title: Spatially resolved distribution models of POP concentrations in soil: a stochastic approach using regression trees.
abstract: Background concentrations of selected persistent organic pollutants (polychlorinated biphenyls, hexachlorobenzene, p,p'-DDT including metabolites) and polyaromatic hydrocarbons in soils of the Czech Republic were predicted in this study, and the main factors affecting their geographical distribution were identified. A database containing POP concentrations in 534 soil samples and the set of specific environmental predictors were used for development of a model based on regression trees. Selected predictors addressed specific conditions affecting a behavior of the individual groups of pollutants: a presence of primary and secondary sources, density of human settlement, geographical characteristics and climatic conditions, land use, land cover, and soil properties. The model explained a high portion of variability in relationship between the soil concentrations of selected organic pollutants and available predictors. A tree for hexachlorobenzene was the most successful with 76.2% of explained variability, followed by trees for polyaromatic hydrocarbons (71%), polychlorinated biphenyls (68.6%), and p,p'-DDT and metabolites (65.4%). The validation results confirmed that the model is stable, general and useful for prediction. The stochastic model applied in this study seems to be a promising tool capable of predicting the environmental distribution of organic pollutants.
authors.affiliation: Research Centre for Environmental Chemistry and Toxicology, Kamenice 126/3, 625 00 Brno, Czech Republic.
authors.forename: Klára
authors.initials: K
authors.lastname: Kubosová
authors.forename: Jirí
authors.initials: J
authors.lastname: Komprda
authors.forename: Jirí
authors.initials: J
authors.lastname: Jarkovský
authors.forename: Milan
authors.initials: M
authors.lastname: Sánka
authors.forename: Ondrej
authors.initials: O
authors.lastname: Hájek
authors.forename: Ladislav
authors.initials: L
authors.lastname: Dusek
authors.forename: Ivan
authors.initials: I
authors.lastname: Holoubek
authors.forename: Jana
authors.initials: J
authors.lastname: Klánová
mesh_terms: D002244:Carbon / Q000737:chemistry; D018153:Czech Republic; D003634:DDT / Q000032:analysis*; D005659:Fungicides, Industrial / Q000032:analysis*; D006581:Hexachlorobenzene / Q000032:analysis*; D006801:Humans; D008956:Models, Chemical; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D012044:Regression Analysis; D012989:Soil Pollutants / Q000032:analysis*; D013269:Stochastic Processes
chemical_list: D005659:Fungicides, Industrial; D012989:Soil Pollutants; D006581:Hexachlorobenzene; D002244:Carbon; D003634:DDT; D011078:Polychlorinated Biphenyls