For many people, toilets are not a particularly pleasant topic. Not so for Singaporean entrepreneur Jack Sim. He founded the World Toilet Organization to draw attention to the devastating health problems poor hygiene and sanitation are causing in many parts of the world. Claudia Blume reports from Singapore.

Toilets are Jack Sim's passion. The 50-year old Singaporean gave up his job in the construction business six years ago to found the World Toilet Organization.

It may sound like a joke, but the charity deals with serious issues. Sim says more than 40 percent of the world's population lacks access to proper toilets. He says 160 million people have intestinal worms because of poor hygiene, and one-point-six million children die of diarrhea each year - often because of poor sanitation facilities, such as pit latrines.

"A lot of the time they dig a pit, and the pit is usually deep enough until it almost touches the underground water. And the feces and urine and flush water is poured into it and it seeps through the ground to the underground water and that goes to the well water and when people drink the well water, they get diarrhea, and a lot of children die every year," he says.

The goal of his World Toilet Organization, which he says has members in 41 countries around the world, is to make clean, safe and affordable sanitation available to everyone.

Every year, the organization holds World Toilet Summits at which academics, charities and government organizations discuss ways to improve sanitation and hygiene. The next summit is scheduled for New Delhi at the end of this month.

Sim says the first step in bringing about change is to talk openly about toilets - a taboo subject for many people. "Basically, toilets do not improve because people do not want to talk about it, and the reason they don't talk about it is that when they are children, their parents taught them that if you want to be respected for the rest of your life, don't ever admit that you have a relationship with the toilet - and that is really, really wrong," he says.

The charity runs a World Toilet College in Singapore. Students from different fields, such as architects or development workers, can chose among courses ranging from toilet design to ecological sanitation.

Sim says one of the organization's most important tasks is to train people in slums and rural areas to build toilets themselves. He says he promotes the use of toilets by making them into a status symbol. "If you are defecating on the roadside you are not very respectable, but if you have a toilet then it's like you have a television or you have a hand phone. So this is a very, very important way of promoting it to them, because the poor are status-seeking people," he says.

Sim says his organization will soon open a second toilet college, in the Indonesian province of Aceh.