Ashish Mansharamani, Abhimanyu Shrivastava | This article was first published in Down To Earth on Monday, 02 March 2020.
The media has consistently reported on cancer deaths in the Malwa region of Punjab. While a definite scientific finding on the same is awaited, there have been varying conclusions which may, at best, be speculative in nature.
But first, it is important to bring out facts which are uncontested. Studies have pegged consumption of phosphatic fertilizers in Punjab at ten times higher than the national average. For potato, the national average of consumption is 15-20 kg per acre. In Punjab it is 200 kg per acre.
Similarly, for paddy fields, the consumption is 75-100 kg per acre as compared to the national average of 10 kg per acre.
Pursuant to the disquieting reports from the area, Bhabha Atomic Research Centre (BARC) in 2013 analysed fertiliser and soil samples from the Malwa region and discovered heavy concentration of Uranium. This was specific to the phosphatic fertilizer (DAP or Diammonium Phosphate).
According to the report, Uranium concentration in DAP was around 91.77 parts per million (ppm), which was way beyond the permissible limit.
The total fertilizer consumption in India is 27 million tones, out of which about 20-25 per cent of phosphorous and nitrogen-based nutrients are dependent on imports from the United States, Jordan, Iran, Oman, China, Russia, Morocco, Israel, Lithuania and Egypt.
It is also a fact that the fertiliser industry in India does not follow all procedures and protocols essential for decontamination of imported phosphatic rock associated with traces of Uranium.
On the other hand, fertiliser industries in the US and Israel, ensure complete decontamination before use. It is understood that the decontamination process, which is expensive, is not taken into consideration by the domestic industry.
There is yet another theory which does not support the fertiliser route for Uranium ingestion through food chain, but emphasises on the geogenic factors for the possible presence of Uranium in the groundwater samples.
Presence of Uranium is widespread, and according to the United Nations Scientific Committee on the Effects of Atomic Radiation, its normal concentration in soil is between 300 microgram per kg (ug/kg) and 11.7 milligram per kg (mg/kg).
Higher concentrations of Uranium are present in certain types of soils and rocks, especially granite. All the three isotopes of Uranium (U-234, U-235, U-238) have a half-life period ranging from 0.25 million years to 4.47 billion years, indicating their relative stability.
The association of Uranium 238 in certain types of bedrock strata, coupled with a humongous half-life period leads to its high natural concentration in water. Such occurrences have been reported from Finland, Norway, Canada, USA and Greece.
In the Indian context, contamination of Uranium in Punjab’s groundwater has been a problem since the early 2000s. High levels of uranium found in the fertile Malwa region along with industrial effluents leads to a bigger problem as it contaminates the groundwater.
The presence of bicarbonates, nitrate, chloride anions and soil is calcareous since the carbonic acid created in the process enhances leaching efficiency of uranium from soils and sediments.
With no guidelines or acceptable standards by Central Pollution Control Board (CPCB) regarding amount of uranium in fertilisers produced in India, we are on a dead track. Authorities concerned need to take cognisance and invest in less expensive R&D of the decontamination process.
At the same time, it is also necessary to specify the acceptable limit of Uranium in ground water.
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