Chemical Mixtures Core

Oregon State University, Corvallis OR

Investigators

Linked publications, trials & patents

Abstract

SUMMARY – CHEMICAL MIXTURES CORE The mission of the OSU SRC is to identify polycyclic aromatic hydrocarbons (PAHs) in the environment, to characterize their toxicity, to specify the environmental concentrations of those chemicals below which pose no threat to human health, and to find sustainable and safe solutions to remediate contaminated areas. The OSU SRC will study the composition of complex mixtures, the ways in which composition changes after remediation and natural attenuation, and the implications of PAH mixtures for human health. Superfund sites contain mixtures of many contaminants. The US EPA Supplemental Guidance for Conducting Health Risk Assessments of Chemicals states that “approaches based on whole mixtures are preferred to component approaches.” The research community needs robust, analyte-rich methods suitable for studying complex matrices. Specifically, we need new, specialized, more sensitive methods to separate, detect, and quantify dozens of PAHs and substituted PAHs with widely varying concentrations and chemical properties in complex, heterogeneous matrices. These challenges drive the development of analytical methods for PAHs, alkylated PAHs (a-PAHs) and PAH transformation products, as well as Superfund co-contaminants. It is demanding to analyze PAHs and a-PAHs in environmental and biological matrices because the samples are complex, the numerous isomers of alkylated and high-molecular-mass compounds are difficult to differentiate, and we still lack suitable standards and reference materials for many PAH metabolites. The CMC will collect mixtures of environmental chemicals at four Superfund sites which we call Complex Superfund Site Mixtures (CSSM). The research projects and the other research support core will conduct toxicity experiments with the CSSM via effects-directed analysis in a protocol that we call the Combined Superfund Site Approach (CSSA). The CMC will support the CSSA by fractionating mixtures of complex chemicals, analyzing toxic fractions to identify the components, and identifying suspect chemicals within the fractions for individual toxicity testing. The primary goal of the CMC is to support other SRC projects and cores. We will maximize their access to quality- assured quantitative analytical technologies and empower them to increase their knowledge and exercise their creativity. We will create new methods for analyzing PAHs, a-PAH, metabolites, and substituted PAHs. We will collaborate with the DMAC to improve our web-based interface for requesting standards and submitting samples. We will improve our high-volume data production and management platform. We will expand the 1,530-analyte screen by implementing novel non-target screening approaches for mixture investigation. We will create bioavailable, real-world reference materials from Superfund soil, sediment, and water extracts in collaboration with the environmental projects and provide these materials to the biological projects. We will provide web-based training material for center investigators and trainees.