New research from the Sun Yat-sen University School of Public Health in Guangzhou, China, amplifies how air pollution could affect the trajectory of health from strokeTrusted Source to subsequent death.
The study, recently published in Neurology, focused on the health impacts of PM 2.5 granules. This fine particulate matter (PM) is harmful to human health and has a diameter of fewer than 2.5 microns, about 30 times smaller than a single human hair.
Researchers also looked at nitrogen dioxide (NO₂) and nitrogen oxides (NO𝑥) levels in polluted air and measured air pollutant levels by their weight in micrograms — 1-millionth of a gram — per 1 cubic meter of air, expressed as μg/m3.
The study shows that for every PM 2.5 increase of 5 μg/m3, the risk of a first stroke rose by 24%, and the risk of a first fatal stroke increased by 30%.
Each increase of 5 μg/m3 of NO₂ and NO𝑥 was associated with a small risk of a first stroke — 0.2% and 0.1%, respectively.
The pollutants also caused a slight increase in the risk of cardiovascular mortality for people who have already had a stroke. This was especially true of NO₂, which increased mortality risk by 0.04%, although this effect tapered off with time.
Dr. Franco Folino, Ph.D., research cardiologist in the department of Cardiac, Thoracic and Vascular Sciences at the University of Padova in Italy, not involved in the study, told Medical News Today.
“Despite the many studies that have shown the harmful effects of pollution on health, there still seems to be little awareness on the need to take adequate measures to reduce exposure to pollutants, particularly in populations at greater risk.”
The observational study is based on an analysis of the health records of 318,752 people in the UKBiobank and several years of UKBiobank air pollution data.