The impact of ambient PM2.5 on daily outpatient visits due to chronic obstructive pulmonary disease, among the urban residents of Ningbo city / 中华流行病学杂志

ABSTRACT

Objective@#To explore the short-term effects of ambient PM2.5 on the outpatient visits of chronic obstructive pulmonary disease (COPD) in Ningbo city.@*Methods@#Through the regional health information platform, number of daily COPD outpatients from the four general hospitals in Ningbo was gathered. Related data on meteorological and air pollution from 2014 to 2016 was also collected. Generalized additive model (GAM) of Possion regression was used to estimate the impact of PM2.5 pollution on COPD outpatients and the lagging effects.@*Results@#In cold (November- April) or warm seasons (May-October), an 10 μg/m3 increase of PM2.5 would result in the excessive number of COPD outpatients as 1.87% (95%CI 0.98%-2.76%), 2.09% (95%CI 1.11%-3.08%) and 2.56% (95%CI 0.56%-4.59%), respectively. In terms of the short-term effects of PM2.5 the strongest was seen in the days of warm season but without delay (P<0.05). The strongest effect appeared at day 4 in cold season and the effect was particularly significant seen in the over 65 year-old group or in the female population. After the introduction of PM10, SO2 and NO2, the concentration of PM2.5, did not show significant effect on the number of hospital visits due to COPD on the same day (P>0.05). The effect of COPD on the fourth day showed a slight change after the lagging, and the effect was statistically significant (P<0.05).@*Conclusion@#The increase of PM2.5 concentration in Ningbo was related to the increase of COPD outpatient numbers. Effective prevention measures should be taken to protect the vulnerable population and to reduce the risk of COPD.