Exercise still beneficial, but less so, in high PM2.5 air: Study

Taipei, Dec. 3 (CNA) There are still health benefits to exercising when exposed to excessive levels of fine particulate matter (PM2.5), but they can be reduced by up to half, according to a study led by a National Chung Hsing University (NCHU) professor.

The study found that 150 minutes of moderate-intensity exercise per week can lower all-cause mortality by about 30 percent when PM2.5 exposure is below 25 micrograms per cubic meter (μg/m³).

The benefit drops to 12-15 percent lower mortality when exposure reaches or exceeds that level, Ku Po-wen (古博文), a distinguished professor at NCHU's Graduate Institute of Sports and Health Management and the study's lead researcher, said at a press event Wednesday.

Similar results were found for cardiovascular and cancer mortality rates, he said.

The protective effects of exercise on mortality were not significant, however, for cancer mortality at 35-50 μg/m³.

Ku said that while all of Taiwan's municipalities now have annual average PM2.5 levels lower than 25 μg/m³, those averages do not reflect real-world exposure at all times and locations.

Actual concentrations fluctuate with seasonal changes, weather conditions, topography, and traffic flow, he said.

Ku suggested that people who want to exercise outdoors check the air quality in real time and decide to exercise at times and places that have good air quality.

The study, which was a collaboration with research institutions across Asia, Europe, and Australia, compiled data from over 1.5 million adults from multiple countries over 10 years, according to a news release by NCHU.

It was published in the BMC Medicine Journal on Nov. 28.