GROUND WATER POLLUTION
So far as water is concerned there is a general belief and it has been experienced too that the river or tank or pond water may get polluted. In this age of chemical formations chemicals have been flowing in the drains polluting the river water after they join the river. The water in lakes and ponds is polluted by men and animals alike. Sometimes (rarely, of course) chemicals have rained too as have small fish and frogs. Thus even rain water, sometimes gets polluted. When pure water is not available and even tap water gets contaminated doctors advice to drink boiled water or go for the water that flows out of hand pump or jet system. It means ground water has always been considered pure and safe.
If there are too many or too much salts in the underground water it may be brackish. One may not relish it. Still it may not be a health hazard. But of late it was found in Denmark that the infants, especially in rural agricultural areas suffered from methaemoglobinaenia. A research found that it was because of excess of nitrates in the subsoil water. Further in vivo (in the body of plant or animal) research revealed that transformation of nitrate and formation of nitro compounds are responsible for stomach cancer. Further studies conducted by the Agency for Environment Protection in Denmark revealed that the overall mean level of nitrate concentration in that country has trebled in the last 35 years or so. According to World Health Organization even 10 p.p.m of nitrogen in the form of nitrates makes the water unfit for consumption by infants.
With the result reasons too flew from Denmark to India. Though the Changes in ground water quality are still in a nascent stage the people in European countries have become cautious about it. A study conducted by the agricultural scientists of Punjab Agricultural University (PAU) in 1987 revealed that increased and indiscriminate use of nitrogenous chemical fertilizers has been the cause of the malady. In the region of coarse textured irrigated farm land the nitrate/nitrogen levels have been found more than those prescribed by the WHO.
Punjab that supplies almost 50 per cent of the national requirement of wheat in the country has achieved great success in the green revolution during the post independence period. It is partly because of the increased use of chemical fertilizers. The farmers have been feeding the earth with nitrogen to have more yields. The per hectare use of fertilizers in the state in 71 -72 was 91.48 kg per hectare. It rose to 120.70 kg in 1985-86 and has been increasing since then. Most of this the nitrogen of the fertilizers is absorbed by the root zones. On the one hand the law of diminishing returns applies and the excess use of fertilizers is of no use, on the other the excessive amount of fertilizers enters the ground water in the region. That is how the ground water gets polluted. It is just the beginning. Still it is a matter of great concern. In such circumstances, according to Janne Forslund, a chemical engineer working with the Agency for Environment Protections Denmark, ‘widespread changes in ground water quality can be expected in the future.’ The changes are because of high dose of fertilizers that result in contamination.
Since it is just the beginning, the agricultural scientists feel that the ‘polluting context in the ground water can be reduced to acceptable’ levels with a proper water treatment.’ But this is only the curative aspect. It is rather necessary for the farmers to have a consciousness about it. It would rather be advisable to replace chemical fertilizers with the old dung manure. We have to abandon the nuclear plants. It would also be advisable to abandon the excessive use of nitrates in the form of chemical fertilizers. Let us be awake to the legacy that we leave for the coming generations