Grantee Research Project Results
2024 Progress Report: Community-Oriented Strategies to Estimate Childrens Soil and Dust Ingestion Rates and Exposure to Soil Heavy Metal and Metalloid in West Atlanta
EPA Grant Number: R840198Title: Community-Oriented Strategies to Estimate Childrens Soil and Dust Ingestion Rates and Exposure to Soil Heavy Metal and Metalloid in West Atlanta
Investigators: Saikawa, Eri , Barr, Dana Boyd
Institution: Emory University
EPA Project Officer: Hahn, Intaek
Project Period: July 1, 2021 through May 6, 2025
Project Period Covered by this Report: July 1, 2023 through June 30,2024
Project Amount: $1,345,022
RFA: Estimating Childrens Soil and Dust Ingestion Rates for Exposure Science (2020) RFA Text | Recipients Lists
Research Category: Children's Health , Endocrine Disruptors , Human Health
Objective:
The goal of this project is to effectively understand and mitigate the current and possible future soil heavy metal and metalloid (HMM) and other chemical contaminant exposure among children in West Atlanta (also known as the Westside) by better estimating children’s soil ingestion rates, using Community-Based Participatory Research (CBPR). Our threefold objectives are to: 1) map soil lead (Pb) and other known and unknown contaminant concentrations in West Atlanta; 2) quantify soil ingestion rates and exposure levels to Pb among children in specific age groups via soil, blood, and urine analyses; and 3) provide accurate and comprehensive multimedia metrics for exposure assessments.
Progress Summary:
We have made great progress to quantify soil ingestion rates, exposure estimates, and risk assessments in the Westside of Atlanta. We have continued mapping soil lead and other known contaminant concentrations in the Westside of Atlanta, which is listed on the National Priorities List. We have continued to conduct various outreach events throughout the years and found another site in Buckhead with soil lead contamination that also became a Superfund site. This past year, we participated in 12 soil Screening, Health, Outreach and Partnership (soilSHOP) events in communities and collected 113 soil samples. We share results to individual participants on the day of the event but we are at the same time working on mapping the results and plan to share them to participants in an aggregated manner.
We also started working on estimating dust and soil ingestion rates by using the EPA’s All Ages Lead Model (AALM). AALM is a biokinetic model which simulates intake, exchange, and excretion of lead in humans. The model can be used to estimate quantities of Pb in the body (e.g. blood PB concentration) following a simulated exposure period. The AALM currently recommends default exposure estimates taken from the latest versions of the EPA Exposure Factors Handbook, although there are numerous sources of limitations and uncertainty in using these default values. Improved soil and dust ingestion rates are crucial for quantifying children’s exposure. We are currently performing a variance-based sensitivity analysis of physiological and exposure parameters to the uncertainty in two outcomes of the AALM: concentration of Pb in blood and bone. A Gaussian process emulator is built based on simulations of the AALM at 4 different ages between 1 and 5 years. We focus on physiological and exposure-related parameters which have been previously shown to have greater relative effect on outcomes such as blood Pb concentration. Results of this sensitivity analysis will be used in a follow-up optimization analysis in conjunction with experimental data from this study to provide updated estimates of soil and dust ingestion rates as well as recommendations for model improvements to the AALM.
Two papers were published in this study period in GeoHealth. One paper discusses the finding of the soil lead contamination in the Westside and how community-engaged assessment was crucial in this process. The other paper discusses our finding of phytoremediation of lead-contaminated soil in the Westside. This was a project idea from a resident in the Westside and we quantified the bioavailability and how lead is taken up by plants. Over fifty students have been trained to conduct community-based research through this project. We have engaged the public in collecting soil samples to test for lead via soil Screening, Health, Outreach and Partnership (soilSHOP) events throughout years. More than 400 soil samples have been collected in Georgia and they are currently being mapped together with other variables, including race and income levels.
Future Activities:
We are recruiting participants at local community events and are working with various community leaders to raise awareness in the neighborhoods about soil lead contamination. Additional planned activities include school-based and church-based recruitments to increase the number of participants. We will focus on disseminating the results back to the residents and host meetings to make sure that the risk is appropriately communicated.
Journal Articles:
No journal articles submitted with this report: View all 10 publications for this projectSupplemental Keywords:
soil, exposure, risk, risk assessment, health effects, human health, bioavailability, vulnerability, dose-response, infants, children, heavy metals, community-basedRelevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.