Research Project 3

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The AESOP Study: Airborne Exposures to Semi-volatile Organic Pollutants

The AESOP Study is a prospective human cohort study that is the first to comprehensively assess the PCB exposome for school children and their mothers through direct measurement of the PCBs they breathe at school and at home and in the food they eat. The AESOP Study has biobanked 10 years of samples that provide an incredible resource for analysis of biomarkers of exposure and effect. Since 2008 we have measured PCBs in the air of participants' homes, schools and outdoor environments and collected blood and measured PCBs and PCB metabolites in their serum. We expect to show that both inhalation and diet contribute to exposures to specific PCBs that are associated with elevated risks for oxidative stress, inflammation, hormone disruption and metabolic syndrome by:

1) Collecting and analyzing demographic, residential, occupational, activity, dietary and health data from AESOP Study participants

The AESOP Study will engage with three communities in the next cycle. In each community we will study a cohort of adolescent children and their mothers. The cohorts in East Chicago, IN and Columbus Junction, IA have participated for over a decade and have provided questionnaire data as well as thousands of air, blood, DNA and urine samples. We will report study results to participants in both communities and will establish a new cohort in West Liberty,IA.

 

2) Characterizing the personal exposures to PCB congeners among children and their mothers and apportion exposures to inhalation and diet at the congener level.

We will apply an innovative approach to assess our cohort participants’ personal exposures to PCBs through inhalation and diet. We will quantify inhalation exposure from measurements of airborne PCBs in homes, classrooms and outdoors. In addition, we will use DHQ-II data and congener-specific analysis of a representative food basket to assess dietary exposure. Blood and urine samples will be analyzed for biomarkers of thyroid hormone dysfunction, inflammation, and metabolic syndrome. We will report personal exposure data to our study participants and aggregated data to school officials on a regular basis.

 

3) Assessing adolescent children’s time-integrated personal exposure to airborne PCBs.

We will design a novel wearable personal sampler made from electrospun nanofiber media (ENM) to measure time-integrated inhalation exposure to airborne PCB congeners. Exposure assessments based on the ENM samplers will be compared at the congener-specific level with assessments from area samplers placed in multiple locations that the children occupy at home, in school, and outdoors.

4) Modeling PCB congener exposures and body burdens and compare modeled and measured data

We will design and test a predictive model to apportion exposures of children to PCBs and determine the uptake and loss of those congeners in humans. We will establish pharmacokinetic and dose-simulation models using computational tools such as R-linked GNU MCSim, PK-Sim®, MoBi® and SHEDS making full use of our comprehensive exposure data and absorption, distribution, metabolism and excretion from our inhalation toxicology studies completed in the current cycle. Working with the Data Management and Analysis Core, we will perform probabilistic risk analysis to characterize risk and uncertainty of inhaled PCBs in schools.

2020 Progress:

The AESOP Study has had to put a hold on recruitment and enrollment of new participants in the current grant period due to the COVID-19 pandemic. The AESOP Study team has instead focused its efforts on five major activities that relate primarily to Aims 1 and 2:

  • Organizing, cataloguing and archiving all subject data forms and questionnaires including consent forms, assent forms, home visit forms, cash payment receipts, activity logs, and questionnaires for demographics, dietary history, local fish consumption, and occupational history.
  • Re-inventorying and re-organizing 5200 serum samples, 5500 erythrocyte fraction samples, 200 whole blood samples, 400 urine samples, 4200 air samples, and 450 surficial and core soil samples.
  • Report back of exposure data to our participants and aggregated data to the community.
  • Analysis and publication of AESOP Study data and comparable NHANES data.
  • Recruitment of a new community school district for study in this new grant cycle. We have compiled data on the dates of construction, renovation and additions for 30 schools we are considering for working in when we can resume participant contact.

We plan to resume in-person contact with AESOP Study participants as soon as it is safe to do so.

Recent Publications:

Ezazul Haque, Margaret E. Moran, Peter S. Thorne,, Retrospective blood lead assessment from archived clotted erythrocyte fraction in a cohort of lead-exposed mother-child dyads(link is external), Science of The Total Environment Volume 754, 1 February 2021, 142166, PMC7686297 [Project 3]

Panithi Saktrakulkla, Tuo Lan, Jason Hua, Rachel F. Marek, Peter S. Thorne,*and Keri C. Hornbuckle*, Polychlorinated Biphenyls in Food, (link is external)Environ. Sci. Technol. 2020, 54, 18, 11443–11452. PMC7759298 [Project 3, Analytical Core]

Wang, Hui; Adamcakova-Dodd, Andrea; Flor, Susanne; Gosse, Laura; Klenov, Violet; Stolwijk, Jeffrey; Lehmler, Hans-Joachim; Hornbuckle, Keri; Ludewig, Gabriele; Robertson, Larry; Thorne, Peter. Comprehensive Subchronic Inhalation Toxicity Assessment of an Indoor School Air Mixture of PCBs.(link is external) Environ. Sci. Technol. 2020, 54, 24, 15976–15985, PMID: 33256405 [Project 3, Project 1, Project 4, Analytical Core]

Dataset

 Saktrakulkla, P.; Lan, T.; Hua, J.; Marek, R.F.; Thorne, P.S.; and Hornbuckle, K.C. “Dataset for PCBs in Food” (dataset) 2020 Iowa Research Online. https://doi.org/10.25820/data.001112(link is external) [Project 3 and Analytical Core]

 

Peter S. Thorne, MS, PhD, Project Leader

Dr. Thorne is Professor of Toxicology and head of the Department of Occupational and Environmental Health at the University of Iowa, College of Public Health. He is the Director of the Interdisciplinary Graduate Program in Human Toxicology and is the Assistant Director of the NIH funded Environmental Health Sciences Research Center. Thorne runs a productive research laboratory engaging his students in studies of PCB exposures and health effects, environmental risk factors for inflammatory lung diseases, bioaerosol-induced immunomodulation, the toxicity of engineered nanomaterials, and novel methods for exposure assessment and modeling.

Andres Martinez, PhD, Co-Investigator

Andres is Assistant Research Engineer at the IIHR—Hydroscience & Engineering and Adjunct Assistant Professor in Civil and Environmental Engineering. He has been engaged with ISRP and has extensive experience in analysis of PCB congeners in complex environmental matrices and has moved his research further into toxicology to apply his environmental modeling expertise to PBPK modeling. In the AESOP Study, Dr. Martinez will lead our PBPK modeling efforts in Aim 4. In collaboration with Project 4 he will develop the PCB electrospun nanofiber media personal sampler for Aim 3.

Rachel F. Marek, PhD, Co-Investigator

Rachel is an Assistant Research Scientist at IIHR Hydroscience & Engineering and has over ten years experience in the analytical chemistry of PCBs with published work concerning sampling and analysis of PCBs and hydroxylated PCBs in human blood serum, contaminated sediments, and air. She has been a member of the ISRP Analytical Core (AC) since 2007 and is a long-term collaborator with The AESOP Study. She will lead the Aim 2 effort to measure PCB congeners in food samples.