Association of particulate matter with cardiovascular diseases in Bangkok

Abstract

The association between air pollution and cardiovascular diseases is well known, but previous studies only assessed in America and Europe. Few studies have been conducted in less-developed countries in regions with a tropical climate. This study aimed to evaluate the association between short-term exposures to fine particulate matter (PM10) in relation to hospital visits for CVD (I00–I99) in inner Bangkok. Data from hospital records were obtained from three major government hospitals. All hospital visits were stratified by age group and category of CVD. Daily PM10 levels and the weather reported by the Pollution Control Department (PCD) and the Meteorology Department from April 2002 to December 2006 (1,736 days) were used in time series analysis with GAM procedure in the Statistical Analysis Software (SAS). Exposures on the previous day (lag1) to PM10 had positive association with hospital visits for CVD in the elderly (≥ 65 years). The increase in CVD hospital visits in this age group was 0.10% (95% CI: 0.03, 0.19) with increase in PM10 by 10 µg m-3. This research, also study the incidence of CVD by standards cardio-respiratory questionnaires (ATS-DLD and CDQ). 330 elderly existing CVD patients visit Ramathibodi hospital from June to October 2007 was investigated. After adjusting all confounding by questionnaires and interviewed, there were 8 qualified subjects conducted HRV measurement for 24 hours. The hourly PM10 concentration and meteorology data were assessed from nearby PCD monitoring stations. The multiple logistic regression analysis was carried out to evaluate the relationships between PM10 and HRV. The percentage change of heart rate (HR) increasing was 0.37 % (95% CI; -0.01, 0.73) while SDNN and r-MSSD parameter of HRV were decreasing by -1.7% (95% CI; -2.6, -1.2) and -2.8 % (95% CI; -4.6, -1.0) respectively. The magnitude association change per 10 µg m-3 increase in PM10. Elevated levels of ambient PM10 may adversely affect HRV functions in elderly subjects with existing CVD patients in inner Bangkok.