ORIGIN OF ARSENIC

Observations indicate that arsenic-rich pyrite and other arsenic minerals that give rise to arsenic pollution are rare or even absent in the sediments of the Ganges delta. Where arsenopyrite is present in sulphide ores associated with sediment-hosted gold deposits, it tends to be the earliest-formed mineral, derived from hydrothermal solutions and formed at temperatures typically of 100ºC or more. Such deposit is unknown in Bengal Basin.

The Ganges alluvial tract upstream of Rajmahal, in the state of Bihar and Uttar Pradesh does not suffer arsenic contamination on a large scale

The relatively low values of dissolved iron (0 - 0.7 mg per litre) upstream of the Ganges delta (Utter Pradesh and Bihar) indicate that the environment may not be sufficiently reducing iron and arsenic. Datta and Subramanian (1997) found concentrations in sediments from the River Ganges averaging 2.0 mg kg–1 (range 1.2–2.6 mg kg–1), from the Brahmaputra River averaging 2.8 mg kg–1 (range 1.4–5.9 mg kg–1) and from the Meghna River averaging 3.5 mg kg–1 (range 1.3–5.6 mg kg–1).

The copper belt of Bihar (India) contains small amounts of arseopyrite and the coal basins of the Damodar valley (India) contain moderate concentrations of arsenic are drained by rivers that flow far to the south of the Ganges tributary system.

ARGUMENT AGAINST NATURAL ORIGIN

It is a story about underground water: when the nectar turns into poison. When a daily task of drinking water from the handpump becomes the source of crippling disease and death. This is not a "natural" disaster - where natural arsenic or fluoride, present deep down, just happened to make their way into drinking water. It is about a deliberate poisoning. Created by successive governments and multilateral agencies: all well intentioned in their quest for safer, cleaner water supply; all investing in boring into the ground, till they brought the dark zone into the light (CSE, 13. 08. 03)

The story begins many years ago, sometimes in the 1960s and 1970s, when national governments and international agencies drew up detailed plans to provide safe water to all. They understood, rightly, that bacteria in water kills more babies than any other substance in the world. They believed the water on the surface - in millions of ponds and tanks and other water harvesting structures - was contaminated and so invested quickly in new technologies to dig deeper and deeper into the ground. Drills, borepipes, tubewells and handpumps quickly became the triumphalistic instruments of public health missions. Then the water table started to fall. Investment were made to dig deeper. And here is where the story turns.

More than three decades of application of registered and unregistered agrochemicals lead to a dramatic soil erosion in Bangladesh. To compensate for the soil's dwindling natural fertility, farmers must apply more and more fertilisers - but with the decreasing prospect that yields will increase. Bangladesh is a very sad example that a wrong agricultural policy was applied to save lives, now millions are exposed to death slowly and silently. Seed, fertiliser, pesticide and ground water power pumps have completely changed the nation. Virtually all modern seed varieties are bred prominently for one thing "high yield" since high yield means more profit.