A team of researchers from China, the U.S. and Norway has found that urging rural residents to switch from burning wood and grasses to cleaner fuels for cooking has resulted in less fine particulate matter being spewed into the air. In their paper published in Proceedings of the National Academy of Sciences, the group describes their study of air quality for the period from 2005 to 2015 in China and its impact on the health of the people living there.