The Ionic Component of PM2.5 May Be Associated with Respiratory Symptoms and Peak Expiratory Flow Rate

Abstract

(1) Background: Few studies have evaluated the association between the ionic components of PM2.5 and respiratory symptoms or peak expiratory flow rate (PEFR). The aim of this study was to clarify these associations. (2) Methods: Patients with allergic diseases treated at Fukuoka Hospital recorded their morning and evening PEFR and respiratory symptoms in a diary. We measured PM2.5 and its ionic components in Fukuoka City and examined the relationship with PEFR and respiratory symptoms by univariate and multivariate analysis. (3) Results: Among the ionic components of PM2.5, Cl−, NO3−, Na+, K+, and Mg2+ were significantly correlated with the frequency of coughing and nasal symptoms. In univariate analysis, the concentrations of each of the above ions was significantly associated with a decrease in PEFR and the concentrations of each was associated with at least one respiratory symptom or PEFR. Multivariate analysis of items significantly correlated with PEFR indicated that the concentration of ionic components may predict changes in PEFR. (4) Conclusions: In patients with allergic diseases, some ionic components of PM2.5 may increase the frequency of respiratory symptoms and decrease PEFR, so further study and caution are required in daily clinical practice.