Noida, Feb. 26 -- Despite recording some improvement in the air quality over the past three years, Noida and Greater Noida continued to remain on the top 10 polluted cities of the world, according to a report released Tuesday. According to the report by IQAir, a US and Swiss-based air quality solution company, which assessed the air quality parameters if total of 98 countries and over 600 cities, Ghaziabad was found to be the most polluted city in the world, while Noida and Greater Noida were placed fifth and ninth....