Optimizing use of novel chemicals to assess children’s dust ingestion rates

EPA Grant Number: R840208
Title: Optimizing use of novel chemicals to assess children’s dust ingestion rates
Investigators: Bennett, Deborah H. , Young, Thomas M , Kannan, Krunthachalam
Institution: University of California Davis , New York University
EPA Project Officer: Hahn, Intaek
Project Period: June 1, 2021 through May 31, 2024
Project Amount: $1,342,099
RFA: Estimating Childrens Soil and Dust Ingestion Rates for Exposure Science (2020) RFA Text |  Recipients Lists
Research Category: Human Health , Children's Health

Objective:

The goals of this project are to: (1) Develop an innovative method for determining dust ingestion rates using compounds found primarily in indoor dust rather than outdoor soil, (2a) Measure dust ingestion in children living in homes from four distinct geographic areas with differing SES, urban/rural/suburban classification, and racial/ethnic composition and and an additional cohort of children with autism or developmental delays, (2b) Determine the concentrations of a broad range of target and non-target compounds in house dust to improve understanding of indoor chemical exposures as a function of demographic variables, (3) Measure seasonal and age group variation in dust ingestion rates, and (4) Develop standard procedures for the dust tracer method to support its implementation by other organizations. 

Approach:

Over 80 chemicals will be measured in indoor dust, and their expected excreted forms will be measured in urine samples. Summing metabolized forms 
(mol/d) and dividing by concentrations in dust (mol/g) yields a chemical- and child-specific dust ingestion rate (g/d) estimate.  A variety of approaches to will be used to assess non-dust contributions (inhalation, food, product use) to chemical exposures to select optimal tracers for each child using both the Limiting Tracer Method and the Best Tracer Method used in determining soil ingestion rates. Measurements will be conducted for 150 children, with 40 children measured at multiple time-points. Five cohorts will be studied: 1a) a west coast suburban population cohort of 2-3 and 1b) 4-6 year olds, which will both be measured repeatedly; children age 2-3 from 2) a west coast urban Latinx population, 3) a northern rural population, and 4) a Southeast population, primarily black; and 5) children 2-5 with autism or developmental delays. 

Expected Results:

This innovative approach applies new technologies in both dust and urine analysis to determine child-specific dust ingestion rates, under an experimental design that includes multiple geographic and SES groups.  Key outcomes will be to: (i) identify a set of compounds that serve as optimal tracers of dust ingestion that can easily be applied in future monitoring, (ii) illustrate geographic and SES-based differences in childrens’ dust ingestion rates and chemical exposures, (iii) measure dust concentrations and overall chemical exposures for children in geographic and SES groups not frequently studied, and (iv) significantly improve risk assessment calculations involving dust ingestion by children.   

Supplemental Keywords:

indoor environment, exposure, organic compounds, nontarget analysis, children