To run or not to run on a smoggy day?

Harmful PM 2.5 particles in Beijing hit more than 320 micrograms per cubic meter on Sunday, at least 13 times the safety limit set by the World Health Organization.

Wang Guangfa, director of the respiratory medicine department of Peking University First Hospital, told China Daily that people should avoid going outside in such heavy smog, let along running a marathon.

The fine PM 2.5 particles could enter into the lower respiratory tract and settle down there, which, as previous scientific studies discovered, could lead to complicated conditions such as inflammatory reaction in the lungs or the whole body, he noted.

Longtime and frequent exposure to toxic air pollution, especially fine particles, could cause or worsen conditions such as chronic obstructive pulmonary disease and asthma, he added.

"Acute onset of such problems might lead to death," he warned.

For very healthy people, the negative health impact might not be instant, but it exists, he said.

Dwight W. Clark, medical director of the US-Sino HeartCare Center, said PM 2.5 is the type of air pollution most likely to cause cardiovascular diseases as well.

This small particulate matter appears to directly increase the risk of cardiac arrhythmias, heart attack and stroke, he said.

Air pollution was responsible for 7 million deaths in 2012, according to the WHO. One out of every eight premature deaths in 2012 was attributable to air pollution.

shanjuan@chinadaily.com.cn

(China Daily USA 10/20/2014 page5)