Health and sanitation

Third World cities by Dr Greg GOLDSTEIN

In cities around the world, the living conditions of hundreds of millions of people threaten their health, impose misery and have potentially catastrophic social consequences. The manifestations of the urban crisis vary greatly among countries and regions. But hardly any large city in either developing or industrialised countries is immune. Conditions are worse for poor people, particularly in developing countries.

Urban growth has outstripped society's capacity to meet human needs, leaving hundreds of millions of people with inadequate incomes, inadequate diets and inadequate housing and services. All too often, urban development is associated with destructive effects on the physical environment and the resource base needed for sustainable development, leading to illnesses, accidents, crime and other social pathologies.

The last forty years has brought very rapid growth in both total and urban populations in virtually all countries in the South, from natural increase and rural-urban migration. Urban growth has been particularly rapid in Africa. Total population in the South grew from 1.7 billion to close to 4 billion, while urban population grew from 500 million to 1.3 billion. The South's urban population is now larger than the combined populations of Europe, North America and Japan.

In the developed countries, where population growth has slowed to very low rates, the major impacts of urban development on health and the environment result from: increased consumption of resources leading to pollution and the exhaustion of the environment's capacity to absorb wastes, changing diet, traffic jams, psychosocial problems such as drug abuse, crime, mental illness, and vandalism, and poverty. Many of their cities need to extend and replace deteriorating infrastructures and to control pollution more effectively.

In developing countries, the major impacts of urban development on health and the environment result from: rapid population growth; crowding and 'densification' of human settlements, with congestion, traffic, and increased occupation of urban land subject to landslides, floods, and other natural hazards; growing numbers of people living in extreme poverty; increasing biological, chemical, and physical pollution of air, water and land from industrialization; the increasing generation and improper disposal of commercial and domestic wastes; and the overwhelming of the financial and administrative resources of cities to provide basic infrastructure and services. Urban development has produced a pattern of health problems that includes both the diseases typical of underdevelopment, and the diseases typical of developed country cities. At the same time, the concentration of resources - economic, technological, human - in cities provides a stronger basis for action than is found in more dispersed settlements.

The experiences of some African countries illustrate the enormous changes. In Swaziland, for example, less than 1% of the 1950 population was urbanized. Today it has grown to 33%, but it could rise to 63% of the total population by the year 2025. Similarly, Mauritania's urban population may grow from 3% in 1950, to 70% by 2025, with the populations in most major cities having quadrupled between 1950 and the mid 1980s. In some cities including Dar es Salaam, Nairobi, Abidjan, Khartoum and Lagos, populations have multiplied more than sixfold.

It is estimated that one billion people across the world are living in shanty towns at the present time, and that 60% of city dwellers in developing countries will be squatters by the end of the century. In many African countries, new urban forms are developing which are different from - Western concepts of 'urban' - perhaps, not surprisingly, because urban forms reflect the economy, culture and society of which they are part. An example is the 'ruralizing' of many African cities as jobs become so scarce and incomes so inadequate, that lower and even middle-income groups increasingly grow part of their own food in or close to the city. For instance, a recent study pointed to the importance for most households in Nairobi of food they grow or produce themselves.

Both in Lusaka, Zambia's capital and largest city, and Dar es Salaam, the largest city in Tanzania, more than half of all households in some low income areas grow a proportion of their own food either on plots next to their shelters or on plots elsewhere cultivated during the rainy season; for many families this food provides a vital food supplement.

Urban health problems

There is increasing recognition that without a healthy population, sound development is not possible.

The health problems of the poor majority in African cities are generally understated because so many of the poor are not included within health statistics or health studies. The debate as to whether the rural or urban poor suffer most is one which for most nations cannot be settled, and in many ways is in any case misleading. Poverty, as a composite index of deprivation extending from command over economic resources, access to education, and social support, to control of housing and physical environment quality, remains the most significant predictor of urban and rural morbidity and mortality.

Infant mortality rates or the incidence of some of the most serious, common diseases are several times higher in poor districts when compared to city averages or to richer districts.

Virtually all the homes and neighbour hoods of poorer groups share two characteristics with serious impacts on health: the presence in the living environment of pathogenic micro-organisms (especially those in human excrete) because of the lack of infrastructure or services to remove and safely dispose of them; and crowded, cramped, housing conditions.

A lack of readily available drinking water, of sewerage connections (or other systems to dispose of human waste), of garbage collection and basic measures to prevent disease and provide health care ensure that many diseases are endemic - diarrhoea, dysenteries, typhoid, intestinal parasites and food poisoning among them. These, combined with malnutrition, so weaken the body's defences that measles and other common childhood diseases become major killers.

