Associations between Air Pollution and Daily Emergency Room Visits for Cardio-Respiratory Diseases
Date Issued
2009
Date
2009
Author(s)
Lin, Yu-Lun
Abstract
Many studies indicate that urban air pollution may increase the risk of mortality and mobility for cardio-respiratory diseases, but most of these studies focus on particulate matter mass concentrations. Epidemiological studies examined the impact of particulate matter number concentrations and components on health effects were very few. The objective of this study is to examine the association between particle number concentrations and particulate components and emergency room visits for cardiovascular and respiratory diseases in Taipei metropolitan area. We linked the environmental data obtained from the Supersite in Sinjhuang and air monitoring stations in Taipei metropolitan area with emergency room visits for cardiovascular (ICD-9 codes: 390-459 and 785) and respiratory (ICD-9 codes: 460-519 and 786) diseases in National Taiwan University Hospital form 2004 January 1 to 2008 August 31. We first built base models for different diseases categories, including cardiovascular diseases and respiratory disease, without air pollution. The time-trend variables used in the base models included year, month and day-of-week. The meteorological variables included temperature, relative humidity and precipitation. Generalized additive models (GAM) were applied from lag 0 to 5 days and 2-day to 5-day moving average in our statistical analysis. Study results were expressed with relative risks (RRs) for an IQR (interquartile ranges) increase in each air pollutant. The particulate components analyzed in this study included nitrate, sulfate, black carbon (BC), organic carbon (OC) and element carbon (EC). Study results showed that particulate components were significantly associated with cardiovascular and respiratory diseases in single-pollutant models. We adjusted the effects of gaseous pollutants, carbon monoxide (CO) and ozone (O3), and PM10 or PM2.5 together to build multi-pollutant models. The associations between nitrate, sulfate, BC, OC and EC and respiratory diseases were still observed. The maximum RRs for each pollutant were 1.025, 1.025, 1.023, 1.031and 1.012, respectively. But for cardiovascular diseases, the associations were only found for sulfate, OC and EC with the maximum RRs were 1.020, 1.061 and 1.017. We further divided emergency room visits into three age groups, children (age 0-14 years), adults (age 15-64 years) and elderly (age above 65 years), to examine the effects of components. Nitrate, sulfate, BC, OC and EC were associated with emergency room visits for respiratory disease in adults group. The maximum RRs were 1.031, 1.043, 1.037, 1.050 and 1.020, respectively. For cardiovascular diseases in adults, the relations were only found in sulfate, OC and EC with the maximum RRs were 1.068, 1.060 and 1.036. In children, the associations between particles components and respiratory diseases were observed. The maximum RRs for nitrate, sulfate, BC, OC and EC were 1.036, 1.020, 1.030, 1.046 and 1.015. However, the impacts of particles components on cardiovascular diseases for elderly were only observed at lag 0 day for nitrate and OC. The maximum RRs were 1.017 and 1.050. Sulfate and OC were found increase the risk of respiratory diseases with the maximum RRs were 1.045 and 1.032. Those results indicate that particulate components have important influence on emergency room visits for cardiovascular and respiratory diseases, and the stronger effects were observed in adults group.
Subjects
particulate components
emergency room visits
cardiovascular diseases
respiratory diseases
Type
thesis
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