Exposure Data Quality Issues and TSCA Assessments

Abstract

EPA’s Federal Register Notice on Procedures for Chemical Risk Evaluation under the Amended Toxic Substances Control Act includes several references to the use of quality assessments for evaluating information and inclusion of quality assessments in systematic reviews. The Notice also points to the importance of using predefined criteria for assessing quality. However, rapid technological advances are producing exposure data for which there are no available data quality assessment tools. While various fields have developed approaches to rigorously and transparently assessing data quality, there is as yet no holistic approach for assessing both measured and modeled data in the context of a fit-for-purpose assessment. Using key elements from existing approaches to assessing exposure data quality, we developed an instrument - ExpoQual - for evaluating the quality of human exposure data that is applicable to both traditional sources of exposure data (the focus here is primarily quantitative measured and modeled data) as well as newer and developing approaches and includes fit-for-purpose considerations. The key strength of ExpoQual is that it facilitates a structured, reproducible and transparent approach to exposure data quality evaluation and forces an explicit determination with regards to fit-for-purpose. The instrument is agnostic regarding whether error introduced by quality issues is systematic (biased in a particular direction) or random and the framework construct does not include data rejection. ExpoQual is designed for development into an online tool; early uses with case studies and feedback from the exposure community will result in an iterative process of instrument advancement. In this presentation we describe the ExpoQual instrument and a case study testing the efficacy of the instrument.