Rapid Chemical Assessments Using Open Computational Models

New chemical assessments methods provide a mechanism for meeting the expectation that an assessment will include the available and relevant information for chemical hazard identification. The challenge is that while some chemicals are data rich, others have limited to no available data. Assessment workflows can be applied to transparently and objectively explore and summarize the available chemical information. These methods combine subject matter experts, domain knowledge, and computational tools allowing for smarter use of expert time. This introduction will bring participants up to speed on chemical assessment workflows and their information needs highlighting where rapid risk assessment fits in. A brief description on tools for information provenance, accessibility and usability will be overviewed in fit-for-purpose assessment workflow to set the stage for the subsequent presentations.

Impact/Purpose

This presentation provides the introductory content to a continuing education course at SOT2021 annual meeting. Course Description: Traditional chemical assessments are time intensive manual efforts requiring large amounts of human and experimental data. There are times though when a quick assessment of health impacts for a chemical is needed. Literature-based chemical assessments paired with computational and open access (free) software applications (tools) can provide a quick, evidence-based solution. Human expertise supported by these tools can allow you to go from zero information to a preliminary hazard level without setting foot in the lab. Many freely available tools and workflows exist to support this process without adding on the cost for new software. In this course we will provide an overview of the types of chemical health safety assessments and their information requirements, setting the stage for how tools can support rapid chemical evaluations. It will close with an example of how structured data extractions are deposited into EPA dashboards. The format of the course follows the risk assessment process as follows: • Identifying chemical information using literature search: No/little information on a chemical? Learn how to conduct a literature search for chemical data. Focus will be on search stratagy, identifying studies with information of interest, and results prioritization. • Expanding the dataset using chemcial similarity: Are the data for the chemical of interest limited, but rich for a structurally similar neighbor? Learn how to expand your chemical search for data poor chemicals using structural similarity or apply new approach methods in chemical assessment while considering other key data. • Using in vitro evidence for toxicokinetic modeling: Is the evidence so limited (i.e. no information available at all) that a purely in vitro/in silico approach should be considered? Learn how to use in vitro to in vivo extrapolation to calculate in vivo measurements- even ones tailored to susceptible populations. This will help you go from internal concentrations (or close estimates) to external/applied exposure concentrations/doses. • Calculation of point of departure: Use the concentration response information from various data sources, including in vitro, in vivo, and in silico, to develop the point of departure (POD). You’ll need the POD to develop toxicity reference values that you can use to estimate safe exposure levels. Course materials will include listing of additional resources, a walkthrough of highlighted tools discussed, and example datasets. At the end of this course, participants will be able to: • Explore and prioritize data needed for rapid chemical assessment • Expand searches for data poor chemicals using chemical analog toxicity information • Extrapolate in vitro bioactivity to in vivo exposure scenarios • Apply approaches for calculating POD

Citation

Angrish, M. Rapid Chemical Assessments Using Open Computational Models. Society of Toxicology Annual Meeting 2021, Virtually, March 12 - 19, 2021.

• SOT CE INTRO MA.PPTX