New arsenic theory

I was wondering what these microbes were doing fifty, hundred or centuries ago; and why this arsenic menace is localised or confined in the Bengal delta region, and other delta regions in the globe do not report such findings. What is the new catalyst to change the behavior pattern of these 'modern' microbes?

Other popular hypotheses point to the cumulative effect of the downstream Farakka dam in West Bengal, and raising of the river beds and coastal seabed in the Bay of Bengal due to deposit of billions of tons of silt for centuries. The arsenic problem occurred late, or its presence in human bodies was detected late?

The new theory is very interesting for public awareness, as a simple solution is conjectured: bring up the underground water, air it, and expose it to the sun for some time, then filter and drink.

Can the readers have some more information from informed sources?