Air pollution threatens global health and reduces life expectancy in major cities. Photo credit: NurPhoto/GettySource: Getty ImagesWHO warning on air pollutionAccording to the World Health Organization (WHO), 99% of the global population was exposed to air pollution levels that exceeded health-based guidelines. Air pollution was described as the world’s single largest environmental risk, linked to nearly 7 million premature deaths each year. The report noted that in New Delhi, air pollution had reached a crisis point. UK deaths linked to air pollutionThe Royal College of Physicians recently published findings that 30,000 deaths a year in the UK were linked to air pollution.