2015 Progress Report: Tracking Semivolatile Organic Compounds Indoors: Merging Models and Field Sampling to Access Concentrations, Emissions, and ExposuresEPA Grant Number: R835641
Title: Tracking Semivolatile Organic Compounds Indoors: Merging Models and Field Sampling to Access Concentrations, Emissions, and Exposures
Investigators: Bennett, Deborah H. , Young, Thomas M , Shin, Hyeong-Moo
Institution: University of California - Davis
EPA Project Officer: Klieforth, Barbara I
Project Period: September 1, 2014 through August 31, 2017 (Extended to August 31, 2018)
Project Period Covered by this Report: September 1, 2014 through August 30,2015
Project Amount: $900,000
RFA: New Methods in 21st Century Exposure Science (2013) RFA Text | Recipients Lists
Research Category: Safer Chemicals , Human Health
The goals of this project are to (1) measure concentrations of a broad spectrum of target and non-target semivolatile organic compounds (SOVCs) in indoor dust to estimate emission rates and exposures; (2) refine and evaluate a multi-compartment indoor fate, transport, and exposure model; and (3) evaluate air-to-skin transdermal uptake models.
- Selection of target compounds: A total of 85 organic chemicals were selected that were either frequently detected in dust based on literature data or had multiple listings in the Consumer Product Chemical Profiles database (CPCPdb) of U.S. EPA. The selected chemicals are spanning a broad range of the chemical space (polarity, volatility, speciation, functional groups), and from each different chemical class, indicator substances were selected. The selected chemicals were compared with another research group (Heather Stapleton, Duke University).
- Participant recruitment: We recruited about 25 participants who are planning to replace their couches, a major source of flame retardants, in the home. This will allow us to determine how much flame retardants in dust from home is reduced over the time course of enrollment (19 months) when people get a new couch or replace the foam in their couch. We anticipated that some of these participants will not follow through on their plans to obtain a new couch and thus recruited additional participants accordingly.
- Dust collection: We started collection of longitudinal dust samples from about 22 participant homes. We also collected 18 dust samples from a case-control autism study (CHARGE), in which we will measure a broad spectrum of SVOCs.
- Analytical method development: The analytical method development for the measurement of targeted and non-targeted chemicals is close to be finished and only needs to be validated.
- Dermal exposure study: A method for the dermal exposure study has been changed from analyzing chemical concentrations in surgical skin to analyzing in skin wipes.
- Indoor exposure modeling: We added exposure pathways for cleaning products with down-the-drain applications and estimated contribution of its individual exposure (i.e., during use, due to indoor release, down-the-drain) to total exposure.
- Continue collecting dust samples from the CHARGE and AIRE Studies for targeted and non-targeted analysis
- Analyze dust samples for pre-selected target compounds
- Continue collection of longitudinal dust samples from participants who are planning to replace their couches
- Finalize the development of analytical methods for non-targeted analysis in dust and for targeted analysis in hand-wipe samples
- Collect skin wipe samples
- Refine and evaluate a multi-compartment indoor fate, transport, and exposure model with field measurements
- Prepare drafts for publications in peer-reviewed journals.