Greater impacts of air pollution from mobile source on morbidity of pneumonia and influenza-A tri-city study in Taiwan

Greater risk for cardiopulmonary diseases resulted from pneumonia and influenza (P&I) infection and/or air pollution has been observed in many studies. But, there are limited investigations focusing on the interaction between atmospheric condition and airway infections. This study analyzed the association between clinic visits of P&I and ambient atmosphere condition by Poisson regression in three major metropolitans (Taipei, Taichung and Kaohsiung) in Taiwan. Prevalence of P&I is the lowest in the capital of Taiwan (Taipei) and the highest in the city of petrochemical industries (Kaohsiung). In studying the association between atmospheric environment and the clinic visit rates of P&I, we observed a greater health impact of ambient temperature in Taipei than in Kaohsiung. When air pollutants were included in the multivariate model, significant risk for the infection associated with nitrogen oxides (NOx) was especially noted in the 3 metropolitans. The relative risks of pneumonia and influenza for 1 ppb increase of NOx were1.004 (95% CI: 1.001-1.007) in Taipei, 1.005 (95% CI: 1.002-1.008) in Taichung and 1.011 (95% CI: 1.007-1.015) in Kaohsiung. The risk for P&I morbidity associated with 1 microgram per cubic meter increase of PM10 was also significant (RR=1.003, 95% CI: 1.002-1.004) in Taipei. These findings show that the air pollution from mobile source not only has impact on P&I infection but also has an indirect association with cardiopulmonary diseases, and the relative importance of these risks need further study.