A recent study investigated the association between long-term exposure to air pollution and stroke.
Ambient air pollution, described as air pollution in the outdoor environment, is a major public health concern worldwide. According to the World Health Organization (WHO), ambient air pollution contributed to around 4.2 million deaths in a given year of which about 24 percent of those deaths were due to stroke. There is evidence that suggests fine particulate matter (pollution measuring less than 2.5 micrometers in diameter) is linked to various health risks.
Previous studies reported that short-term exposure to air pollution was associated with an increased risk of hospital admissions. Several studies suggested a link between long-term exposure to air pollution and stroke. However, most of those studies were conducted in North America and Europe in which the levels of pollution were lower than those of developing countries.
A recent study, published in BMJ, investigated the association between long-term exposure to ambient air pollution and stroke. The study recruited over 117,000 participants from China, who had not experience a stroke prior to the start of the study. Using spatiotemporal statistical models based on satellite remote sensing data, researchers obtained monthly estimates of air pollution levels around the participants’ residences between the years 2000 and 2015.
The results of the study report an almost linear exposure and response relationship between long-term exposure to air pollution and stroke. The findings suggest that long term exposure to high concentrations of ambient air pollution is associated with an increased risk of stroke. The broad distribution of participants across China, covering over a wide range of geographical pollution levels, provided a valuable opportunity for the researchers to assess the exposure and response relationship. According to the researchers, the findings are important for developing air quality and stroke prevention policies in low- and middle-income countries.
Written by Ranjani Sabarinathan, MSc
Huang K, Liang F, Yang X, et al. (2019). Long term exposure to ambient fine particulate matter and incidence of stroke: prospective cohort study from the China-PAR project. BMJ. doi: 10.1136/bmj.l6720
Ambient air pollution: Health impacts. Retrieved from https://www.who.int/airpollution/ambient/health-impacts/en/
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