Association between ambient PM(2.5) and emergency department visits for psychiatric emergency diseases()

BACKGROUND: Whether or not short-term exposure to particulate matter <2.5 μm in diameter (PM(2.5)) increases the risk of psychiatric emergency diseases is unclear. METHODS: The study was performed in a metropolis from January 2015 to December 2016. The exposure was PM(2.5), and the confounders were weather (temperature and humidity) and other pollutants (PM(10), SO(2), CO, O(3), and NO(2)). The outcomes were emergency department (ED) visits with psychiatric disease codes (F00-F99 in ICD10 codes). General additive models were used for the statistical analysis to calculate the adjusted relative risks (ARRs) and 95% confidence intervals (95% CIs) for the daily number of ED visits with a lag of 1 to 3 days following a 10 μg/m(3) increase in PM(2.5). RESULTS: During the study period, a total of 67,561 ED visits for psychiatric diseases were identified and tested for association with PM(2.5). Daily ED visits for all psychiatric diseases were not associated with PM(2.5) in the model that was not adjusted for other pollutants. The ARR (95% CI) in the model adjusted for SO(2) was 1.011 (1.002–1.021) by 10 μg/m(3) of PM(2.5) on Lag 1 for all psychiatric diseases (F00-F99). The ARR (95% CI) in the model adjusted for O(3) was 1.015 (1.003–1.029) by 10 μg/m(3) of PM(2.5) on Lag 1 for F40-F49 (Neurotic, stress-related and somatoform disorders). CONCLUSION: An increase in PM(2.5) showed a significant association with an increase in ED visits for all psychiatric diseases (F00-F99) and for neurotic, stress-related and somatoform disorders (F40-F49) on lag day 1.