Have you heard of World Toilet Day? It's a real thing, established by the United Nations on Nov. 19 as a way to remember the importance of sanitation and clean water -- and all the people who don't have it.

According to the World Bank, 2.5 billion people -- roughly 37 percent of the world’s population -- don't have access to safe sanitation. Open disposal of human waste is one of the main causes of diarrhea, which results in more deaths per year than HIV/AIDS and malaria combined, including 750,000 children under the age of 5.

In Latin America, 120 million people lack access to a toilet and the infrastructure to keep waste from seeping into their drinking water. The problem is even more noticeable outside of cities. One-third of Latin Americans who live in rural areas dispose of their waste in the open. The number drops to 13 percent in urban areas.

These numbers contrast wildly with cell phone penetration, which has surpassed 100 percent. There's an average of 107 mobile phones per 100 people, according to a World Bank report.

“In urban areas, the [sanitation] coverage is similar to other up-and-coming countries, but in rural areas, the situation is similar to the poorest countries in the world,” Ivo Imparato, World Bank sector leader in sustainable development, said.

What's surprising is that Latin America has taken strides forward in many others aspects. For the first time, Latin America has more middle class citizens than poor. In the past decade, more than 70 million people rose over the poverty line and 50 million joined middle class, thanks to the sustainable public policies and steady economic growth.

Latin American leaders signed a compromise to the UN Millennium Development Goals to bring safe sanitation to 90 percent of citizens by 2015, but it doesn't look promising. By 2011, only 82 percent had disposal services, and experts think reaching the goal is complicated, at best.

Lack of sanitation services isn't only a high life cost -- it also has worrying economic implications.

In Nicaragua, for instance, where half the population lacks access to toilets, estimates suggest that $95 million is lost every year because of it. The World Bank states that for every dollar invested in drinkable water and sanitation, countries would save $34 in healthcare to solve diseases derived from a lack of clean toilets.