Project – Assessment of Environmental Sanitation Practices and the Prevalence of Diarrhoeal Diseases among Residents of Selected Communities in Lagos State

CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

Environmental sanitation is an important component of public health because the physical environment in which people live, work and interact can either protect or expose them to disease. Environmental sanitation broadly encompasses practices and services directed toward the safe management of human excreta, solid waste, wastewater, drainage, household cleanliness, food hygiene and other environmental conditions that influence human health. Adequate sanitation prevents human contact with disease-causing organisms and contributes to healthier and more sustainable communities. The World Health Organization (WHO) emphasizes that poor sanitation is associated with the transmission of diarrhoeal diseases, cholera, dysentery, intestinal worm infections and several other health conditions (WHO, 2024).

Diarrhoeal diseases remain a major public health problem globally, particularly in low- and middle-income countries. Diarrhoea is generally characterized by the passage of three or more loose or liquid stools within a day or more frequently than is normal for an individual. It is usually caused by gastrointestinal infections involving bacteria, viruses or parasites and can be transmitted through contaminated water, contaminated food, inadequate sanitation and person-to-person contact associated with poor hygiene practices (WHO, 2024). The disease can result in substantial loss of water and electrolytes, dehydration, nutritional deterioration and, in severe cases, death, especially among young children, older adults and individuals whose immunity is compromised.

The importance of diarrhoeal diseases to public health is demonstrated by their continuing contribution to global morbidity and mortality. The WHO reports that diarrhoeal disease remains the third leading cause of death among children aged 1–59 months and that hundreds of thousands of children under five die from diarrhoea annually. The disease is also a leading contributor to childhood malnutrition because repeated episodes can interfere with nutrient absorption and increase nutritional requirements (WHO, 2024). This means that diarrhoeal disease should not be viewed simply as an episode of gastrointestinal illness but as a condition with implications for child survival, nutritional status, household expenditure and community development.

The relationship between environmental sanitation and diarrhoeal disease is strongly established in public health literature. Human faeces may contain pathogenic microorganisms, and when sanitation systems are inadequate, these organisms can contaminate soil, water, food and household surfaces. Individuals may subsequently become infected through ingestion of contaminated water or food, contact with contaminated environments or inadequate hand hygiene. Prüss-Ustün et al. (2014), in an analysis covering 145 countries, demonstrated the considerable burden of diarrhoeal disease attributable to inadequate drinking water, sanitation and hand hygiene in low- and middle-income settings. Their findings reinforce the importance of WASH interventions as a major strategy for preventing diarrhoeal diseases.

The pathways through which inadequate sanitation contributes to diarrhoeal disease are numerous. Open defecation, poorly maintained toilets, leaking septic systems, overflowing sewage, indiscriminate waste disposal and contaminated drainage channels can create opportunities for faecal organisms to enter domestic and community environments. During rainfall, improperly disposed waste and human excreta may be washed into drainage channels, surface water and other locations used by residents. Where households subsequently use contaminated water for drinking, cooking or washing, the likelihood of disease transmission increases. WHO (2023) identifies faecally contaminated drinking water as an important route for transmission of diarrhoea, cholera, dysentery and other water-related diseases.

Safe drinking water is therefore an essential component of environmental sanitation. Access to a water source alone does not necessarily guarantee protection from diarrhoeal diseases because water may become contaminated during collection, transportation, storage or household use. WHO (2023) notes that microbial contamination of drinking water by faecal material represents one of the greatest threats to drinking-water safety. The organization further emphasizes that safe and sufficient water facilitates good hygiene practices and reduces the risk of diarrhoeal diseases. Thus, assessment of sanitation practices should consider not only the presence of toilets and waste-disposal facilities but also the availability, quality, handling and storage of domestic water.

Sanitation is equally important because the safe containment and disposal of human excreta interrupts the transmission of faecal pathogens. According to WHO (2024), poor sanitation is linked with diarrhoeal diseases such as cholera and dysentery and also contributes to malnutrition and other health problems. Although global sanitation coverage has improved, billions of people still lack safely managed sanitation services. The persistence of inadequate sanitation indicates that the availability of sanitation infrastructure does not automatically translate into effective sanitation behaviour; communities must also use, maintain and manage available facilities appropriately.

Hand hygiene represents another important dimension of environmental sanitation. Hands can become contaminated after defecation, cleaning a child after defecation, handling waste, touching contaminated surfaces or preparing food. If hands are not adequately washed with soap and safe water, microorganisms may be transferred directly to the mouth or indirectly to food and household objects. Wolf et al. (2018), in an updated systematic review and meta-analysis, found evidence that improvements in drinking water, sanitation and handwashing with soap can reduce childhood diarrhoeal disease. Consequently, sanitation assessment should include household handwashing facilities, availability of water and soap, and actual hygiene practices.

Waste management is also central to environmental sanitation. Uncollected household refuse can accumulate in streets, drainage channels, compounds and other open spaces. Such accumulation may create breeding and resting environments for vectors and may facilitate contamination of water and food. When waste blocks drainage channels, stagnant water and flooding may occur, potentially spreading contaminants across residential areas. In Lagos State, waste management is institutionally linked to the Lagos Waste Management Authority (LAWMA), which is responsible for waste-management regulation and related activities across the state. LAWMA identifies increasing population, urbanization, industrialization, economic activities and consumption patterns as factors contributing to increased waste generation in Lagos.

