Pongal is a festival celebrated by Tamils all over the world and signifies the birth of Thai month or the spring season. The four-day festival begins with the celebration of Bhogi which means the end of the winter. On this day, people get rid of the old things from their houses. AIR correspondent reports that, on Bhogi festival, it is a custom to burn all the old things on this day and the day break usually is smoggy.<br />'' <br />''<span style="color: #222222;">The Tamil Nadu Pollution Control Board had appealed to the people not to burn materials which could harm the environment and create health hazard. The Board said that it is illegal to indulge in burning of rubber, tyres, chemical residues which could also affect the flight landing at airports. Arrangements have been made to monitor air quality before and after the festival at 15 places throughout the day.</span><br />