Most urban centres in Africa have no sewerage system at all - including many cities with a million or more inhabitants. Rivers, streams, canals, gullies and ditches are where most human excrement and household waste end up, untreated. For those cities with a sewerage system, rarely does it serve more than a small proportion of the population - typically the richer, residential, government and commercial areas. Garbage collection services are inadequate or non-existent in most residential areas; commonly 30- 50% of the solid waste generated within urban centres is left uncollected. It accumulates on streets, open spaces between houses and wasteland, causing blocked drains or contributing to serious health problems.

Crowding ensures that diseases such as tuberculosis, influenza and meningitis are easily transmitted from one person to another - their spread often being helped by low resistance among- the inhabitants due to malnutrition. It is common for poorer households to have less than one square metro of space per person in their homes, and even small rooms may be subdivided to allow multiple occupancy.

In terms of the broader city environment, problems usually centre on:

- High levels of water pollution, due to lack of a sewerage system or improper solid waste disposal. The other major cause is industrial liquid wastes, most of them dumped in contravention of regulations.

- Toxic/hazardous industrial and commercial wastes disposed of in water bodies or land sites without special provision to treat them prior to disposal (to render them less damaging), or without measures to ensure that disposal itself isolates them from the environment. - High levels of air pollution. The main contributors and their relative importance vary greatly from city to city, but include heavy industry, congested streets and poorly maintained motor vehicle engines, and (often) high levels of lead additive in petrol; thermal power stations burning high sulphur or oil; households' use of wood or coal as their main fuel, which may also cause indoor air pollution. High levels of air pollution in certain major industrial centres have been linked to a high incidence of bronchitis and asthma.

- Inadequate systems to dispose of waste water and flooding control.

There is often little or no incentive for industry and commerce to cut down polluting emissions since few are penalised and the penalties, when finally imposed, are so small as to have little deterrent effect.

The city interacts with its wider region, which usually includes large areas considered to be rural. Its inhabitants and its natural resource base usually suffer from a series of environmental impacts coming from city-based activities or city-generated wastes, for example:

- the destruction of coastal and estuary fisheries as a result of water pollution from city-based enterprises - for example as recently documented for Lake Maryut in Alexandria, the Bay of Dakar, and elsewhere;

- city water supplies taking priority over farmers' water needs for irrigation;

- air pollution arising from city-based industries damaging vegetation.

Again, at this geographic scale, there are problems of solid wastes from city enterprises - as they are dumped on poorly-prepared and -maintained landfill sites, leading to contamination of water used by farmers or rural households for their own consumption.

Inproved urban health and sanitation

The following policies and activities have been recommended by the WHO for implementation by the key players in urban health development. They encompass the following:

- development and implementation of a municipal health plan including relevant social and environmental components. This requries (a) political commitment of the city to improved health and wellbeing, and reduced inequalities in the city; (b) building-up of intersectoral or inter-agency committees at both the political and technical level; and (c) establishing collaborative links and partnerships with scientific, cultural, medical, business, social and other city institutions, using networking to gain political support and mobilise resources for technical programmes to improve health and the environment;

- strengthening of community participation in urban improvement activities, by the adoption of en 'enabling strategy' by the municipality, that emphasises 'doing wish' rasher then 'doing for' (or providing services for)

- raising awareness, through (a) public education for health (in schools, work places, mass media, etc.); (b) surveys of the existing health, social and environmental conditions in the city; documentation of intra-urban differences can be a valuable strategy to draw public attention to problems, to assist urban managers and planners in their work, and in mobilising resources;

- strengthening of environmental health capabilities, to provide environmental services in water supply, sanitation, solid waste management and pollution control, and to allow use of health impact and environmental impact assessment procedures for urban development projects

- establishment of collaborative activities and links with other cities (city networks) in order to exchange models of good practice.

The most prominent international cooperation activity in this programme is the WHO 'healthy cities' programme, which includes all of the above elements. It involves the municipal government, with participation by community organisations, and scientific, cultural, medical, business, social and other city institutions.

Preventing rapid urban growth. The limitations of control measures are recognised. However two approaches are valid. There is the need for national population policies that translate into effective family planning programmes. All people (especially women) need knowledge about family planning techniques, access to services and availability of materials. Social and economic underpinning of large families has to be addressed concomitantly with the promotion of family planning services.

There is a need for urban and rural development policies that respond to potential urban problem areas - urban areas that are growing fast - with measures that provide incentives for people, for industry, for the private sector, and for government agencies, to reduce the concentration of population in problem or potential problem areas.

G.G.