The most serious impact of the Ganesh festival on the natural environment is due to the immersion of icons made of Plaster of Paris into lakes, rivers and the sea. Traditionally, the Ganesh icon was sculpted out of earth taken from nearby one’s home. After worshipping the divinity in this earth icon, it was returned back to the Earth by immersing it in a nearby water body. This cycle represented the cycle of creation and dissolution in Nature.

However, as the production of Ganesh icons on a commercial basis grew, the earthen or natural clay (shaadu maati in Marathi) was replaced by Plaster of Paris. Plaster is a man made material, easier to mould, lighter and less expensive than clay. However, plaster takes much longer to dissolve and in the process of dissolution releases toxic elements into the water body. The chemical paints used to adorn these plaster icons, themselves contain heavy metals like mercury and cadmium.

Today the authorities have fabricated these concrete immersion pools near the rivers to allow the celebration while encouraging people to reduce the amount of pollution in the the rivers.

Still many perform the immersion in the rivers.