Percentage of population exposed to a fine particulate matter (PM2.5) concentration greater than 15 micrograms (μg) per cubic meter (m3).

The World Health Organization (WHO) provides air quality guidelines based on scientific evidence and expert advice. 15 μg/m3 is interim target-3. In addition to other health benefits, these levels reduce the mortality risk by approximately 6% [2-11%] relative to the IT-2 level (25 μg/m3).