In a recent research article published by American science journal Proceedings of the National Academies of Sciences (PNAS), researchers have discovered that the life expectancy of residents in Northern China has decreased by an average of 5.5 years, and air pollution is to blame. The Washington Post sums up the findings:
“[The new study] uses a quasi-natural experiment to quantify the effects of air pollution from China’s coal use in recent decades.
The study concluded that nearly 500 million people living north of the Huai River will lose an estimated 2.5 billion life years because of pollution from widespread coal burning, compared with those south of the river. The study is based on analyses of health and air-quality data from 1981 to 2000.”
One of the authors, Michael Greenstone, told The New York Times that all age groups in Northern China have higher mortality rates than their counterparts in Southern China. The main factor, as the study and NYT suggest, is coal burning:
“Its conclusions are based on analyses of population groups living in areas north and south of the Huai River. The Chinese government has for years maintained a policy of free coal for boilers to generate winter heating north of the river, which runs parallel to and between the Yellow and Yangtze Rivers. That policy and the ubiquity of northern coal-fired factories have contributed to the vast gap between the coal pollutants emitted in north and south.”
While the logic is sound, heating in the winter is not free in Northern China. In Beijing, heating costs 25 to 30 RMB per square meter, which amounts to around 2500 to 3000 RMB per household for the winter. Places in the north without central heating burn coal, with a typical family consuming 2 to 3 tons of coal during the winter months.
The 5.5 years of decreased life expectancy comes from the rise in deaths related to cardio-respiratory diseases, the NYT continues, and that outdoor air pollution has contributed to 1.2 million premature deaths in 2010 in China.
Northern China has traditionally been reliant on coal mining and burning, iron and steal production, building materials, and other heavy industries. Earlier this year, when Chinese cities were tested according to the new Air Pollution Index (API) environmental principles, almost all of the top 10 most polluted cities were in the north. On the other hand, Southern China traditionally has a focus on agriculture and commerce, with a milder climate and thus has more advantages environment-wise than the somewhat bleak and barren Northern regions.
We do not yet know how the study eliminates other variables to come to the conclusion that the life span drop by 5.5 years in the North is directly because of coal burning. Southern China has complained about not having central heating due to its freezing yet humid winters, perhaps this new finding will appease their grievances.
Image courtesy of Xinhua News.