GENEVA: Over 80 percent of the world’s city dwellers breathe poor quality air, increasing their risk of lung cancer and other life-threatening diseases, a new World Health Organization (WHO) report warned Thursday. Urban residents in poor countries are by far the worst affected, WHO said, noting that nearly every city (98 percent) in low- and middle-income countries has air, which fails to meet the UN body’s standards. That number falls to 56 percent of cities in wealthier countries. The UN agency’s latest air pollution database reveals an overall deterioration of air in the planet’s cities, and highlights the growing risk of serious health conditions also including stroke and asthma. The report, which focused on outdoor rather than household air, compared data collected from 795 cities in 67 countries between 2008 and 2013.