Short-term PM1 Exposure and Sleep Duration: A Nationwide Study Using Consumer-grade Wearable Devices

Insufficient sleep is a growing global health concern, linked to various adverse health outcomes. While the effects of PM2.5 on health are well-documented, the impact of PM1 exposure, particularly its interaction effects with temperature on sleep quality, remains less understood. This nationwide study included 1,100,294 records from 4,783 individuals nationwide using wearable devices to collect sleep data. Daily PM1 exposure levels were derived from the China High Air Pollutants (CHAP) dataset, and hourly nighttime temperatures were obtained from the ERA5-Land dataset. Associations between PM1 exposure and sleep duration were evaluated using linear mixed-effect models. An interquartile range (IQR) increase in PM1 concentration significantly altered sleep duration: total sleep increased by 1.51 minutes (95% CI: 0.52 to 2.50), light sleep increased by 2.87 minutes (95% CI: 1.97 to 3.76), and deep sleep decreased by 1.28 minutes (95% CI: -1.81 to -0.75). Nighttime temperatures were negatively associated with sleep duration. High nighttime temperatures amplified the adverse impact of PM1 on deep sleep reduction, while slightly mitigating its effect on light sleep. Stronger associations were observed in individuals aged 45 years and older, those with lower BMI, urban residents, and daily smokers. These findings demonstrated that short-term PM1 exposure disrupts sleep structure by increasing light sleep duration and reducing deep sleep duration, with elevated nighttime temperatures exacerbating these effects. Our research emphasizes the need for strategies to maintain optimal nighttime temperatures and reduce PM1 emissions, particularly safeguarding sleep quality in vulnerable populations, including older adults, individuals with lower BMI, urban dwellers, and smokers.