Better put your idols in a bucket at home

KANAK HIRANI

BANGALORE: The sacred ritual of immersing Ganesha idols in lakes is actually making an unholy mess of the environment.

A study conducted by the Energy and Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore reveals the damage to the city's lakes and the surrounding water sources when idols are immersed in any of Bangalore's lakes. These studies conducted in Amruthalli, Ulsoor, Yediur, Sankey and Rachenhalli lakes reveal the impact of eutrophication (the negative effect of broken down minerals) on surrounding water sources such as borewells, open wells, etc.

Idols are made up of clay, hay, cloth, paper, wood, thermocol, jute, adhesive material, and synthetic paints. Among these materials used in making the idols, thermocol (polystyrene) is non-biodegradable while paints contain heavy metals such as chromium, lead, nickel, cadmium and zinc. Immersion of idols after the rainy season allows the bio-degradable and non-biodegradable matter in the water bodies to settle down. The bio-degradable matter is recycled while non-biodegradable substances form sediments and enter the food chain of the aquatic ecosystem.

According to IISc scientists, since water bodies such as lakes and ponds play a prominent role in the ecosystem in recharging ground water, irrigation or domestic use, water pollution due to heavy metals is a major cause of concern. Immersion of idols after festivals are an old tradition in all parts of India. Urban settlements have limited water bodies which are accessible, so for the sake of convenience people have started using the few available lakes for the immersion of idols.

Due to ignorance about the significance of water resources in the ecosystem, idols are immersed without considering the environmental consequences or impacts, the study adds. In this context, it is necessary to raise awareness among the public about the consequences of heavy metal pollutants. Most water sources in Bangalore are sewage fed, and immersions of idols in such water bodies defeat the purpose of festivals and their sanctity.

The public is advised to use clay idols (without any paint) and immerse them in a bucket of water, which could later be used in gardens. City lakes are becoming shallow due to indiscriminate disposal of solid wastes and immersion of idols, and some of them have turned in to bogs. The water-holding capacity and natural drainage systems are altered due to accumulation of silt. This also affects ground water recharging capability, the study adds.