Defecation Statistics

In an article about sanitation in India, Jason Gale describes how a lady named Meera Devi rose before dawn each day, went to a patch outside her village, “pulled up her sari and defecated with the Taj Mahal in plain view.” Gale writes:

With that act, she added to the estimated 100,000 tons of human excrement that Indians leave each day in fields of potatoes, carrots and spinach, on banks that line rivers used for drinking and bathing and along roads jammed with scooters, trucks and pedestrians.

That is quite a sentence there, and I have two questions about it.

One, how was that estimate of “100,000 tons of human excrement” arrived at? What was it extrapolated from? How was the research to arrive at that figure done?

Two, given how specific Gale is about this, does that figure then not include excrement left in fields of rice or maize? Only “fields of potatoes, carrots and spinach”? Or is that detail thrown in only so that the prose seems descriptive?

I have no problems with the piece, mind you. Just in a quibbling mood, that’s all.

(HT: Nimai Mehta, who has a paper on the subject here—pdf link.)