CITIES are currently growing at the rate of one million people every week and, by the year 2025, more than two thirds of the world's population will be living in urban areas, many of them suffering from poverty, poor housing, crime and ill health.

In 1950, only 30 per cent of humanity lived in cities and towns. By last year, this proportion had risen to 45 per cent. And by the year 2000, for the first time, every second person is expected to be living in an urban area, many in appalling conditions.

More than a third of the existing urban population of two billion plus lives in substandard housing, without access to piped water and proper sanitation. It is also estimated that only 2 per cent of the growing volume of waste in developing countries is treated.

The threat of mass homelessness is greatest in Asia, Africa and Latin America, where the population is growing fastest. But homelessness is also a problem in developed countries in London, life expectancy among the homeless is just 25 years.

At least 600 million people half of them children live in life threatening situations, and about 10 million die each year because of poor shelter, polluted water and bad sanitation, according to Trocaire, which represented at the Habitat II conference in Istanbul.

Habitat II is the lash in a series of UN conferences held this decade following the 1992 Earth Summit in Rio de Janeiro. Previous conferences dealt with poverty, population, human rights and the role of women.

The Istanbul conference will draw these themes together.

"The most pressing global environmental, economic and social issues we will face in the next century will be in cities," said Dr Wally N'Dow, secretary general of the conference.

Homelessness and poor housing conditions are at the root of all these problems."

But although urban areas have the resources to solve the housing problem, given that they account for between 50 per cent and 80 per cent of most developing countries' gross national product, he said waste and mismanagement "cripples the effort".

Habitat II's Global Report on Human Settlements also singles out poor city management. "Urban poverty results because in many countries, national and local governments cannot plan for the population increases and fail to provide the required infrastructure, services and jobs."

The report advocates a stronger role for the private sector as well as citizen groups, community organisations and other NGOs (non governmental organisations) in tackling the crisis, arguing that it would be "unrealistic to expect that governments alone could solve the housing problem".

"Massive urbanisation is the only way the world can survive the massive population increase," according to one of the report's main authors. Despite the problems cities offer higher life expectancy and lower absolute poverty than rural areas.

Dr Mathias Hundsalz, who coordinated the report, said low cost housing was a "particularly sound investment" for developing countries, because of its spin off effects in stimulating the economy. He also pointed out that "informal" housing builds six times more per dollar than standard housing.

"Much of the problem in providing housing in the developing world stems from excessive building regulations and codes," the Habitat report says, adding that the community contracts system in Sri Lanka was an enlightened approach to upgrading squatter settlements in partnership with local people.

Through this system, the residents transform slums into well maintained communities by building their own infrastructure footpaths, drains, wells, toilets and other basic necessities. Maintenance and repair is also easier because the people who do the work reap the benefits.

In her address to the Istanbul conference yesterday, Ms Liz McManus, the Minister of State for Housing and Urban Renewal, said the overall aim of the Government's housing policies was that every household would have "an affordable, good quality dwelling in a good environment".

For those who could not afford to buy homes, there were social housing schemes and rent subsidies. In dealing with the problem of homelessness, she said, the policy was not only to provide accommodation but also to "prevent people entering the homelessness cycle in the first place".