More than 80% of people living in urban areas are exposed to unsafe air quality, according to a report released by the World Health Organization Thursday.
"Urban air pollution continues to rise at an alarming rate, wreaking havoc on human health," WHO Director of Public Health and Environmental Policy Dr. Maria Neira said in the report. "At the same time, awareness is rising and more cities are monitoring their air quality."
In the past two years, the WHO's database of cities monitoring air pollution has nearly doubled - now covering 3000 cities in 103 countries.
The WHO warned of the serious affects poor air quality could have on the health of urban residents, linking it to risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases including asthma.
The report also showed that low- and middle-income countries generally have poorer air quality. 98% of cities with 100,000 or more inhabitants in low- and middle-income countries do not meet WHO air quality guidelines, while 56% in high-income countries fail to meet the standard.