Abstract
As a result of rapid urbanization in a context of economic constraints, the majority of urban residents in sub-Saharan Africa live in slums often characterized by a lack of basic services such as water and sewerage. Consequently, the urban poor often use inexpensive pit latrines and at the same time may draw domestic water from nearby wells. Overcrowding in slums limits the adequate distance between wells and pit latrines so that micro-organisms migrate from latrines to water sources. Sanitary practices in these overcrowded slums are also poor, leading to contamination of these wells. This study sought to assess sanitary practices of residents of a Kenyan urban slum and fecal contamination of their domestic water sources. This cross-sectional study involved 192 respondents from Langas slum, Kenya. Forty water samples were collected from the water sources used by the respondents for laboratory analysis of coliforms. Of these 40 samples, 31 were from shallow wells, four from deep wells, and five from taps. Multiple-tube fermentation technique was used to enumerate coliform bacteria in water. The study found that most people (91%) in the Langas slum used wells as the main source of domestic water, whereas the rest used tap water. Whereas most people used pit latrines for excreta disposal, a substantial percentage (30%) of children excreted in the open field. The estimated distance between the pit latrines and the wells was generally short with about 40% of the pit latrines being less than 15 m from the wells. The main domestic water sources were found to be highly contaminated with fecal matter. Total coliforms were found in 100% of water samples from shallow wells, while 97% of these samples from shallow wells were positive for thermotolerant coliforms. Three out of the four samples from deep wells were positive for total coliforms, while two of the four samples were positive for thermotolerant coliforms. None of the samples from taps were positive for either total or thermotolerant coliforms. Because the presence of thermotolerant coliforms in water indicates fecal contamination, facilitated by the proximity between the wells and pit latrines, the study suggests that the pit latrines were a major source of contamination of the wells with fecal matter. However, contamination through surface runoff during rains is also plausible as indiscriminate excreta disposal particularly by children was also common. Owing to the fecal contamination, there is a high possibility of the presence of disease pathogens in the water; thus, the water from the wells in Langas may not be suitable for human consumption. To address this problem, treatment of the water at community or household level and intensive behavioral change in sanitary practices are recommended. Efforts should be made to provide regulated tap water to this community and to other slums in sub-Saharan Africa where tap water is not accessible. However, more sampling of different water sources is recommended.
Keywords: Water, Water quality, Sanitation, Sanitary practices, Coliforms, Contamination, Slums, Urban poor, Poverty, Urbanization, Africa, Kenya
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INTRODUCTION
Rapid urban growth in a climate of economic constraints has resulted in the majority of residents in Africa’s large cities, and an increasing proportion of Africans overall, living in overcrowded slums and shantytowns. In these slums and shantytowns, health conditions and livelihood opportunities are poor.1–3 Available evidence indicates that the poor urban residents of Africa exhibit higher morbidity, have poor access to health services, and consequently exhibit higher mortality rates than residents of other areas including rural residents.4–8
The situation in Kenya is similar to other situations in Africa. The proportion of urban population in Kenya nearly doubled between 1980 and 1998, increasing from 16 to 31%.9 Rapid urbanization amid economic degradation in Kenya has resulted in an increased proportion of people living in absolute poverty in the urban areas.10 Therefore, poverty has increasingly become a crucial urban problem in Kenya leading to mushrooming of informal settlements in the urban parts of Kenya where the urban poor find shelter. This has overwhelmed the environmental health resources in urban areas. Because of their illegal status, residents of informal settlements in Kenya do not receive government services such as water, drainage, sewerage, and rubbish collection. Consequently, informal settlements are characterized by poor environmental conditions that predispose their inhabitants to poor health outcomes.4 Evidence shows that children of poor families in urban areas of Kenya exhibit poorer health conditions than their rural counterparts. According to a report by African Population and Health Research Center (APHRC) in 2002,4 infant and child mortality risks are particularly higher in the slums of Nairobi than those observed in other urban areas and in rural Kenya. For instance, the under five mortality was 35% higher among slum residents in Nairobi than among the rural population in Kenya. The report attributes these patterns to poor water and sanitation in these slum settlements.4
An adequate supply of safe drinking water is universally recognized as a basic human need. Yet millions of people in the developing world do not have ready access to an adequate and safe water supply. By 1996, the number of people without access to safe water in urban areas was rising sharply in developing countries as a result of rapid urbanization, much of which was occurring in peri-urban and slum areas.11 Because the United Nations projects a rapid population growth in urban areas between 2000 and 2030,12 access to safe drinking water and adequate sanitation in urban areas is likely to worsen unless there is a drastic policy change to cater to the needs of the urban poor.
