NEW DELHI:Hand hygiene, using clean water and soap, is key to fighting coronavirus but 3 billion people in the world — 40% of the global population — live without basic hand-washing facilities at home.Flagging this fact, noted by multiple UN bodies, on World Water Day, experts on Sunday said the poor across the globe were among the most vulnerable in the face of spread of Covid-19.Reports of WHO and Unicef noted that 1.6 billion people out of the 3 billion deprived ones had limited facilities lacking soap or water while the remaining 1.4 billion had no facility at all — an indication of how the health risk due to coronavirus could be far bigger if the spread is not contained.Referring it as a “global hygiene crisis”, the UN in its factsheet said that one out of six healthcare facilities globally had no hygiene service, meaning they lacked hand hygiene facilities at points of care, as well as soap and water in toilets. “One in 10 patients get an avoidable infection while receiving care,” it said.This is a major concern in most low- and middle-income countries in Africa , Latin America, the Caribbean and Asia , including India. The UN reports said nearly three-quarters of the population of least developed countries lacked hand-washing facilities with soap and water.“Providing access to clean water is the biggest preventive health measure we can take — and this is why, on World Water Day 2020, we must make this connection. For all our sakes,” said Sunita Narain, environmentalist and director general of Centre for Science and Environment.Going by WHO’s prescribed standards where a person takes 30-40 seconds for one proper hand-wash to get germ-free hands, the New Delhi-based think-tank calculated that if each person in these days of Covid-19 needed to wash hands at least 10 times a day, a family of five would need a minimum 100 litres (2 litres per person with the tap closed while scrubbing and rinsing) every day just for hand-washing (assuming that one does not leave the tap running when one rubs hands with soap).Noting the critical water situation in India, Himanshu Thakkar, water expert and and coordinator of the South Asia Network on Dams, Rivers and People (SANDRP), said an estimated 59% of urban houses and 78% of rural houses in the country did not have access to clean water at home even for drinking.He said, “The situation is not improving rapidly as groundwater, India's main source of water, is over exploited and depleting in levels and deteriorating in quality. Moreover, the mismanagement is getting compounded under the climate change, which is the theme of the World Water Day 2020.”Narain pointed at another concern, flagging how the increased use of water will naturally lead to generation of more wastewater.“Keeping in mind the fact that 85-90% of all water used in a household gets discharged as wastewater, the more water we use, the more sewage we discharge. This, when we know that the bulk of wastewater is not intercepted, nor treated or cleaned. This means that we are adding to the pollution challenge of our waterbodies. It will mean higher cost to clean this water for drinking and it will mean more dirty water, which in turn, means more bad health,” she said.