Creating idols for Durga Puja
Thudding hammers, buzzing saws, and classic Bollywood and Bengali songs fill the many lanes and by-lanes of Kumartuli, the abode of potters whose hands have molded gods for almost three centuries.
An array of studios, with rows of idols jam-packed in various stages of completion line both sides of the lanes creating a maze one can get lost in. The air is filled with the scent of wet clay and generations’ worth of craftsmanship. This traditional potters’ neighborhood makes more than 13,000 idols annually. Most are part of Hindu festivals, the largest one being the Durga puja festival.

Carcinogens in the Hooghly River
The final rites of these idols include immersion into the water. A 1993-95 study found around 15,000 idols were immersed in the Hooghly River. In 2021, the number of immersions had dropped by 30%. However, environmentalists in West Bengal call for zero idol immersions and alternatives as studies continue to find carcinogenic and nonbiodegradable materials in the state’s water bodies.
A 2014 research study found that the paints used to color idols contained various heavy metals and a few colors had potent carcinogens. The floating materials that the decomposing idols release in the rivers and lakes damage the water ecosystem and cause stagnation by blocking the natural flow of water. This adversely affects the marine ecosystem and the people reliant on these water sources for their livelihood.
Fighting eco-unfriendly rituals
Ambarnath Sengupta, a retired coal expert, has worked tirelessly to bring the water pollution problem to the attention of the authorities. He shows email printouts—sent to the National Green Tribunal (NGT), the Mayor of Kolkata, and the Supreme Court among many others — court judgments, newspaper clippings, and research. A researcher, environmentalist, and devotee who is against the rigidity of rituals, Sengupta has spent the last few years focused on environmental problems caused by religious practices.
The eighty-six-year-old lives in a small apartment, attended by a caretaker. Anxious about being targeted by various parties involved in the Durga Pujas he is challenging, Sengupta makes sure that the security at the gates to his home enters visitor details in a register. With shaky hands, he videotapes each caller’s purpose for their visit on his little digicam.
“For idol immersions, there is only Sengupta,” he emphasizes, reiterating that he is the only person giving this issue the attention that it deserves.
Eco-friendly idols
According to Kartik Pal, secretary of the union of the artisans in Kumartuli and an artisan himself, Puja-organizing committees hope to win awards and maintain the standards of the festival since it received the UNESCO heritage tag. The idol makers have been tasked with making eco-friendly idols.

According to Pal, the idol-making process starts with a wooden frame that is wrapped with straw. It is covered with a mixture of clay and rice husk and left to dry. The cracks are filled with waste cloth materials and again smoothed with clay. The idol is then covered with a layer of fine-grained clay for a smooth finish and polished look. The heads are made separately, attached to the frames, and then left to dry. Finally, the artisans apply a layer of tamarind seed paste and water-soluble white paint as the base coat before painting.
Since the artisans mostly use natural elements that disintegrate in the water, Pal says the idol makers are following sustainable practices.
More idols = more pollution
However, with the increase in the scale of the Durga Puja festival and other smaller festivals catching up, the number of idols has been rising said Saikat Kumar Basu, Executive Research Director at Lethbridge. He works for and writes about environmental conservation in Kolkata. As a result, pollution has increased in local bodies of water, especially the river Ganga with significant amounts of decorative materials such as aluminum foil, plastics, polymers, and thermocol, adding to the debris.

Alternatives to immersion
Sengupta suggests alternative ways to undertake the final rites for the idols. One remedy is “Bhumi Shodhan,” a process of spraying water on the idols and then burning them in an alternate space rather than using crucial water bodies. He also suggests artificial ponds for immersion or a bucket for small idols at home.
“This process is like repaying the loan to the Earth with interest,” Sengupta said.
In 2018, the State of West Bengal set forth a ‘Procedure for Immersion of Idol’ after pujas. The ruling complies with the judgment issued after Sengupta’s lawsuit against the state in 2016. The Procedure lists the steps to be taken during immersion by the state, the puja committees, and local authorities, with penalties in case of failure. In 2019, the National Mission for Clean Ganga released a set of guidelines to fight immersion pollution, and in 2020, the Central Pollution Control Board issued revised guidelines.
Recycling idol material
According to Pal, the Kolkata Municipal Corporation implements several recycling measures to ensure clean immersion, including deploying cranes at various spots to lift the idols out of the rivers immediately after immersion. Some places also have synthetic liners in the water so idols can be extracted before debris or paint mixes with the water.
Wood, straw, and bamboo frames are collected and resold to Kumartuli after the clay melts into the water.

A 2019 study conducted before and after immersion in six different locations at six major locations along the Hooghly in Kolkata confirmed the presence of heavy metals, indicating high pollution levels caused in river water by immersion.
After immersion, the high concentration of metals increases significantly, rising above desirable and permissible levels of drinking water standards. What concerns environmentalists is that the Hooghly River is the primary source of water for many regions in the state and that polluted drinking water is making its way into living beings through the food chain process.

Saikat Kumar Basu points out that the increasing number of smaller pujas will add to the problem.
“But the same level of monitoring and surveillance that is followed during the immersion of idols during the Durga Puja is not followed similarly strictly during the other pujas,” he said. Along with the idols, flowers, leaves, ghee, plastics, and aluminum foil are thrown into the waters, often going unnoticed unless local authorities and people take action.
Sengupta blames religious rituals for pollution and is disgruntled by the inefficient implementation of guidelines.
“We have a very conservative orthodox Hindu mindset regarding idol immersion and other religious practices,” Basu said. “And we do not want to pay any attention to the harmful negative impacts we are putting on the environment through our activities. This needs to be modified.”