New Delhi: As the auspicious Hindu festival Durga Puja came to end on Tuesday, devotees across the country bade farewell to goddess Durga by immersing their idols into water bodies.

These immersions in ponds, lakes, rivers and sea on Vijaya Dashami left the waters polluted.

According to Mohit Roy, an expert from Bengal, immersions after the festival leave river Ganga polluted. He said that updated mitigation measures are needed to be taken up to curb pollution in the river.

“Mitigation measures are being taken but these measures need to be more updated,’ said Roy.

Meanwhile, the Bihar State Pollution Control Board claimed that hundreds of idols were immersed in the Ganga River despite the board’s appeal.

Earlier, the board requested the artisans not to use plaster of Paris, synthetic colours and non-biodegradable materials in making the idols.

Guddu Baba, who leads a movement to clean the river, said that brightly decorated idols accompanied with metal ornaments and plastic weapons were being ritualistically immersed in the river this year again with no thought for environment.

Plaster of Paris does not dissolve or disintegrate fast enough and contains gypsum, sulphur, phosphorus and magnesium. The chemical dyes and paints being used to colour the idols contain poisonous elements like mercury, zinc oxide, chromium and lead, some of the potential causes of developing cancer.