‘Don’t let festival choke our lakes’

A month ahead of Gowri Ganesha Festival, a Chemistry professor from city-based MES Degree College highlighted the harm that Plaster of Paris (PoP) Ganesha idols can cause to our lakes and rivers.

At a workshop on eco-friendly Ganeshas, held at the Karnataka State Pollution Control Board premises, professor C Ananth said, “Last year, after 15 days of Ganesha visarjan (immersion), the BBMP had to extract 17 truck-loads of PoP from Sankey Tank alone.”

While the clay Ganeshas dissolve easily in water, the more popular PoP idols take over two years to completely disintegrate.

“The PoP debris settles down in the lake bed, emitting odour and colour. Most of these idols are painted with enamel or oil colours, which suspend or dissolve in the water and are hazardous to health,” he said.

Last year, the students of MES, along with professor Ananth, had taken water samples on the 16th day after the Ganesha festival from Sankey Tank. “It showed high levels of metals such as lead, cobalt, chromium and mercury,” he said.

After the 15th day, water from Sankey Tank is pumped into the Bangalore Water Supply and Sewerage Board’s line through Seshadripuram. “This then joins Vrishabhavathi valley, which is known as the most polluted river in the state. One level of clarification process is done at Kengeri, where suspended impurities in the water are removed. But most of the dissolved impurities still remain, which then reaches Cauvery river,” Ananth said.

“We need to know what we dissolve in the lakes. We have to educate people. Studies must be done to understand the Vrishabhavathi valley where vegetables are grown and cleaned.

Some of the vegetables may also have these toxic materials. Greens like coriander also absorb high levels of lead, which can be hazardous,” he said.