Image Credit: grynold/Shutterstock.com Air quality matters. The World Health Organization estimates that there has been an 8% rise in air pollution in recent years, with poorer cities experiencing the most deterioration. Over 91% of people now breathe air polluted with noxious gases and particulates, mostly from fossil fuel combustion. Air pollution is the fourth leading risk factor for deaths worldwide. There were an estimated 10.2 million deaths related to airborne particulates in 2012, namely PM2.5. A total of 62% of these premature deaths were in China (3.9 million) and India (2.5 million) where pollution is high, with the rest located in parts of the eastern US, Europe, and Southeast Asia.