Only seven nations met the World Health Organization’s air‑quality standards last year, underscoring the growing challenge of smog worldwide.
Chad and Bangladesh topped the list of most polluted countries, with average fine‑particle concentrations more than fifteen times higher than the WHO guideline of 5 micrograms per cubic meter. In Chad, PM2.5 levels averaged 91.8 micrograms per cubic meter, a figure that rose slightly from the previous year.
Countries that achieved compliance include Australia, New Zealand, the Bahamas, Barbados, Grenada, Estonia, and Iceland.
Data gaps are pronounced, especially across Asia and Africa. Many developing nations have depended on monitoring stations installed by foreign embassies, and the recent cessation of that program leaves a significant portion of the world without reliable real‑time air‑quality data.
Chad was omitted from a recent global list because of data concerns, yet it remained the most polluted country in the previous year, its smog exacerbated by Sahara dust and uncontrolled crop burning.
Globally, only 17% of cities achieved the WHO’s recommended air‑quality level. India, which ranked fifth in overall smog, saw a 7% reduction in average PM2.5 to 50.6 micrograms per cubic meter but still hosts 12 of the 20 most polluted cities, including Byrnihat, which recorded 128 micrograms per cubic meter.
Climate change intensifies the problem by raising temperatures, which in turn fuels more frequent and longer forest fires across Southeast Asia and South America, adding to particulate pollution.
The elimination of the monitoring program will deprive at least 34 countries of dependable air‑quality data, undermining efforts to track and mitigate pollution.
Where the program operated, it improved local air quality, extended life expectancy, and reduced exposure for diplomatic staff, proving its value to both residents and foreign missions.
The loss of this infrastructure signals a more difficult battle against smog, as reliable data are essential for crafting effective environmental policies worldwide.
