Mumbai: On November 19, World Toilet Day, Jack Sim, founder of the World Toilet Organization, has a theory about why governments and people are so reluctant to talk about hygiene: it isn't cool.

"People demand a TV, not a toilet, because it is not aspirational or charismatic," said Sim, who does not hesitate to talk in graphic detail about thedangers of poor sanitation.

"Governments and people are not very receptive to being told they're dirty, that they need more toilets," said Sim on a visit to Mumbai, where more than half its 18 million residents live in slums and where the average ratio of people to toilets is 81:1.

In Mumbai, where teeming slums sit cheek by jowl with gleaming office blocks and luxury apartments, sanitation is not just a poor person's problem, said Sim, a native of Singapore.

"You are in such close proximity to slums, to people defecating and peeing in the open, that basically, you are walking in someone's poo," Sim said.

But the sight of people defecating by railway tracks or even by the roadside is so common that residents turn a blind eye to the problem and do not give it the seriousness it deserves.

"You see it long enough, and there is a basic acceptance that dirt is normal. But being repulsed by dirt, it's smell and sight is a natural defense against disease," Sim said.

With better sanitation in India, where thousands die of diarrhoea and gastro-intestinal disease, people will not fall ill so much, can work better and get out of poverty, Sim said.

In India, Sim's outfit, which he calls the WTO, works with several NGOs that build and maintain public toilets. But they need to think beyond just building more toilets that are seldom maintained and get taken over by encroachers, he said.

WTO, along with consumer goods maker Hindustan Unilever, has launched a pilot programme on some premium Rajdhani Express trains to keep the toilets clean in return for advertising space.

"This is an example of market factors solving a big problem," said Carolyn Jones, global hygiene manager at Unilever.

"It is a sensitive issue, but a serious one that has to be a shared responsibility of the government, companies and people."