Chemical and bioanalytical characterisation
of PAH-contaminated soils
-identification, availability and mixture toxicity of AhR agonists av
Maria Larsson
Akademisk avhandling
Avhandling för filosofie doktorsexamen i kemi, som kommer att försvaras offentligt fredag den 27 september 2013 kl. 10.00, Hörsal B, Bilbergska, Örebro universitet
Opponent: professor Peter Haglund Kemiska Institutionen, Umeå universitet
Umeå
Örebro universitet
Institutionen för naturvetenskap och teknik 701 82 ÖREBRO
Abstract
Maria Larsson (2013): Chemical and bioanalytical characterisation of PAH-contaminated soils -identification, availability and mixture toxicity of AhR agonists. Örebro Studies in Chemistry 13.
Contaminated soils are a worldwide problem. Polycyclic aromatic hydro-carbons (PAHs) are common contaminants in soil at former industrial areas, especially at old gasworks sites, gas stations and former wood im-pregnation facilities. Risk assessments of PAHs in contaminated soils are usually based on chemical analysis of a small number of individual PAHs, which only constitute a small part of the complex cocktail of hundreds of PAHs and other related polycyclic aromatic compounds (PACs) in the soils. Generally, the mixture composition of PAH-contaminated soils is rarely known and the mechanisms of toxicity and interactions between the pollutants are far from fully understood.
The main objective of this thesis was to characterize remediated PAH-contaminated soils by use of a chemical and bioanalytical approach. Bio-assay specific relative potency (REP) values for 38 PAHs and related PACs were developed in the sensitive H4IIE-luc bioassay and used in mass-balance analysis of remediated PAH contaminated soils, to assess the con-tribution of chemically quantified compounds to the overall aryl hydro-carbon receptor (AhR)-mediated activity observed in the H4IIE-luc bioas-say. Mixtures studies showed additive AhR-mediated effects of PACs, including PAHs, oxy-PAHs, methylated PAHs and azaarenes, in the bioas-say, which supports the use of REP values in risk assessment. The results from the chemical and bioassay analysis showed that PAH-contaminated soils contained a large fraction of AhR activating compounds whose effect could not be explained by chemical analysis of the 16 priority PAHs. Fur-ther chemical identification and biological studies are necessary to determine whether these unknown substances pose a risk to human health or the envi-ronment. Results presented in this thesis are an important step in the devel-opment of AhR-based bioassay analysis and risk assessment of complex PAH-contaminated samples.
Keywords: Polycyclic aromatic compounds; Soil; Risk assessment; Mixture
studies; AhR-mediated activity; REPs; GC/MS; H4IIE-luc bioassay.
Maria Larsson, School of Science and Technology, Örebro University, SE-701 82 Örebro, Sweden, maria.larsson@oru.se
