title: Photodegradation of polycyclic aromatic hydrocarbons in soils under a climate change base scenario.
abstract: The photodegradation of polycyclic aromatic hydrocarbons (PAHs) in two typical Mediterranean soils, either coarse- or fine-textured, was here investigated. Soil samples, spiked with the 16 US EPA priority PAHs, were incubated in a climate chamber at stable conditions of temperature (20 °C) and light (9.6 W m(-2)) for 28 days, simulating a climate change base scenario. PAH concentrations in soils were analyzed throughout the experiment, and correlated with data obtained by means of Microtox(®) ecotoxicity test. Photodegradation was found to be dependent on exposure time, molecular weight of each hydrocarbon, and soil texture. Fine-textured soil was able to enhance sorption, being PAHs more photodegraded than in coarse-textured soil. According to the EC50 values reported by Microtox(®), a higher detoxification was observed in fine-textured soil, being correlated with the outcomes of the analytical study. Significant photodegradation rates were detected for a number of PAHs, namely phenanthrene, anthracene, benzo(a)pyrene, and indeno(123-cd)pyrene. Benzo(a)pyrene, commonly used as an indicator for PAH pollution, was completely removed after 7 days of light exposure. In addition to the PAH chemical analysis and the ecotoxicity tests, a hydrogen isotope analysis of benzo(a)pyrene was also carried out. The degradation of this specific compound was associated to a high enrichment in (2)H, obtaining a maximum δ(2)H isotopic shift of +232‰. This strong isotopic effect observed in benzo(a)pyrene suggests that compound-specific isotope analysis (CSIA) may be a powerful tool to monitor in situ degradation of PAHs. Moreover, hydrogen isotopes of benzo(a)pyrene evidenced a degradation process of unknown origin occurring in the darkness.
authors: Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia, Spain; Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain.
authors: Montse
authors: M
authors: Marquès
authors: Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia, Spain; Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain.
authors: Montse
authors: M
authors: Mari
authors: Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Cristal·lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, SIMGEO UB-CSIC, Universitat de Barcelona UB, Martí Franquès s/n, 08028 Barcelona, Spain.
authors: Carme
authors: C
authors: Audí-Miró
authors: Environmental Engineering Laboratory, Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain; Laboratory of Soil Science, Faculty of Pharmacy, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Catalonia, Spain.
authors: Jordi
authors: J
authors: Sierra
authors: Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Cristal·lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, SIMGEO UB-CSIC, Universitat de Barcelona UB, Martí Franquès s/n, 08028 Barcelona, Spain.
authors: Albert
authors: A
authors: Soler
authors: Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia, Spain. Electronic address: marti.nadal@urv.cat.
authors: Martí
authors: M
authors: Nadal
authors: Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV, Universitat Rovira i Virgili, Sant Llorenç 21, 43201 Reus, Catalonia, Spain.
authors: José L
authors: JL
authors: Domingo
mesh_terms: D057231:Climate Change; D003903:Deuterium / Q000032:analysis; D010782:Photolysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000528:radiation effects* / Q000633:toxicity; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis / Q000528:radiation effects* / Q000633:toxicity; D018675:Toxicity Tests
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D003903:Deuterium
keywords: Ecotoxicity; Hydrogen isotopes; Photodegradation; Polycyclic aromatic hydrocarbons (PAHs); Soil