Effects of Air Pollution on Hospital Emergency Room Visits for Respiratory Diseases: Urban-Suburban Differences in Eastern China

Abstract

A study on the relationships between ambient air pollutants (PM2.5, SO₂ and NO₂) and hospital emergency room visits (ERVs) for respiratory diseases from 2013 to 2014 was performed in both urban and suburban areas of Jinan, a heavily air-polluted city in Eastern China. This research was analyzed using generalized additive models (GAM) with Poisson regression, which controls for long-time trends, the "day of the week" effect and meteorological parameters. An increase of 10 μg/m³ in PM2.5, SO₂ and NO₂ corresponded to a 1.4% (95% confidence interval (CI): 0.7%, 2.1%), 1.2% (95% CI: 0.5%, 1.9%), and 2.5% (95%: 0.8%, 4.2%) growth in ERVs for the urban population, respectively, and a 1.5% (95%: 0.4%, 2.6%), 0.8% (95%: -0.7%, 2.3%), and 3.1% (95%: 0.5%, 5.7%) rise in ERVs for the suburban population, respectively. It was found that females were more susceptible than males to air pollution in the urban area when the analysis was stratified by gender, and the reverse result was seen in the suburban area. Our results suggest that the increase in ERVs for respiratory illnesses is linked to the levels of air pollutants in Jinan, and there may be some urban-suburban discrepancies in health outcomes from air pollutant exposure.

Keywords: air pollution; emergency room visits; respiratory diseases; urban-suburban discrepancies.

Figure A1

Smooth function curves of relative humidity and temperature: (a) relative humidity; (b) temperature.

Figure 1

Time series distributions of SO₂, NO₂ and PM_2.5 in Jinan during 2013 to 2014. The horizontal lines in (a); (b) and (c) represent the standard daily average limits of SO₂ (150 μg/m³), NO₂ (80 μg/m³) and PM_2.5 (75 μg/m³) in Chinese National Ambient Air Quality Standards (CNAAQS), respectively.

Figure 2

Relative risks (RRs with 95% CI) of hospital emergency room visits for respiratory complaints in association with per 10μg/m³ increase in PM_2.5, SO₂ and NO₂ for the urban population of Jinan at different lags (lag0, lag1, lag2, lag3, lag4).

Figure 3

Relative risks (RRs with 95% CI) of hospital emergency room visits for respiratory complaints in association with per 10 μg/m³ increase in PM_2.5, SO₂ and NO₂ for the suburban population of Jinan at different lags (lag0, lag1, lag2, lag3, lag4).

Figure 4

Adjusted estimated relative risks (RRs with 95% CI) of emergency room visits due to respiratory complaints with per 10 μg/m³ increase in PM_2.5, SO₂ and NO₂ in multi-pollutant models for the urban population in Jinan.

Figure 5

Adjusted estimated relative risk (RRs with 95% CI) of emergency room visits due to respiratory complaints with per 10 μg/m³ increase in PM_2.5, SO₂ and NO₂ in muti-pollutant models for the suburban population in Jinan.