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Rapid Urbanisation: Major Threat to Health and Environment 15 June 2000 by Tinashe Madava Unplanned rapid urbanisation has been identified as a health hazard in southern Africa leading to conditions that spread serious diseases. These diseases stem from environmental problems such as contaminated water, poor sanitation, smoke-polluted indoor air and exposure to mosquitoes, along with other examples of crowded living conditions. According to a United Nations Environment Programme (UNEP) report, Global Environmental Outlook 2000, these environmental health problems in developing countries are now exacerbated by emerging problems of industrial and agricultural pollution. Chemicals used in both primary sectors are major factors in causing and worsening tuberculosis, bronchitis, heart disease, cancer and asthma. Increased exposure to chemical health risks in urban areas is particularly harmful to children and pregnant women. Most African cities were developed as colonial administrative and trading centres rather than industrial and commercial centres equipped to support large populations. As a result, well-serviced expensive city centres are often surrounded by underdeveloped and inadequately serviced settlements supporting most of the population. The quality of housing and services varies greatly. Urban authorities have been unable to keep up with the explosive growth of squatter communities and shanty towns. In Zambia, the most urbanised country in the region, water-borne diseases such as cholera and dysentery are prevalent due to lack of access to clean water and bad sanitation. More than half of the Mozambican urban population lives in unsanitary and unhealthy conditions and the levels of urban unemployment are extremely high. The unhealthy conditions are putting a huge strain on the country's health system. In Malawi, the urban population increased from five percent in the 1960s to 13 percent in 1995. Three-quarters of this urban population resides in the major urban centres of Blantyre, Lilongwe, Mzuzu and Zomba. The urban growth rate is currently estimated at 5.6 percent annually. The poor are often cramped in inadequate housing along floodplains or other areas that are vulnerable to pollution because that is the only place where they can afford to rent or build accommodation in urban parts of Malawi, South Africa, Zambia and Zimbabwe, says a report by the International Institute for Environment and Development (IIED). Stream bank cultivation is now rampant around southern African cities and towns as people seek to counter the effects of poverty resulting in contamination of water sources by fertilizers and pesticides applied in these small, unplanned farm plots. According to the UNEP report, nearly half of the world's population will live in urban centres by the end of the 20th century. Currently, 30-60 percent of the world's urban population are in low-income countries, and lack adequate housing with sanitary facilities, drainage systems, and clean piped water. Malaria and the dengue fever are some of the common diseases spreading as a result of unplanned urbanisation. The two primary mosquitoes causing these diseases have adapted from their natural forest environments, where they breed in tree holes containing rainwater, to the urban environment where they breed in drains, water cans, discarded tyres, pots and bottles. The quality of air is also affected by the industrialisation that occurs with urbanisation. Air pollution levels are neither monitored nor controlled in most cities in Africa, but while air pollution is still low compared with other areas, it is becoming a problem at local levels, especially in major cities. "The main sources of air pollution are found in urban areas and major developments such as mines and industries. Burning of fuelwood, fires, exhaust fumes from vehicles and the use of coal in factories cause air pollution," states the book, Water in Southern Africa published by SADC, IUCN and SARDC. In 1997, UNEP warned that air pollution was emerging as a major problem in South Africa and Zimbabwe in areas where energy use and industrial development are essentially based on coal. The quality of rain reflects broadly the state of atmospheric pollution in the region. One of the more damaging products of such pollution is acid rain which is caused by sulphur dioxide set free in the atmosphere where it dissolves in the moisture to form sulphuric acid. Acid rain damages soil, plant leaves and water with a consequent ill-effect on human health. According to Water in Southern Africa, examples of sources of sulphur emissions to the atmosphere are the copper/nickel smelters in Selibe Phikwe in Botswana and Tsumeb in Namibia. Due to these many environmental factors, areas settled by the urban poor are often fragile, and the concentration of population contributes to the degradation. Due to the rapid urbanisation, infrastructure designed for specific population levels breaks down under the strain of trying to serve too many. Since urbanisation has adverse effects on the environment and preventing it is next to impossible, slowing the rural to urban drift by developing rural centres would allow the latter to enhance their employment capabilities. Such a move will have to be complemented by sound economic policies that discourage rural-urban drift. This will reduce the strain on the services and infrastructure in urban areas and alleviate environmental degradation. (SARDC)
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