#AI reads Urine# Ingestion of Surface Residues Dominates Quaternary Ammonium Compounds (QACs) Exposure in Chinese Urban Homes: Evidence from Silicone Wristband Passive Sampling and Urinary Biomonitoring
Published 14 April, 2026
This study recruited 109 adult participants from urban households in southern China, collecting paired samples of indoor dust, bulk air, hand wipes, silicone wristbands, and urine. By using liquid chromatography-mass spectrometry techniques, it identified seven hydroxylated and carboxylated metabolites of benzylalkyldimethylammonium compounds (BACs) as urinary biomarkers. Subsequent tests revealed the ubiquitous presence of 23 quaternary ammonium compounds (QACs) in various environmental matrices, with a significant positive correlation observed between the QAC concentrations in silicone wristbands and those in dust, bulk air, and hand wipes (r = 0.564, p < 0.01). Additionally, the parent C10- and C12-BACs detected in wristbands showed a strong correlation with their corresponding metabolites in urine (r = 0.481–0.607, p < 0.01). Back-calculations based on urinary exposure biomarkers indicated that ingestion of surface residues was the dominant exposure route for C10-, C12-, and C14-BACs, accounting for 3.7%, 49.6%, and 18% of the total exposure respectively. The findings confirm that silicone wristbands can serve as an effective tool for assessing external QAC exposure, while urinary metabolites accurately reflect internal exposure levels. Meanwhile, the study also points out limitations such as a small sample size and the lack of fecal sample collection for analysis.
Environ Sci Technol. 2026 Jan 28. doi: 10.1021/acs.est.5c16557.
Youhe Gao
Statement: During the preparation of this work the author(s) used Doubao / AI reading for summarizing the content. After using this tool/service, the author(s) reviewed and edited the content as needed and take(s) full responsibility for the content of the published article.
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