Revalue associations of short-term exposure to air pollution with respiratory hospital admissions in Lanzhou, China after the control and treatment of current pollution

Significant progress has been made in air pollution control Lanzhou, China recently, however, there was only one study so far on the assessment on health gains from air quality improvement after adopting strict air pollution control measures. The present study aimed to estimate the short-term effects of six criteria air pollutants including PM2.5, PM10, NO2, SO2, CO and O-3 on respiratory admissions in Lanzhou, China, then compare the results of our study with those earlier studies conducted in Lanzhou before the implementation of air pollution control measures. Data on daily hospital admissions from the three largest hospitals in Lanzhou and daily air pollution concentration and meteorological variable were collected during a 4-year period (2014-2017). A generalized additive model; adjusted for long-term trend, seasonality, and other potential confounders was done to quantitatively assess the influences of air pollutants on daily respiratory admissions and analyze the influences of different seasons, sexes, and age groups. The most apparent effects for PM2.5, PM10, SO2, CO and O-3 on respiratory hospitalizations were observed at lag6, and lag7, respectively, and a 10 mu g/m(3) increase in PM2.5, PM10, SO2, CO and O-3 concentration were associated with 0.885% (95%CI: 0.414%similar to 1.358%), 0.328% (95%CI: 0.145%similar to 0.511%), 3.005% (95%CI: 1.689%similar to 4.339%), 3.199% (95%CI: 0.912%similar to 5.537%) for CO, 0.733% (95%Cl: 0.263%similar to 1.205%) increase in respiratory admission, respectively. No remarkable association was found between NO2 and respiratory disease hospitalisation. Females and younger groups were more susceptible to air pollutant than males and elderly groups. Together, we demonstrated that the positive associations were more pronounced in the cold season than in the warm season. The findings in present study suggest that even in Lanzhou, where air quality has been improved dramatically, positive associations still exist between air pollution and daily number of total respiratory admission.