Applying Nontargeted Analysis to Explore the Chemical Composition of Dust Collected in Infants' Homes

Dust ingestion is an important pathway for exposure to environmental chemicals, especially for children. However, estimating infant-specific dust ingestion rates remains challenging. One proposed approach to improve estimates is the identification of novel organic tracers. To help address this challenge, we conducted a nontargeted analysis on dust samples collected from waking and sleeping rooms in infants' homes (n = 30) in the greater Baltimore, MD region, as part of the INnovations to Generate Estimates of children's Soil/dust inTake (INGEST) Study. By leveraging publicly available data from the U.S. Environmental Protection Agency (EPA), including commercial product compositions and chemical functional uses, we showed that many compounds in dust were associated with personal care, cleaning, and consumer products. Most features were detected in both collection rooms in at least one home, but only 16.3% of features were detected in both rooms in all of the homes. Additionally, the relative abundance of features across rooms (i.e., room ratios) within and between homes varied substantially. The high intra- and interhome variability, possibly due to differences in consumer practices among inhabitants, may pose challenges with identifying and implementing an organic tracer for estimating children's dust ingestion rates and need to be rigorously characterized for any candidate.