How it began
Peter Morgan designed the latrine in the early 1970s while working at the Ministry of Health's Blair Research Laboratory in what was then Rhodesia. The first one was built in 1973 at the Henderson Research Station north of Harare. Morgan named it the Blair latrine after Dr Dyson Blair, a former Secretary for Health who had encouraged him to study sanitation and water supply. After two years of testing, the laboratory released the design to the government in 1975. The field team was headed by Ephraim Chimbunde.
Before it existed
Conventional pit latrines suffered from flies and odors. In a 1975 experiment in Zimbabwe, an unvented pit latrine yielded an average of 179 flies per day over three months, compared with 2 flies per day in an otherwise identical ventilated latrine. Rural water supply and sanitation were treated in the country as part of primary health care.
How it works
The pit is offset so that a vertical vent pipe can stand beside the shelter. Air flows down through the squat hole into the pit and up out of the pipe, carrying odors away. Flies drawn by the smell go to the top of the pipe, where a fly screen stops them from entering. The interior is kept semi-dark, so flies that hatch in the pit head for the light at the top of the pipe and are trapped by the screen. A spiral-shaped shelter later replaced doors, giving privacy and shade without a door that could be left open.
How it spread
Between 1975 and 1980 the Ministry of Health built tens of thousands on commercial farms and at clinics, government offices and small towns. After independence in 1980 the World Bank's Technology Advisory Group visited, devised the name VIP latrine and promoted it during the International Drinking Water Supply and Sanitation Decade. It entered standard textbooks and spread to countries including South Africa, Botswana and Lesotho.
Who pushed back
The standard brick version was criticized as too expensive. It used up to six bags of cement and more than 1,500 bricks, costing as much as 80 US dollars at 1998 prices, and the government subsidy program proved unsustainable. Uptake was weaker in poorer countries such as Mozambique and Malawi, where materials were costly and a cheaper slab technology became more popular.
Where it stands today
More than 500,000 had been built in Zimbabwe by 2002, with construction peaking at nearly 50,000 in 1987. The Blair latrine remains a national standard and is taught in the school curriculum. Morgan later worked to make pit toilets more ecological, with designs such as the Arborloo and Fossa alterna.
