China’s reliance on coal reduces life
expectancy by 5.5 years, study concluded
Air pollution causes people in northern China to live an average of 5.5 years shorter than their southern counterparts, according to a study which claims to show in unprecedented detail the link between air pollution and life expectancy. They also found the variation to be attributable to cardiorespiratory illness, and not to other causes of death. The study concluded that long-term exposure to air containing 100 micrograms of TSP per cubic meter “is associated with a reduction in life expectancy at birth of about 3.0 years.” What the researchers called “ambient particulate matter pollution” was the fourth-leading risk factor for deaths in China in 2010, behind dietary risks, high blood pressure and smoking. Air pollution ranked seventh on the worldwide list of risk factors, contributing to 3.2 million deaths in 2010. The smaller the particulate matter such as below 2.5 micrometers in diameter or smaller, penetrate the body’s tissues most deeply.
High levels of air pollution in northern China – much of it caused by an over-reliance on burning coal for heat – will cause 500 million people to lose an aggregate 2.5 billion years from their lives, the authors predict in the study, published in the journal the Proceedings of the National Academy of Sciences.
The geographic disparity can be traced back to China’s Huai River policy which, since it was implemented between 1950 and 1980, has granted free wintertime heating to people living north of the Huai river, a widely-acknowledged dividing line between northern and southern China. Much of that heating comes from the combustion of coal, significantly impacting the region’s air quality.
“Using data covering 20 years, an unusually long timespan – from 1981 through 2000 – the researchers found that air pollution … was about 55% higher north of the river than south of it,” Michael Greenstone of MIT Energy Initiative said in a statement.
“Linking the Chinese pollution data to mortality statistics from 1991 to 2000, the researchers found a sharp difference in mortality rates on either side of the border formed by the Huai River. They also found the variation to be attributable to cardiorespiratory illness, and not to other causes of death.”
The researchers, based in Israel, Beijing, and the Massachusetts Institute of Technology, gauged the region’s air quality according to the established metric of “total suspended particulates” (TSP)” representing the concentration of certain airborne particles per cubic meter of air.
The study concluded that long-term exposure to air containing 100 micrograms of TSP per cubic meter “is associated with a reduction in life expectancy at birth of about 3.0 years.”
Yet according to Michael Greenstone, an economics professor at MIT and one of the study’s authors, this study is the first to precisely quantify their relationship. “Demonstrating that people die a bit earlier [because of pollution] is interesting and helps establish that pollution is bad,” he said.
Past studies have established a link between air pollution and reduced life expectancy. One recent large-scale study concluded that air pollution contributed to 1.2 million premature deaths in China in 2010 nearly 40 percent of the global total, according to a new summary of data from a scientific study on leading causes of death worldwide.
Figured another way, the researchers said, China’s toll from pollution was the loss of 25 million healthy years of life from the population.
The data on which the analysis is based was first presented in the ambitious 2010 Global Burden of Disease Study, which was published in December in The Lancet, a British medical journal. The authors decided to break out numbers for specific countries and present the findings at international conferences.
What the researchers called “ambient particulate matter pollution” was the fourth-leading risk factor for deaths in China in 2010, behind dietary risks, high blood pressure and smoking. Air pollution ranked seventh on the worldwide list of risk factors, contributing to 3.2 million deaths in 2010.
By comparison with China, India, which also has densely populated cities grappling with similar levels of pollution, had 620,000 premature deaths in 2010 because of outdoor air pollution, the study found. That was deemed to be the sixth most common killer in South Asia.
The study was led by an institute at the University of Washington and several partner universities and institutions, including the World Health Organization.
Chinese officials cut out sections of a 2007 report called “Cost of Pollution in China” that discussed premature deaths. The report’s authors had concluded that 350,000 to 400,000 people die prematurely in China each year because of outdoor air pollution. The study was done by the World Bank in cooperation with the Chinese State Environmental Protection Administration, the precursor to the Ministry of Environmental Protection.
There have been other estimates of premature deaths because of air pollution. In 2011, the World Health Organization estimated that there were 1.3 million premature deaths in cities worldwide because of outdoor air pollution.
The Organization for Economic Cooperation and Development, based in Paris, warned that “urban air pollution is set to become the top environmental cause of mortality worldwide by 2050, ahead of dirty water and lack of sanitation.” It estimated that up to 3.6 million people could end up dying prematurely from air pollution each year, mostly in China and India.
Air that Kills
In a study published in the journal Environmental Research Letters, scientists used a number of mathematical models to estimates the effects of fine particulate matter – tiny particles , or soot, that penetrate deep into the lungs – and ozone, the main component of smog. “Our estimates make outdoor air pollution among the most important environment risk factors for health,” read a statement from lead study co-author Jason West, an assistant professor of environmental science at the University of North Carolina. “Many of these deaths are estimated to occur in East Asia and South Asia, where population is high and air pollution is severe,”
West and his colleagues concluded that about 470,000 people die each year from pollution by human industrial activities. The authors also concluded that an additional 2.1 million deaths were caused by fine particulate matter resulting from human activity. Such particulate measure smaller than 2.5 microns in width and are called, PM2.5. These particle have been linked to lung cancer and a variety of respiratory disease.