Coarse Particulate Air Pollution Associated with Increased Risk of Hospital Admissions for Respiratory Diseases in a Tropical City, Kaohsiung, Taiwan.

Chun-Yuh Yang*,Meng-Hsuan Cheng,Shang-Shyue Tsai

doi:10.1289/isee.2016.3167

Abstract

This study was undertaken to determine whether there was an association between coarse particles (PM₂.₅-₁₀) levels and frequency of hospital admissions for respiratory diseases (RD) in Kaohsiung, Taiwan. Hospital admissions for RD including chronic obstructive pulmonary disease (COPD), asthma, and pneumonia, and ambient air pollution data levels for Kaohsiung were obtained for the period from 2006 to 2010. The relative risk of hospital admissions for RD was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the single pollutant model (without adjustment for other pollutants), increased rate of admissions for RD were significantly associated with higher coarse PM levels only on cool days (<25 °C), with a 10 µg/m³ elevation in PM₂.₅-₁₀ concentrations associated with a 3% (95% CI = 1%-5%) rise in COPD admissions, 4% (95% CI = 1%-7%) increase in asthma admissions, and 3% (95% CI = 2%-4%) rise in pneumonia admissions. No significant associations were found between coarse particle levels and the number of hospital admissions for RD on warm days. In the two-pollutant models, PM₂.₅-₁₀ levels remained significantly correlated with higher rate of RD admissions even controlling for sulfur dioxide, nitrogen dioxide, carbon monoxide, or ozone on cool days. This study provides evidence that higher levels of PM₂.₅-₁₀ enhance the risk of hospital admissions for RD on cool days.

Highlights

Over the past decade, many epidemiologic studies demonstrated positive associations between ambient levels of particulate matter (PM) (generally measured as PM with an aerodynamic diameter < 10μm (PM10)) and daily mortality and hospital admissions or emergency room (ER) visits for cardiovascular and respiratory morbidity [1,2,3,4,5]
This study was undertaken to examine the short-term associations of daily concentrations of PM2.5–10 with frequency of hospital admissions for respiratory diseases (RD) including chronic obstructive pulmonary disease (COPD), asthma, and pneumonia among individuals residing in Kaohsiung city, a large industrial city in southwest Taiwan, over a 5 year period from 2006 to 2010, using a case-crossover design
During the 5 years of the study, there were a total of 81,836 hospital admissions for RD (14,136 for COPD, 5222 for asthma, and 62,478 for pneumonia) for the 63 hospitals in Kaohsiung City

Summary

Introduction

Many epidemiologic studies demonstrated positive associations between ambient levels of particulate matter (PM) (generally measured as PM with an aerodynamic diameter < 10μm (PM10)) and daily mortality and hospital admissions or emergency room (ER) visits for cardiovascular and respiratory morbidity [1,2,3,4,5]. Fewer studies have examined the potential adverse health effects attributed to the coarse fraction, that is, particles ranging in size from 2.5μm to 10μm in aerodiameter (PM2.5–10) [14]. The adverse health effects associated with ambient exposure to PM2.5–10 may differ from those of PM2.5 considering differences in the sites of deposition in the respiratory tract and sources and chemical composition for these two different-sized fractions [19]. This study was undertaken to examine the short-term associations of daily concentrations of PM2.5–10 with frequency of hospital admissions for RD including chronic obstructive pulmonary disease (COPD), asthma, and pneumonia among individuals residing in Kaohsiung city, a large industrial city in southwest Taiwan, over a 5 year period from 2006 to 2010, using a case-crossover design

Kaohsiung City

Hospital Admission Data

Pollutant and Meteorological Data

Statistics

Results and Discussion

Conclusions