India, Aug. 27 -- Despite progress over the past decade, billions worldwide still lack access to safe drinking water, sanitation, and hygiene, leaving them vulnerable to disease and social exclusion, according to a UN report released on Tuesday.

The report from the World Health Organization (WHO) and children's agency (UNICEF) issued as World Water Week gets underway, highlights persistent gaps in access, with vulnerable communities facing the greatest disparities.

Some 2.1 billion people still lack access to safely managed drinking water, while 106 million worldwide are forced to rely on untreated surface sources.

"Water, sanitation and hygiene are not privileges, they are basic human rights," said Ruediger Krech, Director of WHO's En...