Acute exposure to fine particulate matter and cardiovascular hospital emergency room visits in Beijing, China.

Fine particulate matter (PM) air pollution outbreaks have recently occurred frequently in China. However, evidence of the associations between short-term exposure to PM and cardiovascular morbidity is still limited in China. This study aimed to evaluate the associations between PM and hospital emergency room visits (ERVs) for cardiovascular diseases in urban areas in Beijing. Daily counts of cardiovascular ERVs were collected from ten large general hospitals from Jan 1 to Dec 31, 2013. Air pollution data were obtained from the Beijing Environmental Protection Bureau including 17 monitoring stations. A generalized additive Poisson model was used to examine the associations between PM and cardiovascular ERVs after controlling for seasonality, day of the week, public holidays, influenza outbreaks, and weather conditions. In total, there were 56,221 cardiovascular ERVs during the study period. The daily mean PM concentration was 102.1 μg/m, ranging from 6.7 μg/m to 508.5 μg/m. Per 10 μg/m increase in PM was associated with a 0.14% (95% confidence interval [CI]: 0.01%-0.27%) increase in cardiovascular ERVs at lag. Cumulative delayed estimates were greatest at lag (0.30%, 95% CI: 0.09%-0.52%). The estimates of percentage change in daily ERVs per 10 μg/m increase in PM were 0.56% (95%CI: 0.16%-0.95%) for ischemic heart disease (IHD) at lag, 0.81% (95%CI: 0.05%-1.57%) for heart rhythm disturbances (HRD) at lag and 1.21% (95%CI: 0.27%-2.15%) for heart failure (HF) at lag, respectively. The effects of PM on IHD ERVs during high temperature days (>11.01 °C) were significantly higher than that on low temperature days (≤11.01 °C) at lag, lag, lag and lag (P < 0.05). The study suggests that PM has acute impacts on cardiovascular ERVs in Beijing, especially on IHD, HRD and HF. The effects of PM on IHD ERVs vary by temperature.