China could save 3 million premature deaths every year by reducing air pollution to the level recommended by the World Health Organization (WHO), according to a study published Wednesday in The British Medical Journal.
The study was conducted by Chinese researchers who studied the effects of air pollution on deaths in 38 major Chinese cities – bringing together some 200 million people in total – between January 2010 and June 2013. During this period, the daily concentration of PM10 particulate matter (emitted mainly by road traffic, heating and agriculture) averaged 93.9 micrograms per cubic meter of air in the 38 cities, with a maximum of 135 μg / m3 in Urumqi, a city in northwestern China, with a minimum of 67 μg / m3 in Qinhuangdao, 300 km east of Beijing.
WHO recommends reducing this rate to an annual average of 20μg / m3, while according to figures published last year, more than 80% of people living in urban areas worldwide are exposed to Pollution levels exceeding this limit. M10 particles (with a diameter of less than 10 microns) are particularly dangerous because they can lodge in the airways.
Investigating the 350,000 deaths in the 38 cities between 2010 and 2013, researchers led by Zhou Maigeng of the Beijing Disease Control Center found that an increase in PM10 concentration of 10μg / m3 was associated with an increase in the daily number of deaths by 0.46%.
Exposure to PM10 was found to be more harmful overall among women and adults over 60 years of age, according to the study.
It also had a greater impact on cardiovascular disease with an increase in deaths of 0.63% for every 10 μg / m3 increase in PM10, while for other diseases, the increase was only 0.27%. The researchers agreed on the figure of three million premature deaths avoided each year in China by making a “summary calculation”, based in particular on a Chinese population of 1.33 billion.
They also added that this figure is likely to be underestimated because the effect of air pollution may be greater in rural areas (which have not been studied).