Long-Term Exposure to Ambient Air Pollution and Mortality Due to Cardiovascular Disease and Cerebrovascular Disease in Shenyang, China

Pengfei Zhang,Hui Huang,Fei Yu,Naijun Tang,Nannan Ma,Baijun Sun,Huimin Guo,Jie Chen,Xi Chen,Liwen Zhang,Yungling Leo Lee,Guanghui Dong,Massimo Federici

doi:10.1371/journal.pone.0020827

Abstract

BackgroundThe relationship between ambient air pollution exposure and mortality of cardiovascular and cerebrovascular diseases in human is controversial, and there is little information about how exposures to ambient air pollution contribution to the mortality of cardiovascular and cerebrovascular diseases among Chinese. The aim of the present study was to examine whether exposure to ambient-air pollution increases the risk for cardiovascular and cerebrovascular disease.Methodology/Principal FindingsWe conducted a retrospective cohort study among humans to examine the association between compound-air pollutants [particulate matter <10 µm in aerodynamic diameter (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2)] and mortality in Shenyang, China, using 12 years of data (1998–2009). Also, stratified analysis by sex, age, education, and income was conducted for cardiovascular and cerebrovascular mortality. The results showed that an increase of 10 µg/m3 in a year average concentration of PM10 corresponds to 55% increase in the risk of a death cardiovascular disease (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.51 to 1.60) and 49% increase in cerebrovascular disease (HR, 1.49; 95% CI, 1.45 to 1.53), respectively. The corresponding figures of adjusted HR (95%CI) for a 10 µg/m3 increase in NO2 was 2.46 (2.31 to 2.63) for cardiovascular mortality and 2.44 (2.27 to 2.62) for cerebrovascular mortality, respectively. The effects of air pollution were more evident in female that in male, and nonsmokers and residents with BMI<18.5 were more vulnerable to outdoor air pollution.Conclusion/SignificanceLong-term exposure to ambient air pollution is associated with the death of cardiovascular and cerebrovascular diseases among Chinese populations.

Highlights

Ambient air pollution significantly increases both morbidity and mortality in the general population [1,2,3,4,5,6]
The development of respiratory diseases resulting from direct contact of the respiratory system with air pollutants has been widely acknowledged as a major component of the adverse health effects of air pollution [7]
It has been reported that lignites from a local Shenyang coal field had the highest concentrations of nickel (75 mg/g) and chromium (79 mg/g) in the world, and some carcinogenic substances in coal were released into the air during the combustion of lignites in Shenyang [18]

Summary

Introduction

Ambient air pollution significantly increases both morbidity and mortality in the general population [1,2,3,4,5,6]. During the past two decades, air pollution-induced cardiovascular and cerebrovascular toxicities have become the focus of intensive studies among cardiologists and specialists in environmental medicine [8,9,10,11] Despite these studies, the relationship between ambient air pollution and cardiovascular and cerebrovascular diseases is still controversial. It has been reported that various factors, such as sex, age, education, and occupational exposure, can modify the relationship between air pollution and mortality [19], and the effects of air pollution exposure on health are greater in people with lower socioeconomic status (SES) [20] Most of these studies were conducted in developed countries, and only a small number of studies have been conducted in Asia. The aim of the present study was to examine whether exposure to ambient-air pollution increases the risk for cardiovascular and cerebrovascular disease

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Results

Conclusion