The Central Pollution Control Board released a list of air pollution levels on Tuesday in Indian cities. Uttar Pradesh's Ghaziabad with a poor AQI of 261 was the most polluted city in India. This was followed by UP's Noida (251), Haryana's Bahadurgarh (229), Haryana's Rohtak (221), Haryana's Gurugram (216), Delhi (211) and UP's Hapur (204).