Identification of potentially toxic compounds in complex extracts of environmental samples using gas chromatography‐mass spectrometry and multivariate data analysis

Abstract

In this study, we examined 31 samples of varying chemical composition, including samples of soils from gasworks, coke production sites, and sites where wood preservatives were heavily used; ash and soot from municipal solid waste incinerators; antiskid sand; and dust from areas with heavy road traffic. The samples were comprehensively chemically characterized, especially their polycyclic aromatic compound contents, using gas chromatography-time-of-flight mass spectrometry, whereas their biological effects were assessed using dehydrogenase activity, root growth (Hordeum vulgare), reproduction of springtails (Folsomia candida), algal growth (Desmodesmus subspicatus), germinability (Sinapis alba), Vibrio fischeri, DR-CALUX, and Ames Salmonella assays. The number of compounds detected in the samples ranged from 123 to 527. Using the multivariate regression technique of partial-least-squares projections to latent structures, it was possible to find individual compounds that exhibited strong correlations with the different biological responses. Some of the results, however, indicate that a broader chemical characterization may be needed to identify all the compounds that may cause the measured biological responses.

AhR agonist and genotoxicant bioavailability in a PAH-contaminated soil undergoing biological treatment

“…It is well known that the AhR is activated by a large array of diverse chemical structures . The results from the fullscan analysis support the assumption that PAH16 probably only contributed a small fraction of all organic compounds in the soil samples, which is in line with a study performed by Bergknut et al (2007) who identified hundreds of peaks in contaminated soil samples and concluded that unidentified substances contributed to effects observed in various biological test systems. These compounds probably include a wide range of PAHs besides PAH16, for example heterocyclic PAHs and oxy-PAHs, which have all been identified in soil from old gas work sites (Lundstedt et al 2003).…”

Identifying Toxicologically Significant Compounds in Urban Wildfire Ash Using In Vitro Bioassays and High-Resolution Mass Spectrometry

“…Dioxin-like activity of chemicals is mediated by the aryl hydrocarbon (dioxin) receptor (AhR), a nuclear receptor which binds dioxins and related chemicals with high affinity and stimulates the expressions of a battery of genes, including cytochrome P4501A1 (CYP1A1) . Recombinant cell lines containing an AhR-responsive firefly luciferase reporter gene have been extensively utilized as a simple and sensitive bioassay for the detection and relative quantitation of dioxin-like chemicals, PAHs, and related AhR activators in diverse environmental extracts, including ash. − Similarly, the ability of environmental chemicals to modulate the activity of estrogen and androgen receptors (ER and AR, respectively), nuclear receptors that play a key role in regulating the expression of genes important in reproductive and other biological effects, have been linked to a variety of adverse endocrine disruption effects. ,, Recombinant cell lines containing ER- or AR-responsive luciferase reporter genes have been developed and utilized for the detection of activators and inhibitors of these receptor signaling pathways in the extracts of environmental matrices, including atmospheric particulate materials, and environmental contaminants such as PAHs. ,− AhR-, ER-, and AR-responsive cell lines were used to assess the ability of wildfire extracts to produce estrogenic, androgenic, and dioxin-like activities. A bioassay consisting of human U937-derived macrophages was used to test the potential activity of wildfire samples to induce inflammatory biomarkers which are relevant factors in mediating human health effects including lung injuries and cardiovascular diseases.…”