Assessing Exposure to Plastic Related Chemicals in Second-Trimester Pregnancy: A Suspect Screening Approach

Given the dramatic increase in plastic production with a concurrent increase in exposure to plastic-related chemicals, we developed a suspect screening approach to assess prenatal exposure to plastic-related chemicals. Using liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-QTOF/MS), we conducted suspect screening for over 5,000 documented plastic-related chemicals from 200 pregnant participants collected during their second trimester. A total of 2159 positive-mode and 3609 negative-mode suspect chemical features were matched against our plastic chemical database, of which 1127/1530 (positive/negative) features were prioritized for targeted fragmentation analysis based on detection frequency (DF > 70%), peak area (> 5000 counts) accurate mass matching (ppm <=5 ppm). Suspect features were then annotated by MS/MS spectrum and retention time prediction. Differences in peak areas by demographic characteristics were also assessed. Among the 65 tentatively identified chemical features, three were candidates confirmed using reference standards: perfluorooctanesulfonic acid (PFAS compound), 8-hydroxyquinoline (antioxidant), and 1,3-diphenylguanidine (with multiple functions in rubber products). Notably, 62 tentatively identified chemicals were not previously reported in existing exposome databases, raising concerns about gaps in plastic chemical monitoring. In summary, our study highlights the potential of this suspect screening approach to identify and prioritize plastic chemical exposures during fetal development.