WHO Names Onitsha World's Most Polluted City

The World Health Organisation (WHO) has tagged Onitsha, in Nigeria,the world’s most polluted city.
According to the report published by the World Economic Forum (WEF),

Onitsha produced pollution “levels of nearly 600 micrograms per cubic metre of PM10s – around 30 times the WHO recommended level of 20 micrograms per cubic metre,” to get the unenviable rating.
Onitsha, along with three other Nigerian cities, Aba, Kaduna and Umuahia, featured in the top 20.

Following Onitsha on top of the list is Peshawar, Pakistan; Zabol, Iran; Rawalpindi, also in Pakistan; before Kaduna and Aba.
“The cost for countries is enormous. Air pollution affects economies and people’s quality of life. It leads to major chronic diseases and to people ultimately dying,” says Dr. Mari Neira, director of public health in WHO.