Food Safety and Environmental Stewardship Program

BRIDGES is a bioanalytical tool that combines passive sampling with the embryonic zebrafish developmental toxicity bioassay to provide a quantitative measure of the toxicity of bioavailable complex mixtures. Passive sampling devices (PSDs), which sequester and concentrate bioavailable organic contaminants from the environment, were deployed in the Willamette and Columbia Rivers within and outside of the Portland Harbor Superfund site in Portland, Oregon. Six sampling events were conducted in the summer and fall of 2009 and 2010. PSD extracts were analyzed for PAH compounds and screened for 1,200 chemicals of concern using deconvolution reporting software. The developmental toxicity of the extracts was analyzed using the embryonic zebrafish bioassay. Significant spatial and temporal differences in the concentration of contaminants at the sites were observed. Similarly, significant differences in the developmental toxicity of the samples were recorded. This demonstrates the importance of utilizing an environmental monitoring tool, such as BRIDGES, that can provide site-specific, temporally resolved information about environmental contaminants and directly link environmental samples to toxicity. Multivariate modeling approaches were applied to paired chemical-toxic effects data sets to help unravel chemistry-toxicity associations. Although this research highlights the complexity of discerning specific bioactive compounds in complex mixtures, it demonstrates methods for associating toxic effects with chemical characteristics of environmental samples.