According to the World Health Organization, pollution poses a serious health risk around the world. From heavy air smog hanging over cities to poor air quality inside homes, people in densely populated areas are constantly exposed to dangerous air pollution. The statistics are scary. More than 99% of the global population is exposed to dangerous levels of air pollution. This exposure is not just unpleasant, but also increases the chances of developing a number of serious illnesses.
Curious to see the top 25 most polluted countries? Click through the gallery.