Association between air pollution and hospital admissions for chronic respiratory disease in people aged over 65 years: a time series analysis in Ningbo, China, 2015-2017.

PURPOSE: To provide essential information of environmental triggers leading to CRD. METHODS: We investigated the short-term effects of ambient air pollutants on CRD-related hospitalizations in people aged ≥ 65 years in Ningbo. Data on 23,610 cases of CRD requiring hospitalization were collected from January 2015 to August 2017. After adjusting for temporal trends, seasonality, meteorological conditions, day of week (DOW), and public holidays, we used generalized additive Poisson distribution models to calculate the excess risks (ERs) and 95% confidence intervals (95% CIs) of CRD related hospitalizations. RESULTS: Our results showed that fine particulate matter (PM2.5), inhalable particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) were associated with CRD-related hospitalizations in people aged ≥ 65 years. We observed that each 10 µg/m3 increase (except for each 0.1 mg/m3 increase in CO) in the concentration of air pollutants, the percentage of CRD-related hospitalizations due to PM2.5, PM10, and SO2 exposure at lag 07, NO2 exposure at lag 03, and CO exposure at lag 0 increased by 2.13% (95% CI: 0.55%, 3.74%), 1.76% (95% CI: 0.70%, 2.83%), 8.24% (95% CI: 0.92%, 16.09%), 2.16% (95% CI: 0.26%, 4.05%), and 1.19% (95% CI: 0.26%, 2.12%), respectively. In addition, we found stronger effects of particulate matter in 75-84 years age group, on warmer days, and in asthmatics. CONCLUSION: In conclusion, air pollution may have adverse effects on CRD-related hospitalizations among people aged ≥ 65 years in Ningbo. Therefore, public health measures should be taken to improve air quality.