Ammonium Nitrate Chemistry

Mixed Results in Air Pollution Scorecard

Air pollution is responsible for 7 million deaths annually, with 9 in 10 people worldwide breathing polluted air, according to new estimates from the the World Health Organization (WHO).

The WHO identify air pollution as a major global health concern, contributing to heart disease, stroke, cancer, and respiratory diseases.  To help address this they set guidelines for safe exposure limits to key pollutants including particulate matter (PM), ozone, and nitrogen dioxide, and also maintain a global air quality database which tracks PM2.5 and PM10 levels in 4000 locations worldwide.

Peering into the WHO data there are good and bad stories to tell.  Air pollution deaths are concentrated in South East Asia and the Western Pacific, where poor air quality coincides with high population densities.  Interestingly the latest data shows that the worst affected cities in these regions are predominantly in India, whereas air quality in China appears to be improving in the wake of citizen action and increased political attention.  Africa is an emerging pollution hot-spot, but it also has the worst coverage in the WHO database with only 8 of 47 countries included.  In Europe, Poland is the biggest air pollution offender, with many of the continent's most affected cities.  Poland have, however, recently announced a major program to battle their poor winter air quality through improved heating and insulation practices.  Finally, the Americas can lay claim to some of the world's cleanest air, but pollution is still a concern in many major cities.  Only this week was it reported that reductions in air pollutants in the USA have unexpectedly slowed over the last decade.

Measuring and reporting on atmospheric pollutants is an important step in the battle against air pollution. The WHO database is a key repository for this data and I hope to see it grow in coming years.