Grantee Research Project Results
2021 Progress Report: An integrative approach for estimating childrens soil and dust ingestion rates
EPA Grant Number: R840209Title: An integrative approach for estimating childrens soil and dust ingestion rates
Investigators: Li, Li , Khlystov, Andrey , Li, Dingsheng , Fu, You , Son, Yeongkwon , Samburova, Vera , Liu, Yan
Institution: University of Nevada - Reno , Desert Research Institute
EPA Project Officer: Hahn, Intaek
Project Period: June 1, 2021 through May 13, 2025
Project Period Covered by this Report: June 1, 2021 through May 31,2022
Project Amount: $1,341,123
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:
This project seeks to develop an innovative integrative approach, which fuses observational, analytical, computational, and statistical methods, to estimate dust/soil ingestion rates of children aged 6 months through 6 years with demographic and environmental variabilities.
Progress Summary:
As of May 2022, we have recruited 78 children of diverse ages, genders, races/ethnicities, parental education levels, housing conditions, and other demographic backgrounds. We have made joint observational, analytical, computational, and statistical efforts to obtain and leverage the individual-specific data associated with these children. Specifically,
- Using the systematic observation approach, we have conducted structured observations of touching and mouthing activities of 78 children (observation in the cold/wet season) and 33 children (observations in both hot/dry and cold/wet seasons) in daycare centers, public parks, school playgrounds, and home backyards, during the daylight hours. The observation data were subject to stringent quality control and quality assurance. The agreement between two observers is on average 78%, considered as good to excellent in kinesiological observation practices. Once completed, this dataset will be used to develop and parameterize computational models linking children’s behavior with the rate of dust/soil ingestion.
- We have finished collecting urine and stool samples of 46 children. We have also collected 43 dust samples and 29 neighborhood soil samples; the numbers of dust and soil samples are fewer than the numbers of urine and stool samples because several children are from the same families or the same neighborhoods. We have completed analyzing the concentrations of 23 organic and inorganic biomarkers in all these samples. These concentration data will be used for estimating the rate of dust/soil ingestion.
- We have upgraded a human exposure and dosimetry model in support of quantitatively and mechanistically linking the human daily intake doses of environmental chemicals with their concentrations in blood and urine. The model succeeded in reproducing the experimentally derived total elimination half-lives of 1,100+ chemical substances (spanning 7 orders of magnitude) with a root-mean-square-derivation of merely 0.58 log units. This model allows us to back-calculate the dose of chemicals ingested by each child, and by extension, the corresponding rate of dust/soil ingestion.
- We have developed a regression-based method to “unzip” pooled measurements of chemical concentrations in biomonitoring studies. This statistical method allows the use of the data pooling strategy in this project, which may significantly reduce the cost and time associated with characterizing the specimens while retaining similar precision in statistical analysis.
This project involves human subjects. The research plan has been approved by the University of Nevada, Reno’s Institutional Review Board (IRB) on June 10, 2021, and the EPA Human Subjects Research Review Official on June 28, 2021. The IRB has maintained oversight over the research since the project started. The IRB reviewed our submitted Continuing Review/Progress Report for the first year and approved the annual renewal on July 29, 2022.
Future Activities:
In Year 2, we plan to continue recruiting and observing children from the local daycare centers, elementary schools, and neighborhoods. We will analyze biomarker concentrations in environmental (dust and soil) and biological (urine and stool) samples associated with the participating children. We will develop and evaluate a dust/soil ingestion model in support of predicting scenario-specific dust/soil ingestion rates, as envisioned in the research proposal. With the obtained observational and analytical data, we will use multivariate linear regression and structural equation modeling regression to infer children’s rates of dust/soil ingestion and investigate their association with demographic and environmental factors.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
| Other project views: | All 8 publications | 5 publications in selected types | All 5 journal articles |
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Yeh K, Li L, Wania F, Abbatt JP. Thirdhand smoke from tobacco, e-cigarettes, cannabis, methamphetamine and cocaine:Partitioning, reactive fate, and human exposure in indoor environments. Environment International 2022;160:107063. |
R840209 (2021) |
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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.