Pollution is highly unequal around the world, and so are policy ambitions

Whether pollution is increasing or decreasing, it’s clear that some regions of the world are much more polluted than other regions. People living in the most polluted places (most polluted quintile) breathe air that is six times more polluted than the air breathed by those living in the least polluted places (least polluted quintile). That means that pollution in the most polluted places is cutting 2.7 more years off the lives of those living in them compared to those in the cleanest places.

While geographic terrain and meteorological factors can have an influence on pollution, varying policy ambitions in the form of clean air standards—and the ability of countries to enforce them—are a primary determinant of pollution levels. Yet, national air quality standards vary significantly around the world, with some countries setting strict limits as low as the WHO guideline, others setting looser limits up to 50 µg/m³, and some having no standards at all.

Together, 78.2 percent of countries and territories worldwide have either not met or do not have a national standard.