This is junk science because…
… this is an “ecologic” type study, in which the researchers have no idea how much air pollution anyone in the studied populations inhaled. They also have no information on the myriad factors that could explain the reported differences in mortality. In the end, they cannot conclude that air pollution was a factor in anyone’s death.
Moreover, heavy smoking is thought to reduce life expectancy by about 6+ or so years and heavy smokers inhale thousands of time more “air pollution” than non-smokers. Therefore, it is not credible to claim that air pollution reduces life expectancy by 5+ years.
Air pollution is shortening the lives of people in northern China by about 5.5 years compared to the south, a disastrous legacy of a policy that provided free coal for heating in the north, an international study shows.
Environmental problems are a source of rising social discontent in China; last month Beijing promised new measures to crack down on air pollution, partly by hastening a shift to renewable energy from fossil fuels.
The report, by experts in China, the United States and Israel, said a communist policy of giving out free coal everywhere north of the Huai River in central China between 1950 and 1980 meant more heart and lung disease among 500 million people living in the area.
“Life expectancies are about 5.5 years lower in the north owing to an increased incidence of cardio-respiratory mortality,” the researchers wrote in Tuesday’s edition of the Proceedings of the National Academy of Sciences (PNAS).