Short-Term Impacts of PM_2.5 Components on Schizophrenia Hospitalization: A Time-Series Analysis From Nanning, China

Schizophrenia (SCZ) is a serious psychiatric condition. While PM_2.5 exposure has been linked to SCZ, the specific effects of its components remain poorly understood. This study aimed to explore the relationships between PM_2.5 constituents (including BC: black carbon, OM: organic matter, SO₄ ^2-: sulfate, NH₄ ⁺: ammonium, and NO₃ ^-: nitrate) and SCZ. It incorporated the hospitalization records of 16,082 SCZ patients from Nanning Fifth People's Hospital, spanning from 1 January 2014, to 31 December 2023. The daily concentration data of PM_2.5 and its five chemical components were sourced from Tracking Air Pollution in China (TAP). A distributed lag nonlinear model (DLNM) was employed to measure the dynamic correlation between PM_2.5 components and the risk of hospitalization for SCZ. Further analysis was conducted by stratifying based on gender, age, and cold/warm seasons to identify susceptible populations. Our study revealed that OM and BC demonstrated lagged effects on SCZ hospitalization, with significant associations observed at lag 3 day(lag3)and lag4. The strongest effect was identified at lag4, with OM showing an relative risks (RR) of 1.010 (95%CI: 1.001, 1.019) and BC exhibiting a higher RR of 1.010 (1.001, 1.019). And the lag effect of the OM relative percentage was identified at lag 3 (RR = 1.013, 95% CI: 1.005-1.022). PM_2.5, SO₄ ^2-, and NH₄ ⁺ showed lagged response trends but no statistically significant effects (p > 0.05). Subgroup analysis indicated that males, 45 years and younger, and those exposed during the warm season had higher risks associated with SO₄ ^2-, OM, BC, and PM_2.5. Short-term exposure to OM is significantly related to SCZ hospitalization.