Karachi ranks third on list of most polluted cities in world
In the list of the most polluted cities in the world, Karachi ranks third. The Air Quality Index (AQI) of Karachi was recorded at 198, making it hazardous for the health of residents. Top on the list is Calcutta and Dhaka, ranking first and second respectively. An AQI value of 50 or below represents good … Read more