Ethiopia came fourth on the use of "outdoor" toilets. Seven in 10 people in Ethiopia's rural areas don't use indoor toilets.

WASHINGTON: India has topped the list of top ten nations that lacks sanitary facilities. In an initiative to bring awareness to the need for adequate sanitary facilities, the "big squat" was held worldwide to coincide with the 10th annual World Toilet Day .

Here's a list of the world's worst nations in terms of people lacking access to sanitary facilities, reports The Christian Science Monitor.

1. India: 638 million The world's second-most populous nation after China, India has the world's largest number of people going outdoors. Nearly 640 million Indians, or 54 percent of the 1.1 billion population lack access to toilets or other sanitation facilities. In some states, the problem was so bad that village women started a slogan: "No toilet, no bride."

2. Indonesia: 58 million About 58 million Indonesians, 26 percent of its population, don't use toilets. Southern Asia, home to 64 percent of the world's population that still uses the bathroom in the open, has seen the practice decrease the most - from 66 percent in 1990 to 44 percent in 2008.

3. China: 50 million China has 50 million citizens going in the open. That's only 4 percent of its 1.3 billion population. More than 267 million Chinese have gained access to improved sanitation since 1990, according to the WHO.

As the Los Angeles Times recently found, China's surge in wealth is also causing a spike in toilet purchases. Nearly 19 million toilets are sold in China annually - double the number sold in America.

And six percent of the urban population - compared to 2 percent of the rural population - go in the open, according the WHO's 2010 update on sanitation.

4. Ethiopia: 49 million Seven in 10 people in Ethiopia's rural areas don't use indoor toilets. The landlocked nation on the Horn of Africa has seen minimal progress over the past two decades in increasing sanitation access, with only 12 percent of the population gaining improved services.

5. Pakistan: 48 million Of Pakistan's 177 million people, about 48 million go where they please. But Pakistan has seen incredible gains over the past two decades, with 47 million people no longer defecating in the open, according to the WHO's 2010 update on progress on sanitation and drinking water.

Read more on the Economic Times and Worldtoilet.Org