PM_2.5-Bound Organophosphate Esters and Childhood Sleep Disorders: Evidence from the Pearl River Delta Study

Although particulate matter has been associated with sleep problems, the effects of PM_2.5-bound organophosphate esters (OPEs) on children’s sleep remain unclear. In this study, we examined the relationship between OPEs in PM_2.5 and sleep disorders in children. This cross-sectional study included 110,169 children aged 6–18 years from primary and secondary schools in the Pearl River Delta (PRD), China. Sleep disorders were evaluated using the validated Sleep Disturbance Scale for Children (SDSC). Concentrations of OPEs were measured through school-based sampling and chemical analysis. Elastic net regression identified key OPE exposures, binomial generalized linear mixed models estimated individual OPE effects with the city as a random effect, and weighted quantile sum regression assessed the combined effects of OPE mixtures. All odds ratios indicate the change in likelihood of sleep disorders per interquartile range (IQR) increase in OPE concentrations. Although all components showed significant associations, the highest odds were observed with TDCIPP for short sleep duration (OR: 1.56–1.61), TEHP for short sleep duration (OR: 1.59–1.64), and TPHP for overall sleep disorder (OR: 1.32–1.42). Combine OPE exposure was positively associated with all childhood sleep disorders, with odds ratios ranging from 2.02 to 2.85 across various sleep outcomes. These findings highlight how OPE mixtures in PM_2.5 affect child sleep health, emphasizing the need for comprehensive analytical methods.