The aim of the study was to investigate the unknown effect of air pollutants on the occurrence or deterioration of respiratory diseases in the area with a humid continental climate. This retrospective study included 5868 patients with respiratory symptomatology (upper respiratory tract infection (URTI), pneumonia, acute bronchitis, chronic obstructive pulmonary disease (COPD), and asthma) admitted to emergency department (ED). The number of patients, values of meteorological parameters (mean daily values of air temperature pressure and relative humidity) and concentrations of air pollution particles (