If you thought you are doing your bit for the environment by getting a Ganesh idol made of clay, the findings of a recent study may force you to rethink. Similar to Plaster of Paris (PoP), clay, too, can cloud water, block sunlight from entering the water body and consequently cause harm to marine life, according to a study conducted by the Maharashtra Nature Park (MNP) Society, Mahim.
According to the civic body, more than two lakh Ganesh idols are immersed during the 10-day festival in 71 natural and 27 artificial ponds across Mumbai. Devotees largely use two types of idols — those made of white clay and those of PoP, which are cheaper. The society tested idols made of clay, paper pulp and PoP in an artificial water body to get an idea of the time taken by the raw material to dissolve.
The study revealed that clay (locally known as shadu) takes almost three weeks to dissolve in water, which, although less than the time taken by PoP idols, is still capable of causing harm to aquatic vegetation and animals. “The PoP idols dissolve in nearly three to four months, while those made of paper pulp take three days,” said Avinash Kubal, deputy director, MNP Society.
Marine biologists said the toxicity of heavy metals in the colour used to paint idols, even the papier mâché ones, however, remains a problem.
“While paper pulp idols are relatively safer, lead-based paints nullify benefits,” said E Vivekanandan, scientist, Central Marine Fisheries Research Institute. As a solution, the study states four natural colours — Multani mitti, turmeric, terra cotta and poster colours — could be used. “The best option is poster colours, as their toxicity level is lower than synthetic colours,” said Kubal.