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High Throughput Assays for Exposure Science (NIEHS OHAT Staff Meeting presentation)
Citation:
Wambaugh, J. High Throughput Assays for Exposure Science (NIEHS OHAT Staff Meeting presentation). Presented at OHAT Staff Meeting, RTP, NC, May 11, 2016. https://doi.org/10.23645/epacomptox.5067685
Impact/Purpose:
This is a presentation to the NIEHS Office of Health Assessment and Translation (OHAT) staff meeting on the EPA ExpoCast contract work to perform non-targeted analyses of consumer product composition. OHAT is partnering with EPA to conduct similar analyses of women's hygiene products.
Description:
High throughput screening (HTS) data that characterize chemically induced biological activity have been generated for thousands of chemicals by the US interagency Tox21 and the US EPA ToxCast programs. In many cases there are no data available for comparing bioactivity from HTS with relevant human exposures. The EPA’s ExpoCast program is developing high-throughput approaches to generate the needed exposure estimates using existing databases and new, high-throughput measurements. The exposure pathway (i.e., the route of chemical from manufacture to human intake) significantly impacts the level of exposure. The presence, concentration, and formulation of chemicals in consumer products and articles of commerce (e.g., clothing) can therefore provide critical information for estimating risk. We have found that there are only limited data available on the chemical constituents (e.g., flame retardants, plasticizers) within most articles of commerce. Furthermore, the presence of some chemicals in otherwise well characterized products may be due to product packaging. We are analyzing sample consumer products using 2D gas chromatograph (GC) x GC Time of Flight Mass Spectrometry (GCxGCTOF/MS), which is suited for forensic investigation of chemicals in complex matrices (including toys, cleaners, and food). In parallel, we are working to create a reference library of retention times and spectral information for the entire Tox21 chemical library. In an examination of five plastic children’s toys, as many as 114 and as few as 56 chemicals were identified in each toy, with between 0 and 40 unidentified chemicals in each. Putative endocrine disrupter, Bisphenol A (BPA), was identified as present in a product marked “BPA free”. Information on chemical constituents of products, while only a prerequisite to actual exposure, provides heuristics for estimating likely human exposure pathways for thousands of chemicals.
URLs/Downloads:
DOI: High Throughput Assays for Exposure Science (NIEHS OHAT Staff Meeting presentation)
WAMBAUGH_EPA-PRODUCTDEFORMULATION-OHAT-051116-2.PDF (PDF, NA pp, 4401.136 KB, about PDF)