title: Humic acid toxicity in biologically treated soil contaminated with polycyclic aromatic hydrocarbons and pentachlorophenol.
abstract: Contaminated soil from a land treatment unit at the Libby Groundwater Superfund Site in Libby, MT, was amended with 14C pyrene and incubated for 396 days to promote biodegradation and the formation of soil-associated bound residues. Humic and fulvic acids were extracted from the treated soil microcosms and analyzed for the presence of pyrene residues. Biologic activity promoted 14C association with the fulvic acid fraction, but humic acid-associated 14C did not increase with biologic activity. The Aboatox flash toxicity assay was used to assess the toxicity of humic and fulvic acid fractions. The fulvic acid gave no toxic response, but the humic acid showed significant toxicity. The observed toxicity was likely associated with pentachlorophenol, a known contaminant of the soil that was removed by solvent extraction of the humic acid and that correlated well with toxicity reduction.
authors.affiliation: Utah Water Research Laboratory, Utah State University, Logan, Utah, 84322-8200, USA.
authors.forename: J K C
authors.initials: JK
authors.lastname: Nieman
authors.forename: R C
authors.initials: RC
authors.lastname: Sims
authors.forename: D L
authors.initials: DL
authors.lastname: Sorensen
authors.forename: J E
authors.initials: JE
authors.lastname: McLean
mesh_terms: D048908:Aliivibrio fischeri; D001578:Benzopyrans; D001673:Biodegradation, Environmental; D002250:Carbon Radioisotopes; D003247:Conservation of Natural Resources; D006256:Hazardous Waste; D006812:Humic Substances; D009009:Montana; D010416:Pentachlorophenol / Q000378:metabolism; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism; D011721:Pyrenes / Q000032:analysis / Q000378:metabolism; D018570:Risk Assessment / Q000379:methods; D012987:Soil; D012989:Soil Pollutants / Q000378:metabolism; D023382:Toxicity Tests, Acute
chemical_list: D001578:Benzopyrans; D002250:Carbon Radioisotopes; D006256:Hazardous Waste; D006812:Humic Substances; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C030984:pyrene; D010416:Pentachlorophenol; C005023:fulvic acid