng g(-1) dry soil, arithmetic means) were found for toxaphene (285+/-390) and DDTs (p,p'-DDE, 22.7+/-21.4; p,p'-DDT, 24.6+/-30.5; o,p'-DDT, 4.00+/-5.86; p,p'-DDD, 2.40+/-2.41) which were once heavily used in the southern USA. Pesticide residues were not proportional to soil organic carbon content indicating that residue concentrations were a reflection of pesticide application history and dissipation rates rather than air-soil equilibrium. Mean ratios of DDT/DDE in six regions of the state ranged from 0.39 to 1.5, and compound ratios for chlordanes and toxaphene were different from those in the technical mixtures.
authors.affiliation: Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, Canada M5S 3E5. t.harner@lancaster.ac.uk
authors.forename: T
authors.initials: T
authors.lastname: Harner
authors.forename: J L
authors.initials: JL
authors.lastname: Wideman
authors.forename: L M
authors.initials: LM
authors.lastname: Jantunen
authors.forename: T F
authors.initials: TF
authors.lastname: Bidleman
authors.forename: W J
authors.initials: WJ
authors.lastname: Parkhurst