With over 600 million people in India or 53 per cent of Indian households defecating in the open, absence of toilet or latrine is one of the important contributors to malnutrition, a World Bank report has said.

The report that released yesterday on the eve of the first ever UN World Toilet Day, the World Bank said, access to improved sanitation can increase cognition among children.

Currently, more than 2.5 billion people worldwide lack access to toilets, one billion people practice open defecation and 600 million in India openly defecate.

"Our research showed that six-year-olds who had been exposed to India's sanitation programme during their first year of life were more likely to recognise letters and simple numbers on learning tests than those who were not," said Dean Spears, lead author of the paper 'Effects of Early-Life Exposure to Sanitation on Childhood Cognitive Skills'.

The paper studies the effects on childhood cognitive achievement of early life exposure to India's Total Sanitation Campaign, a national scale government programme that encouraged local governments to build and promote use of inexpensive pit latrines.