Gao Shenghua, director of Shanxi Provincial Committee of Patriotic Health Campaign, says the neglect of toilets is not just an issue of personal hygiene, but a challenge to public health. A recent case was the outbreak of cholera in southern China's Hainan Province late October.

When torrential rain hit Xinying Town of Danzhou City, 51 cases of cholera were reported. A major reason, according to Bai Zhiqin, the head of Hainan Provincial Department of Health, was that villagers did not build sanitary toilets in the village and the water was polluted when the rainy season arrived.

To help the sanitation, UNICEF launched a pilot program aimed at the rural areas of northwestern China in 1996, with a focus on building a new type of double-urn latrines.

The science behind this type of toilet is quite simple, but it is effective, says Lei. The first urn, filled with water, is used for storing dung. Within three months, bacteria carried by dung are nearly all killed in an anaerobic environment, and the dung will be automatically transferred to the second urn through a tunnel linking the two.

Then, the dung in the second urn continues the process of fermentation before eventually being disposed of.

Wang Xianzhong, one of the pilot program's beneficiaries, is happy to see that he is no longer bothered by flies and the new toilet no longer smells badly.

Apart from a cleaner environment, the fermented dung in the second urn can be used as high-quality organic fertilizer.

Clean environment

Li Tuying, an orchardist in Zhanghu Village, Jinzhong City, says the fermented dung complements the chemical fertilizers she buys on the market. On average, she spends 4,500 yuan (US$658) per year on 10 tonnes of fertilizer - the fermented dung can make up to 600 kilograms of organic fertilizer.

Another part of UNICEF's pilot program is the emphasis on health awareness, as UNICEF integrates the construction of toilets with clean water and personal hygiene under its WES (water, environment and sanitation) model.

"Now, everyone in my village has accepted the idea that washing hands with soap is an effective means to prevent communicable diseases," says Wang.

In the past decade, UNICEF's practice was gradually absorbed into the policy-making process at the top level. Starting from 2007, the central government of China decided to improve sanitation in the rural areas by renovating the old-style toilets into five new varieties: double-urn, three-chamber, bio-gas, urine-diversion and water-flushed toilets.