Toxicity Characterization of Complex Mixtures Using Biological and Chemical Analysis in Preparation for Assessment of Mixture Similarity

• Published in: Environmental science & technology Vol. 38; no. 19; pp. 5127 - 5133
• Main Authors: Cizmas, Leslie, McDonald, Thomas J, Phillips, Tracie D, Gillespie, Annika M, Lingenfelter, Rebecca A, Kubena, Leon F, Phillips, Timothy D, Donnelly, Kirby C
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-10-2004
• Subjects: Analytical chemistry; Animal, plant and microbial ecology; Applied ecology; Bioassays; Biochemistry; Biological and medical sciences; Biological Assay; DNA Damage; Drug Interactions; Ecotoxicology, biological effects of pollution; Environmental Pollutants - toxicity; Escherichia coli; Escherichia coli - genetics; Fundamental and applied biological sciences. Psychology; General aspects; Hazardous materials; Pentachlorophenol - toxicity; Polycyclic Aromatic Hydrocarbons - toxicity; Risk Assessment; Salmonella; Salmonella - genetics; Toxicity; Toxicity Tests - methods; USA; Salmonella; Chemical analysis; Bioassay; Hydrocarbon; Toxicity; Escherichia coli; Genotoxicity; Risk analysis; Polycyclic aromatic compound; Microsome; Screening test; In vitro; Toxic association; Wood waste; Characterization; Gas chromatography; Bacteria; Pentachlorophenol; Mass spectrometry; Organic compounds; Enterobacteriaceae
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es035287p

In the United States, several proposed approaches for using bioassays for the risk assessment of complex hazardous mixtures require that selected mixtures be “sufficiently similar” to each other. The goal of this research was to evaluate the utility of a protocol using in vitro bioassays and chemical analysis as a basis for assessing mixture similarity. Two wood preserving wastes (WPWs) containing polycyclic aromatic hydrocarbons and pentachlorophenol were extracted and fractionated to generate potentially similar mixtures. Chemical analysis was conducted using gas chromatography/mass spectrometry. Genotoxicity was evaluated using the Salmonella/microsome and Escherichia coli prophage induction assays. The crude extract of one WPW was also tested in the chick embryotoxicity screening test (CHEST) assay. The CHEST assay provided the most sensitive measurement of toxicity. Overall, the biological potency of the samples was not well correlated with predicted potency based on chemical analysis. Although several mixtures appeared similar based on chemical analysis, the magnitude of the response in bioassays was often dissimilar. Fractionation was required to detect the genotoxicity of mixture components in vitro. The results confirm the need for an integrated protocol, combining chemical analysis, fractionation, and biological testing to characterize the risk associated with complex mixtures.