The UN head expressed concern over millions of deaths around the world annually due to poor sanitation.
Improving sanitation and building more toilets could save those lives around the world and would remove an important source of inequality, the UN said Friday ahead of World Toilet Day.
"Eliminating inequalities can start in the most unlikely of places: a toilet," said Catarina de Albuquerque, the United Nations Special Rapporteur on the human right to safe drinking water and sanitation.
More than 2.7 million people die each year due to lacking sanitation, and most of them are under five years of age, the UN expert told reporters in Geneva.
"Access to sanitation facilities around the world, more than any other service, provides a window into the vast difference between the 'haves' and the 'have-nots'," she said, pointing out that not having a toilet was almost exclusively the burden of the poor.
Only one in three people worldwide have access to suitable toilet facilities, while more than one billion people still defecate in the open, de Albuquerque said.
Lacking sanitation not only made poor people sick; it also shrank their already limited possibilities by forcing them to stay away from school and work, she pointed out.
Each year, children miss a total of 272 million school days due to water-borne or sanitation-related diseases, according to the UN.
People forced to look for a place to hide to "do their business" also often fell victim to violence, she said.
In her latest report to the UN General Assembly, de Albuquerque calls for the elimination of inequalities in access to water and sanitation.
"This is not only about ensuring the right to sanitation, but it is also critical for the enjoyment of numerous other rights, such as the right to health, the right to education, the right to work and the right to lead a life in dignity," she said.