New air quality and health database will cover 1600 citiesListen /
A new database of air pollution levels and trends is covering 1600 cities in 91 countries, according to the World Health Organization (WHO).
The 2014 Air Quality global database is being launched in Geneva on Wednesday.
Covering 500 more cities than in 2011, it highlights the ones where air pollution and the related health risks are highest.
The database primarily captures measurements from monitoring stations in urban and residential areas.
Recent figures from WHO report that seven million people died in 2012 as a result of air pollution exposure.
That's one in eight of total deaths.
WHO said this finding confirms that air pollution is now the world's largest single environmental health risk.
Stephanie Coutrix, United Nations.