New research shows high air pollution levels may make people more susceptible to suffering a stroke.
In previous research, air pollution levels have been connected to daily death rates for respiratory
problems and heart disease. But research on air pollution and stroke has been conflicting. Investigators from Kaohsiung Medical University in Taiwan conducted a study to compare air pollution levels and stroke hospital admissions.
Researchers collected data on 23,179 hospital stroke admissions from 1997 to 2000 in Kaohsiung, Taiwan. It is the second largest city on the island and is a heavy industrial area. Investigators compared air pollution levels on the dates of hospital admissions with air pollution levels one week before and one week after admissions.
The study shows two common pollutants were associated with an increase in the number of stroke admissions. "Particulate matter (PM10) and nitrogen dioxide (NO2) seem to be the most important pollutants and the effects appear to be stronger on warm days," says Chun-Yuh Yang, Ph.D., M.P.H., professor, director and dean at the Institute of Public Health, College of Health Sciences at Kaohsiung Medical University. Researchers found an increase of these air pollutants increased the risk of two types of stroke including an intracerebral hemorrhage stroke and an ischemic stroke. An intracerebral hemorrhage is when a defective brain vessel bursts and an ischemic stroke happens when a blood clot blocks blood flow to the brain.
Study authors conclude this research provides new evidence that higher levels of certain pollutants increase the risk of hospital admissions for a stroke.