Soaring heat and fine particulate matter in the air may double your risk of death from a heart attack, according to a new study.
The study, published in the American Heart Association’s journal Circulation on Monday, analyzed over 200,000 heart attack deaths from 2015 to 2020 in a Chinese province with four distinct seasons and varying temperatures and pollution levels.
The results? Days with extreme heat, extreme cold, or high levels of fine particulate matter air pollution were all “significantly associated” with the risk of death from a heart attack.
The greatest risk was observed on days with both extreme heat and high air pollution levels. Women and older adults were particularly at risk.
“Extreme temperature events are becoming more frequent, longer and more intense, and their adverse health effects have drawn growing concern,” said senior author Dr. Yuewei Liu, an associate professor of epidemiology in the School of Public Health at Sun Yat-sen University in Guangzhou, China, in a news release.
“Another environmental issue worldwide is the presence of fine particulate matter in the air, which may interact synergistically with extreme temperatures to adversely affect cardiovascular health.”
The study found that the risk of a fatal heart attack was 18% higher during two-day heat waves with heat indexes at or above the 90th percentile, ranging from 82.6 to 97.9 degrees Fahrenheit.
The risk was 74% higher during four-day heat waves with heat indexes at or above the 97.5th percentile, ranging from 94.8 to 109.4 degrees.
Additionally, during four-day heat waves with fine particulate pollution levels above 37.5 micrograms per cubic meter, the risk was twice as high.
For context, the World Health Organization recommends no more than 15 micrograms per cubic meter for more than three to four days per year.
Despite their small size of less than 2.5 microns, fine particulates — mostly from car exhaust, factory emissions, or wildfires — can be inhaled deep into the lungs, irritating the lungs and blood vessels around the heart, the news release explains.
“Our findings provide evidence that reducing exposure to both extreme temperatures and fine particulate pollution may be useful to prevent premature deaths from heart attack, especially for women and older adults,” Liu added.
