14 July 2019
A growing body of evidence is showing a clear association between short-term exposure to air pollution, and hospital admissions and deaths due to heart failure. Despite developing countries experiencing some of the most severe air pollution, analyses in those countries have been sparse. Researchers in Beijing have addressed this gap by analysing data from 26 large cities across China. They believe the association they detected may have significant public health implications for preventing congestive heart failure in China, and suggest their results are relevant to other countries.
The study, led by Yonghua Hu at the School of Public Health at Peking University, Beijing, looked for correlations between daily hospital admissions and changing air pollution levels in 2014 and 2015. The air pollution data covered the levels of several specific pollutants, including particulate matter, sulphur dioxide, nitrogen dioxide, carbon monoxide and ozone. This information was gathered daily from fixed-site air-monitoring stations in each city. These are an established part of the China National Air Pollution Monitoring System.
After statistical analyses, the results showed that short-term increases in the levels of all of the pollutants analysed, with the exception of ozone, were associated with increased hospital admissions for congestive heart failure. The link was most notable in patients with diabetes or high blood pressure. The association identified in the study did not, however, vary significantly with age, history of other diseases, or the time of year.
“To our knowledge, this is the first multi-city study in China, or in other developing countries, to examine the relation between air pollution and congestive heart failure mortality," the authors say.
A strength of this study is its capacity to detect increases in hospitalization linked to spikes in air pollution on a timescale of days, as opposed to the effects of more generalized chronic pollution levels. By revealing the significance of short-term pollution spikes, the study suggests that steps to avoid such transient increases could bring significant health benefits.
The authors note that the significant detrimental health effects of air pollution cause widespread public concern in China, and the study validates that concern.
Liu, H., Tian, Y., Song, J., Cao, Y., Xiang, X. et al. Effect of ambient air pollution on hospitalization for heart failure in 26 of China’s largest cities. The American Journal of Cardiology 121, 628-633 (2018). | article