"Due to poor sanitation, people in India face many health hazards, and in monetary terms the cost to the country for treatment of such ailments is Rs. 200 crores (Rs.2 billion) and the loss of working days due to it costs Rs.300 crores (Rs.3 billion)," Kalam said.
Addressing the World Toilet Summit here, he said: "These Rs.500 crores (Rs 5 billion) can be utilised for the benefit of economically weaker sections of society.
"Ministries like rural development, water, poverty alleviation and social justice should join hands together to provide adequate sanitation, specially the toilet system, to all Indians," Kalam said. "Dedicated work of government, corporates, NGOs and socially responsible people is very much essential."
He exhorted experts participating in the four-day summit, which began Wednesday, to develop low cost technologies so that poor people can afford them.
He said toilets in urban slum clusters and villages should be connected to a common system from where human waste can be used to produce biogas and its water can be recycled for the use in toilet complexes.
"If India wants to become a developed nation by 2020, the improvement in sanitation is a must," Kalam said.
Sanitation experts from 44 countries are in Delhi to brainstorm and draw an international roadmap to "provide toilets to all" by 2025. As many as 2.6 billion people across the world, 20 percent of them in India, have no access to toilet facilities.
While over 50 percent of Indians have no access to toilets, India aims at achieving open-defecation-free status by the end of 2012. Experts said open defection contaminates water and helps the spread of diseases like diarrhoea, which kills at least 4,900 people everyday worldwide.