India's rural development minister is pushing a campaign on public hygiene, after a recent survey revealed that India accounts for 58 percent of the world's population practicing open defecation.
Jairam Ramesh says the revelation is a source of national shame and a "sad commentary" on society's failure to address the issue through education and better sanitation.
The government says it spends $350 million a year to build rural toilets, but some 638 million still rely on fields or quiet corners.
The UNICEF report puts China and Indonesia in second place, with each representing 5 percent of the world's 1.1 billion open defecators.
Ramesh said Sunday that filth was polluting the environment as well as public spaces, and Indian rivers had become sewers.