Science Inventory

Prediction of Population Exposures to Chemicals in the Indoor Residential Environment

Citation:

Isaacs, K. Prediction of Population Exposures to Chemicals in the Indoor Residential Environment. Society of Toxicology Virtual 2021 Annual Meeting, Virtual, NC, March 12 - 26, 2021. https://doi.org/10.23645/epacomptox.17130086

Impact/Purpose:

This presentation is an invited talk for a Society of Toxicology March 2021 conference session titled "It is Not Just Air; Exposure to Indoor Air Pollution, Evaluation of Health Effects and Diagnostic Tools"

Description:

The emissions of chemicals from indoor, or “near-field”, sources such building materials and household articles contribute significantly to human exposure. These chemicals may include plasticizers (e.g., phthalates), flame retardants, synthetic fragrances, environmental phenols, and other volatile or semivolatile compounds. Many of these chemicals have been investigated for association with various health endpoints including endocrine disruption and asthma. Unfortunately, existing sources of hazard and exposure data do not directly address many thousands of chemicals that may be present in the indoor environment or used in commerce. This talk will focus on high-throughput methods being developed by the EPA Office of Research and Development to characterize human near-field exposures to these chemicals. Models and analytical approaches are being developed to address critical gaps in relevant information required to predict chemical occurrence, emission, fate, and ultimately human exposure in indoor environments. Informatic methods are being used to extract reported chemical ingredient information from thousands of public documents (e.g., SDS sheets, ingredient list, manufacturer disclosures) while new non-targeted analytical methods are being used to screen for thousands of unreported chemicals in consumer products. These data are being integrated with product sales information for U.S. households to identify critical co-exposures having common endpoints (e.g., endocrine disruption) that may ultimately increase risk. In addition, new structure-based models are being developed to predict critical parameters for estimating chemical emission from consumer articles used indoors. Finally, the talk will cover the development of population-based screening-level and mid-tier models for predicting indoor fate and transport of chemicals to air and dust and the exposures that result from human contact with these media. The high-throughput exposure estimates generated via these methods can be integrated with in vitro hazard information (assay results or models for bioactivity) to develop screen-level metrics of risk. Overall, these high-throughput methods will allow the identification and further testing of those chemicals which are more likely to pose a risk to humans.