Human excreta and the lack of adequate personal and domestic hygiene have been implicated in the spread of many infectious diseases including cholera, typhoid, hepatitis, polio, cryptosporidiosis, ascariasis, and schistosomiasis. It is estimated that one-third of deaths in developing countries are caused by the consumption of contaminated water and on average as much as one-tenth of each person’s productive time is sacrificed to water-related diseases.13 The World Health Organization estimates that 2.2 million people die annually from diarrhea diseases and that 10% of the population of the developing world are severely infected with intestinal worms related to improper waste and excreta management.14,15 In Kenya, diarrheal diseases are among the major illnesses affecting children of the slum residents. According to the report by APHRC in 2002, prevalence of diarrhea was 32% among children below 5 years of age in the slums, which is double the rate for Nairobi and the national average.4
Where ground water is used as a source of domestic water, use of pit latrines is not recommended because the two are incompatible unless the water table is extremely low and soil characteristics are not likely to contribute to contamination of ground water. Where they coexist, although it is difficult to give a general rule for all soil conditions, the commonly used guideline is that the well should be located in an area higher than and at least 15 m from the pit latrines and should be at least 2 m above the water table. Available evidence shows that increased lateral separation between the source of pollution and groundwater supply reduces the risk of fecal pollution.16 Coexistence of on-site sanitation and use of underground water has in the past been mainly confined to the rural areas where there is adequate land to allow for adequate distance between pit latrines and shallow wells. With the rapid urbanization and rapid expansion of slum settlements in sub-Saharan Africa, on-site sanitation and underground water are used in some urban areas because they are affordable options in the absence of government-supplied services. However, the congestion in the urban slums does not allow for adequate distance between the wells and the pit latrines, which allows micro-organisms to migrate from fecal contents into the underground water sources. Furthermore, poor sanitary practices (for example, disposal of human excreta) in these slum areas lead to contamination of water and consequently water-borne diseases. It is in this context and in the context of high levels of diarrheal diseases in the urban slums in Kenya that this study sought to assess the sanitary practices and the fecal contamination of domestic water sources in an urban slum in Eldoret, Kenya.
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STUDY CONTEXT
The study was conducted between January and June 1999 in Langas, an urban slum in Eldoret municipality, Kenya, less than 10 km from Eldoret town. Eldoret town is located in the Rift Valley Province, about 330 km north west of Nairobi. Eldoret, the headquarter of Uasin Gishu District, is one of the fastest growing urban areas in Kenya. Langas falls under high density, low-income areas of the Eldoret municipality. It is divided into four administrative blocks that are further subdivided into about 2,500 plots. Each plot (1/8 of an acre) has between one and 30 households each with an average of six occupants. Settlement in Langas began in 1965 and at the time there were no basic services. Early settlers dug shallow wells for their water needs.17 The water table is high, and this raises the possibility of ground water contamination where on-site sanitation systems are in use.
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METHODOLOGY
A cross-sectional study design was used and a sample of 192 households1 was selected through multistage sampling technique as follows: two out of the four administrative blocks were randomly picked and from the two blocks, 192 plots were picked. From each of the selected plots, one household was selected to participate. The 192 households were selected as follows: starting