Occurrence, composition profiles, and human exposure assessment of liquid crystal monomers in indoor dust from Wuxi, China.

Liquid crystal monomers (LCMs), widely used in liquid crystal devices, have recently attracted increasing attention due to their persistence, bioaccumulation potential, and emerging toxicological concerns. However, their occurrence and distribution in everyday indoor environments remain poorly characterized. In this study, 47 LCMs were quantified in indoor dust collected from digital stores and residential homes in Wuxi, China. LCMs were detected in all indoor samples, with total concentrations in digital store dust ranging from 15.6 to 704 ng/g (median: 60.2 ng/g), significantly higher than residential dust levels of 0.503-79.9 ng/g (median: 4.58 ng/g). In digital stores, fluorinated and non-fluorinated LCMs were negatively correlated, whereas no significant correlation was observed in residences, suggesting different sources or environmental behaviors. Exposure assessment suggested that dust ingestion and dermal contact were the dominant exposure pathways, and estimated daily intakes were higher for children than for adults. Although hazard quotients for the 15 LCMs with available toxicity benchmarks were all below unity, the lack of comprehensive toxicological reference values introduces substantial uncertainty into the risk characterization. Overall, this study identifies digital stores as important indoor hotspots for LCM contamination and highlights critical data gaps, underscoring the need for further toxicological research to support robust human health risk assessment.