Air pollutants and the admission rate of psychiatric patients

The authors studied the correlation between mean daily levels of several air pollutants and the number of emergency room visits and inpatient admissions to a psychiatric hospital in St. Louis during one summer and fall. Nitrogen dioxide and carbon monoxide showed a positive correlation with emergency room visits by all patients, and nitrogen dioxide also had a positive correlation with inpatient admissions of subjects with diagnoses that were unknown or could not be specified as psychotic. Nitrogen monoxide showed a negative correlation with inpatient admissions during working days (but not during weekends and holidays) for all patients, as well as for those with diagnoses that were unknown or could not be specified as psychotic.