THURSDAY, Jan. 30, 2020 (HealthDay News) -- All it takes is short-term exposure to fine-particle air pollution from cars and bushfires to increase the risk of cardiac arrest, a new study warns.

The findings underscore the need for tighter worldwide limits on so-called PM2.5 air pollution and development of cleaner energy sources, according to the authors.

"As no boundary exists in air quality among countries, a global approach to tackle this crucial health issue is necessary for our planet," they wrote Jan. 27 in The Lancet Planetary Health journal.

The analysis of data from Japan reported 1% to 4% higher odds of out-of-hospital cardiac arrest to every increase of 10 micrograms per cubic meter in PM2.5 (particulate matter 2.5 micrometers of less). These particles are so small they can only be seen with a microscope, and their light weight keeps them suspended in the air longer.

Elderly people are at greatest risk.

"Out-of-hospital cardiac arrest is a major medical emergency -- with less than one in 10 people worldwide surviving these events -- and there has been increasing evidence of an association with the more acute air pollution, or fine particulate matter such as PM2.5," said study senior author Dr. Kazuaki Negishi. He's a cardiologist and head of medicine at the University of Sydney's Nepean Clinical School in Australia.

His team analyzed almost a quarter-million cases of out-of-hospital cardiac arrests. While the study couldn't prove a cause-and-effect link, it found a clear association between the heart condition and pollution levels.

"Our study supports recent evidence that there is no safe level of air pollution," Negishi said in a university news release.

"Given the fact that there is a tendency towards worsening air pollution -- from increasing numbers of cars as well as disasters such as bushfires -- the impacts on cardiovascular events, in addition to respiratory diseases and lung cancer -- must be taken into account in health care responses," he added.

The study also found a link between cardiac arrest and short-term exposure to carbon monoxide, photochemical oxidants and sulfur dioxide.

Researchers said there is an "urgent" need to improve air quality worldwide.

More information

The American Heart Association has more on air pollution and the heart.