WASHINGTON: 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 on Monday 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.

"This is important news -- the study suggests that low-cost rural sanitation strategies such as India's Total Sanitation Campaign can support children's cognitive development," Spears said.

The results also suggest that open defecation -- going outside without using a toilet or latrine -- is an important threat to the human capital of developing countries and that a program accessible to countries where sanitation development capacity is lower could improve average cognitive skills.

"Open defecation lies at the root of many development challenges, as poor sanitation and lack of access to toilets impact public health, education, and the environment," said Jaehyang So, Manager of the World Bank's Water and Sanitation Project.

A World Bank working paper released earlier this year found that children exposed to more fecal germs don't grow as tall as other children with less exposure.

Studies have shown physical height is an important economic variable reflecting health and human capital.

However, differences in average height across developing countries are not well explained by differences in wealth, according to the report.

In particular, children in India are shorter, on average, than children in Africa who are poorer, on average, a paradox called "the Asian enigma," which has received much attention from economists and studies indicate a 5 year-old girl in India to be around 0.7 cm shorter than her counterpart in Sub-Saharan Africa.

"Within the triad of causes, food, care and environment, these papers provide additional evidence that inadequate sanitation is one of the important contributors to malnutrition, particularly in India," said Bert Voetberg, Acting Sector Manager, South Asia Health, Nutrition and Population.