title: Bioavailability and toxicity of pyrene in soils upon biochar and compost addition.
abstract: The study investigates the role of biochar and/or compost in mitigating the toxic effects of pyrene in soils using reproduction of nematodes and porewater concentration as measures of pyrene toxicity and bioavailability, respectively. Two soils were spiked with increasing levels of pyrene to achieve a concentration-response relationship for the reproduction of Caenorhabditis elegans. The observed EC50 values (pyrene concentration causing 50% inhibition of reproduction) were 14mg/kg and 31mg/kg (dry mass) for these soils, corresponding to equilibrium porewater concentrations of 37μg/L and 47μg/L, respectively. Differences in organic carbon content were not sufficient to explain the variability in toxicity between the different soils. Soils causing a significant inhibition of reproduction were further amended with 10%-compost, 5%-biochar, or both, and the effects on reproduction and porewater concentration determined. Combined addition of compost and biochar was identified as the most effective strategy in reducing pyrene concentration in soil porewater, which was also partly reflected in soil toxicity. However, porewater concentrations predicted only 52% of pyrene toxicity to nematodes, pointing to particle-bound or dietary exposure pathways. Capsule: Amending pyrene-spiked soil with biochar and compost effectively reduced pyrene porewater concentrations and toxicity to nematodes, which were significantly related.
authors.affiliation: RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic. Electronic address: bielska@recetox.muni.cz.
authors.forename: Lucie
authors.initials: L
authors.lastname: Bielská
authors.affiliation: Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. Electronic address: melanie.kah@univie.ac.at.
authors.forename: Melanie
authors.initials: M
authors.lastname: Kah
authors.affiliation: Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. Electronic address: gabriel.sigmund@univie.ac.at.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Sigmund
authors.affiliation: Department of Environmental Geosciences, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. Electronic address: thilo.hofmann@univie.ac.at.
authors.forename: Thilo
authors.initials: T
authors.lastname: Hofmann
authors.affiliation: Institute of Biodiversity - Network, Nußbergerstr. 6a, 93059 Regensburg, Germany; Ecossa, Giselastr. 6, 82319 Starnberg, Germany. Electronic address: hoess@ecossa.de.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Höss
mesh_terms: D000818:Animals; D001682:Biological Availability; D017173:Caenorhabditis elegans / Q000187:drug effects*; D002606:Charcoal / Q000737:chemistry*; D000076282:Composting; D011721:Pyrenes / Q000633:toxicity*; D012098:Reproduction / Q000187:drug effects; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D011721:Pyrenes; D012987:Soil; D012989:Soil Pollutants; C540010:biochar; D002606:Charcoal
keywords: Biochar; Compost; Nematodes; Pyrene toxicity; Solid-phase microextraction; Sorption