A common air pollutant killed far fewer people in China in 2015 than it did in 2005, thanks in part to rural residents cutting back on the use of fuels such as wood and straw for cooking.
In 2005, China’s central government began setting restrictions on emissions of fine particulate matter — a mixture of microscopic particles that can be inhaled deep into the lungs — by vehicles, power plants and factories. To assess the campaign’s impact, Shuxiao Wang at Tsinghua University in Beijing, Kirk Smith at the University of California, Berkeley, and their colleagues modelled the Chinese population’s exposure to fine particulate matter.
The researchers found that deaths related to this form of pollution fell by 29% between 2005 and 2015. Surprisingly, government restrictions accounted for only a fraction of this decrease. Eighty per cent of the drop was spurred by a reduction in people’s use of wood and other dirty fuels for cooking and heating, as rural people either migrated to cities or gained enough income to buy cleaner fuels.