Delhi is one of the most polluted cities in the world. Its air quality is often in the hazardous range, even indoors. 

Although his doctor has advised him to leave the city, Kamal Meattle, the emeritus chairman of the Paharpur Business Center, decided to stay and make it his mission to clean the air indoors with the help of plants. His method has become so successful he has given TED Talks on it. 

Tushar Batham from Chakr Innovation also found a way capture toxic exhaust waste from diesel generators and convert it into printable ink.