Rampant use of prohibited synthetic materials and toxic paints in idols led to manyfold increase of heavy metal concentration in the Yamuna following idol immersion, a monitoring committee overseeing the cleaning of the river said.
After being apprised by the Central Pollution Control Board (CPCB) that idol immersion following Ganesh Chaturthi and Durga Pooja, and religious activities during Chhat Pooja cause extensive damage to the river, the panel said it "unacceptable and dangerous".
The monitoring committee has said the Yamuna is "fighting to stay alive" and it would not be possible to rejuvenate the river unless minimum environmental flow is provided as it is "virtually reduced to a trickle and remains dry in some stretches for almost nine months of the year".
The panel has proposed legal action and imposition of heavy fine against those violating the norms that led to pollution in the river.
The monitoring committee, formed by the National Green Tribunal (NGT), noted that concentration of heavy metals increased in the river due to immersion of painted and polished idols with metallic ornaments and shiny materials.
Post-immersion, the level of chromium increased 11 times from the limit (0.05mg/l) set by the Bureau of Indian Standards (BIS), while iron concentration increased 71 times from the 0.3 mg/l limit. Nickel increased one fold from the 0.02 mg/l BIS limit and lead increased two times from the 0.01 mg/l limit, the CPCB said.
The quality of the river water after idol immersion following Ganesh Chaturthi showed "unacceptable rise of levels of pollutants", the monitoring committee said, adding, "There is an urgent need to build awareness about how dangerous this can be and to show no latitude when CPCB guidelines are being defied."