Ganesh Chathurthi, a much-awaited event in the Hindu calendar, is celebrated with great pomp especially in Western India. The reason could be that freedom fighter Bal Gangadhar Tilak used this festival in the 1890s to arouse the nationalistic sentiments of locals and bring all factions together against the reigning British. This is probably how the festival transformed from being a private clebration to a grand public event. 

 

Come September, and the streets of Mumbai and several other towns and cities in the region dazzle in revelry. Towering Ganesha idols are placed at every street corner complete with regular pujas and aartis. The 11-day festivities culminate with the grand ‘visarjan’ when the the ‘Ganpati Bappas’ are immersed in the sea after parading them across the entire city one last time. 

 

We all stop to gaze at the mighty beauties, but, in most cases, fail to see what’s underneath. 

 

 

The towering idols are moulded using calcium sulfate hemihydrate, or what we know as Plaster of Paris (PoP). When these PoP idols are immersed in water, they change back into their constituent form, namely gypsum. These moulded gypsum giants take months, if not years to degrade completely compared to their eco-friendly clay variants. In addition to the very long degradation time, these idols also increase the waters’ hardness. 

 

As the idols got bigger and the orders multiplied, sticking to natural colours became more difficult and less economical. Enterprising contractors began using bright and shimmery synthetic paints similar to industrial grade paints, which are usually laced with heavy metals such as cadmium and lead. When the idols are immersed in the sea after the festivities, the chemicals slowly mix with the sea. These chemicals have a tendency to spread over larger surfaces and as a result, micro as well are macro organisms near and far are at high risk of heavy metal poisoning. 

 

Unfortunately, it does not stop here.

 

While some organisms find it difficult to manage the chemical load, others accumulate the toxic materials in their body in what is known as bio-accumulation. Guess where these bio-accumulated toxic chemicals end up! They take the long route and enter into humans when fish and other marine organisms from polluted waters are consumed. It isn't just the paint but also the accessories accompanying the idols that are a huge cause of concern. Along with the idols, decorative cloths, plastic ornaments and synthetic embellishments are dumped in the lakes and seas, increasing the non-degradable solid load. 

 

Despite it being a recurring occurrence, there aren’t many studies to pin the negative environmental impacts to the mindless dumping that follows the festivities. A compilation from Toxics Link shows that a 2001 study revealed an alarming increase in the presence of heavy metals following immersions in Hyderabad’s Hussainsagar Lake. Levels of arsenic and mercury were found to be much higher than the range prescribed by the ICMR and BIS [2].