Waiting on a roadside this month for a highway from Beijing to Hebei Province to reopen after it was closed because of low visibility on a day of heavy smog. Photo: Damir Sagolj / Reuters

By Dan Levin
13 August 2015 BEIJING (The New York Times) – Outdoor air pollution contributes to the deaths of an estimated 1.6 million people in China every year, or about 4,400 people a day, according to a newly released scientific paper [pdf]. The paper maps the geographic sources of China’s toxic air and concludes that much of the smog that routinely shrouds Beijing comes from emissions in a distant industrial zone, a finding that may complicate the government’s efforts to clean up the capital city’s air in time for the 2022 Winter Olympics. The authors are members of Berkeley Earth, a research organization based in Berkeley, Calif., that uses statistical techniques to analyze environmental issues. The paper has been accepted for publication in the peer-reviewed scientific journal PLOS One, according to the organization [cf. Koch-funded study finds 2.5°F warming of land since 1750 is manmade – ‘Solar forcing does not appear to contribute’]. According to the data presented in the paper, about three-eighths of the Chinese population breathe air that would be rated “unhealthy” by United States standards. The most dangerous of the pollutants studied were fine airborne particles less than 2.5 microns in diameter, which can find their way deep into human lungs, be absorbed into the bloodstream and cause a host of health problems, including asthma, strokes, lung cancer and heart attacks. The organization is well known for a study that reviewed the concerns of people who reject established climate science and found that the rise in global average temperatures has been caused “almost entirely” by human activity. The researchers used similar statistical methods to assess Chinese air pollution. They analyzed four months’ worth of hourly readings taken at 1,500 ground stations in mainland China, Taiwan, and other places in the region, including South Korea. The group said it was publishing the raw data so other researchers could use it to perform their own studies. Berkeley Earth’s analysis is consistent with earlier indications that China has not been able to successfully tackle its air pollution problems. Greenpeace East Asia found in April that, of 360 cities in China, more than 90 percent failed to meet national air quality standards in the first three months of 2015. The Berkeley Earth paper’s findings present data saying that air pollution contributes to 17 percent of all deaths in the nation each year. [more]

Study Links Polluted Air in China to 1.6 Million Deaths a Year Time evolution of PM2.5 pollution in the vicinity of Beijing. (Top) Time series of PM2.5 concentration at Beijing extracted from the interpolated field. Red circles indicate times shown in bottom row. (Bottom) Maps of interpolated PM2.5 concentration during a period of high pollution. Bold circles show station locations with the observed value at each station indicated by the color within the circle. Graphic: Rohde and Muller, 2015 / PLOS One

ABSTRACT: China has recently made available hourly air pollution data from over 1500 sites, including airborne particulate matter (PM), SO2, NO2, and O3.  We apply Kriging interpolation to four months of data to derive pollution maps for eastern China.  Consistent with prior findings, the greatest pollution occurs in the east, but significant levels are widespread across northern and central China and are not limited to major cities or geologic basins.  Sources of pollution are widespread, but are particularly intense in a northeast corridor that extends from near Shanghai to north of Beijing.  During our analysis period, 92% of the population of China experienced >120 hours of unhealthy air (US EPA standard), and 38% experienced average concentrations that were unhealthy.  China’s population-weighted average exposure to PM2.5 was 52 µg/m3.  The observed air pollution is calculated to contribute to 1.6 million deaths/year in China [0.7–2.2 million deaths/year at 95% confidence], roughly 17% of all deaths in China. 

Air Pollution in China: Mapping of Concentrations and Sources