Relationship of Air Pollution and Daily Hospital Admissions Due to Respiratory Disease: A Time Series Analysis

Introduction: Air pollutants and respiratory diseases have a significant relationship and cause major health problems. Low attention has been paid to the daily hospital admissions due to the presence of pollutants in desert cities such as Yazd city, Iran. Therefore, this study aimed to investigate the short-term relationship between air pollution and daily hospital admissions due to respiratory disease in Yazd hospitals. Materials and Methods: This cross-sectional study investigated pollutants including PM۱۰, CO, SO۲, NO۲, and O۳ recorded daily in Yazd air pollution monitoring station. Moreover, the daily hospital admissions (sample size =۱۸۰) of the pulmonary patients were collected from government hospitals from March to September ۲۰۱۷.  Results: The results showed that PM۱۰ concentrations were higher than the Environmental Protection Agency (EPA) and World Health Organization standards. Furthermore, only ۷.۶% of the patients' diseases were attributed to air pollution. The highest correlation (R = ۰.۵۹۵ and P = ۰.۰۰۲) was observed between daily hospital admissions and NO۲ concentration. However, after age adjustment in regression analysis, this relationship was also significant for O۳. The behavior and variations of pollutants were interpreted by time series using auto-regressive moving average (ARMA) (۱,۱). The results showed that the best correlation was found between pollutants and admission of the patients at lag = ۴۸ hr.  Conclusion: The daily admission of patients to hospital due to pulmonary disease was highly related to NO۲ and O۳. However, the correlation of admission with CO, PM۱۰, and SO۲ was not significant, because NO۲ and O۳ are oxidation factors and stimulate the respiratory system.

Keywords:

Respiratory Disease , Air Pollution , Yazd City , Particular Matter , Time-Series Analysis.