China’s Huai River policy provided free winter heating via the provision of coal for boilers in cities north of the Huai River. This increased total suspended particulates (TSPs) in Northern China by 55% compared to the South, reducing life expectancies by about 5½ years.
Nature quotes co-author Michael Greenstone,
“This study highlights that reducing the use of fossil fuels, especially coal, can have immediate benefits completely separate from climate. This is a good argument for reducing reliance on coal not only to appease the US and Europeans, but to improve the health and wellbeing of their citizens.”