Keo Samon, a rice farmer in southeastern Cambodia, had no toilet in her home. There wasn’t even an outhouse or a latrine for Keo, her husband and their five daughters. 

Instead, they would defecate on land around their home, or in the rice fields.

That changed after the Water Supply and Sanitation Council, a United Nations partner, began to work with her village.

Keo’s family, along with 30 others, attended community-led awareness sessions, built simple dry toilets and joined the drive to make their village “open defecation-free”.  

“In the past, I did not know the consequences of defecating outdoors,” Keo says.

“It was simply my habit, and of others in my village. We were not aware of the importance of good hygiene. But now, I am very excited to have my latrine.”

What good does a toilet do? More than you may imagine.

Adequate sanitation prevents disease or malnutrition caused by contaminated water.

Open defecation — practised by more than a billion people around the world — is among the main causes of diarrhoea, which kills more than three-quarters of a million children aged five or under every year.  

Sanitation is also a necessary path to protection and empowerment for women and girls.

When schools lack toilets, girls stay home when they are menstruating.

And when adequate sanitation is unavailable, women and girls are forced to attend to their private needs in the open, leaving them subject to sexual abuse.    

Finally, there is the economic argument. Polluted water and poor sanitation cost developing countries about $260 billion a year — 1.5 per cent of their collective gross domestic product.

On the other hand, every dollar invested in water supply and sani-tation can bring a five-fold return by keeping people healthy and productive.  

So it is difficult to understand why, in 2013, 2.5 billion people around the world still lack access to adequate sanitation.

In today’s world, there are more people with cell phones than there are with toilets.  

Since the adoption of the Millennium Development Goals (MDGs) in the year 2000, global poverty rates have been reduced by half.

So has the proportion of people without access to improved sources of water. Two hundred million slum-dwellers live better lives, and enrolment in schools has increased dramatically.

The global mobilisation behind the MDGs has been a remarkable success that has changed the world’s approach to development for the better.

Yet, with just over 1,000 days remaining before the 2015 deadline for achieving the MDGs, we are not even close to reaching the goal on proper sanitation.

That is why I am, on behalf of the Secretary-General and the UN, launching a call to action on sani-tation as we mark the beginning of the International Year on Water Co-operation.

There are three things we can do to speed up progress on sanitation.

First, we should accelerate the elimination of open defecation — country by country, community by community, family by family.

We need to talk about the problem, not turn our heads away from a subject many of us may find uncomfortable.

Second, we need to strengthen co-operation. The water and sanitation challenge is everybody’s business, and we need everyone to play their part.

National governments need to take the lead by making commitments. Local governments can work with communities to help them to help themselves.

The private sector can invest in the health of employees and the environment. And civil-society organisations can monitor progress and advocate for solutions.

Third, we should scale up the projects that work. Simple, afford-able actions have already proved their worth.

Between 1990 and 2010, about 1.8 billion people gained access to sanitation — a significant achievement. Many countries have tackled this problem within a generation.   

Doing nothing is not an option. The social, economic and environmental cost is simply too high.

Let us commit now to end open defecation and provide adequate sanitation and safe water for all, so women and girls can live with dignity, so our children can survive and so communities can thrive.

Keo in Cambodia reports that all her family members are now using the latrine and drinking safe water.

“I ask all the families in my village to start building latrines for their use,” she says.

“This will help our village to end open defecation and bring good health for everyone, especially for our children.”

Keo has set an example. Let us follow, one community at a time. Nobody can do everything — but everybody can do something.

Jan Eliasson is Deputy Secretary-General of the United Nations.