ABSTRACT
The aim of this study was to assess whether a correlation exists between fine particles (PM2.5) levels and number of hospital admissions for hypertension in Kaohsiung, Taiwan. Hospital admission frequency and ambient air pollution data were obtained for Kaohsiung for 2009–2013. A time-stratified case-crossover method was used to estimate relative risk for hospital admissions, controlling for weather, day of the week, seasonality, and long-term time trends. Odds ratios and 95% confidence intervals were calculated for a 10 µg/m3 increment of PM2.5 for lags from days 0 to 6. Data showed no significant associations between PM2.5 levels and number of hypertension-related hospital admissions on warm days (>25°C). However, on cool days (<25°C), a significant positive association was found with frequency of hypertension admissions in the single-pollutant model (without adjusting for other pollutants) with a 10 µg/m3 rise in PM2.5 on day of admission (lag 0) associated with a 12% increase in number of admissions for hypertension. In the two-pollutant model, the association of PM2.5 with rate of hypertension hospitalizations remained significant after including SO2 or O3 on lag day 0. Data demonstrate that an association between short-term exposure to PM2.5 and elevated risk of hypertension-related hospital admissions may exist in Kaohsiung, Taiwan, a tropical city.
Acknowledgments
This study is based in part on data from the National Insurance Research Database provided by the Bureau of National Health Insurance, Department of Health and managed by National Health Research Institutes. The interpretation and conclusions contained herein do not represent those of Bureau of National Health Insurance, Department of Health or National Health Research Institutes. This study was supported by a grant from Wang Jhan-Yang Charitable Trust Fund (WJY 2016-HR-01) and National Health Research Institutes, Taiwan (EM-105-PP-08).