Toxic compounds, which affect human cells, were found at the Ghazipur site Toxic compounds, which affect human cells, were found at the Ghazipur site

A huge environmental hazard looms over the Capital as the city's three landfill sites - Okhla, Bhalswa and Ghazipur - continue to accumulate garbage beyond their shelf life.

A study done by Jawaharlal Nehru University's Department of Environment shows that the groundsoil of these three sites harbour organic pollutants exceeding the permissible limits by up to 158 times.

These sites were found to be high on compounds like aliphatics, terpenoids, benzenes, ketones, pharmaceuticals and phthalates which do not degrade with time, enter the food chain quickly and cause a variety of health issues such as hormone disruption, reproductive disorders, learning disabilities, heart diseases, diabetes and cancer.

Additionally, Ghazipur was found to accumulate compounds which are more cytotoxic, that is human cell killing, in nature. On the other hand, Okhla contained more of genotoxic compounds which cause alteration in cell DNA. The researchers fear that the contaminated liquid emanating from the garbage, called leachate, will pollute the groundwater beyond cure. This can prove to be disastrous for large populations residing near these three landfill sites which use groundwater. It will also further pollute Yamuna which runs along the course of these three sites.

Pooja Ghosh, a research scholar and co-author of the study, said, "The national Capital produces more than 9,000 tonnes of Municipal Solid Waste daily. The Ghazipur, Okhla and Bhalswa sites are all unengineered, that is lacking a baseline, and oversaturated with waste. Based on amount of rainfall, age of the landfill as well as waste composition and degradation stage of waste, the sites continuously leak contaminants in the groundwater."

"Samples of leachate were collected at the three landfill sites - Ghazipur, Okhla and Bhalswa - in the summer of May 2012. Several chemicals were found in leachate that may act in a synzsynergistic and additive manner to cause toxic effects on organisms such as aquatic species in Yamuna and the human population living alongside the sites."

All the samples were characterised by dark colour, unpleasant odor, alkaline pH, high conductivity and relatively high concentrations of organic matter. Unfortunately, no standard maximum allowable discharge limit for landfill leachate is there in India, so the limits set by developed countries such as Germany were used as a guideline in the present study. Leachate samples were found to exceed the permissible limits of leachate discharge for iron and chromium. High concentrations of cadmium and copper were also found at Okhla and Ghazipur respectively.

Co-author and JNU environment department dean Indu Shekhar Thakur and Asmita Gupta said, "The three sites must be closed immediately and further sites engineered and lined appropriately."