Sky lanterns can be especially hazardous to helicopters, which must remain below 500 ft while within 15 nautical miles from the centre of Mumbai's airport, according to helicopter pilot Captain RK Singh. "Any flying object can be a hazard for an aircraft or helicopter," said Captain Aatish Mishra, director of operations for Taj Airline Limited. "There needs to be some kind of control over the aerodrome vicinity, such that nothing is flown at least five nautical miles around the centre of the airport," he added.

Over the last year, the city's landscape has been littered with sky lanterns. They were primarily used only during Diwali and weddings, they can now be seen dotting the night sky almost every day, particularly on the weekends. Selling for anywhere between Rs 40 and 100, these sky lanterns are relatively inexpensive and easily accessible. 

"The national demand for sky lanterns in 2013 was less than a crore, rising between 3 and 4 crore in 2014," said Robin David, founder of the Thane-based Mirabel store that sells a variety of entirely biodegradable sky lanterns. These biodegradable lanterns are made from fire-retardant rice paper which are supported by bamboo frames and burns eco-fuel. "These lanterns are comparatively much less harmful to the environment than firecrackers," said Vidyadhar Walavalkar, a chemistry professor and general secretary of Thane-based NGO Paryavaran Dakshata Manch.

These lanterns are classified as handicraft items, so people are able to get it from whatever source. There needs to be regulation of the supply and market of these lanterns, apart from regulation of their use.

By Premji