The scale and complexity of Lagos make environmental sanitation particularly important. Lagos is a highly urbanized and densely populated state characterized by extensive residential, commercial and industrial activities. Such characteristics create substantial demands for waste collection, drainage maintenance, wastewater management, sanitation facilities and environmental regulation. The state government has continued to emphasize the importance of proper sanitation and waste disposal. In May 2025, the Lagos State Government reiterated that good sanitation practices should become a daily culture among residents and announced plans concerning the resumption of monthly environmental sanitation activities.

Lagos also faces environmental-management challenges associated with the volume of waste generated within a rapidly growing urban environment. LAWMA reports that waste generation in Lagos has increased alongside population growth, urbanization, industrialization, economic activity and changing consumption patterns. The agency has therefore implemented waste collection, disposal, recycling, enforcement and public education initiatives to promote a cleaner environment. The effectiveness of these institutional interventions, however, is partly dependent on the behaviour and cooperation of residents at household and community levels.

Environmental sanitation is not merely a governmental responsibility. Residents play an important role in determining the sanitary conditions of their immediate surroundings. Proper disposal of household refuse, use and maintenance of toilets, avoidance of open defecation, regular cleaning of compounds, safe disposal of wastewater, proper food handling and handwashing are behavioural practices that can influence exposure to pathogens. Where residents fail to comply with appropriate sanitation practices, even extensive government investment in environmental services may have limited health effects.

Nigeria continues to face substantial WASH challenges. The 2021 Water, Sanitation and Hygiene National Outcome Routine Mapping (WASHNORM), implemented through collaboration involving the Federal Ministry of Water Resources, National Bureau of Statistics, UNICEF, WHO, the World Bank and other partners, reported that about 48 million Nigerians still practised open defecation and that only 8% of the population practised safe handwashing. The report also indicated that only 10% of Nigerians had access to basic water, sanitation and hygiene services combined (Federal Ministry of Water Resources, NBS, World Bank, & UNICEF, 2022). These national conditions demonstrate the continuing need to investigate sanitation practices and associated health outcomes at subnational and community levels.

The Nigerian WASH situation also illustrates the difference between having access to a sanitation facility and achieving effective sanitation. A household may possess a toilet but fail to maintain it hygienically. Similarly, a community may have waste-collection services but continue to experience indiscriminate dumping because residents do not consistently use designated disposal systems. WASHNORM therefore provides an important basis for understanding sanitation not simply in terms of infrastructure but in terms of service availability, use and behavioural practices (Federal Ministry of Water Resources et al., 2022).

Data from the Nigeria Multiple Indicator Cluster Survey also demonstrate substantial variation in WASH indicators across states. The 2021 MICS/NICS reports provide state-level information on drinking water, sanitation and hygiene, allowing differences in access and practices to be examined across the country (National Bureau of Statistics [NBS] & UNICEF, 2022). Such variations are important because national averages can conceal substantial differences between communities, neighbourhoods and population groups. Consequently, community-level assessments are necessary for identifying specific sanitation practices that may contribute to local disease patterns.

Available evidence indicates that Lagos has comparatively high access to some basic WASH services but that significant gaps remain. The 2021 MICS statistical snapshots reported Lagos at 97.9% for basic drinking-water services, 43.7% for basic sanitation services and 39.7% for basic hygiene services. The difference between drinking-water access and sanitation or hygiene coverage is noteworthy. It suggests that the presence of relatively widespread water access does not necessarily imply that residents have adequate sanitation and hygiene services. This distinction is important for a study that seeks to assess environmental sanitation practices and their relationship with diarrhoeal disease.

The issue of sanitation becomes even more significant in densely populated communities where many households share limited infrastructure. Shared toilets, congested residential areas, inadequate waste storage, overflowing drainage systems and poorly maintained sanitation facilities may increase the probability of exposure to faecal organisms. In such settings, the behaviour of one household may affect neighbouring households because environmental contamination can move beyond individual compounds. Environmental sanitation is therefore both an individual and collective public health responsibility.

Historical evidence from Lagos demonstrates that environmental sanitation factors have been associated with diarrhoeal disease. Ekanem, Akitoye and Adedeji (1991), in a case-control study conducted among children aged 6–36 months in Iwaya community in Lagos, observed household sanitation and environmental conditions in relation to diarrhoea. Their findings identified the presence of faeces in or around toilet areas, the use of chamber pots for defecation and urination, indiscriminate waste disposal and domestic water sources as significant factors associated with diarrhoea. Although the study is relatively old, its relevance remains important because it provides location-specific evidence that environmental conditions can influence diarrhoeal disease in Lagos communities.

The historical Lagos evidence also demonstrates why contemporary assessment remains necessary. Environmental conditions, population density, sanitation infrastructure, waste-management systems and residents’ behaviours may change over time. Consequently, findings from earlier studies cannot automatically be assumed to represent present-day conditions. Contemporary urban development, changing household practices, expansion of informal settlements, new waste-management arrangements and evolving patterns of water supply make periodic community-level assessment necessary.

Recent evidence further confirms that diarrhoeal disease remains an important health concern in Lagos. A multicentre hospital study involving 1,679 stool samples collected from patients with diarrhoea across three public hospitals in Lagos State between December 2018 and April 2022 identified a substantial burden of bacterial diarrhoea and demographic and institutional variability in diarrhoeal pathogens. The study recommended strengthened surveillance and targeted public health interventions to reduce diarrhoeal disease transmission (2026). Although hospital-based studies do not directly measure community prevalence, they demonstrate that diarrhoeal illness continues to occur in the Lagos population and that its epidemiology requires sustained attention.

Diarrhoeal disease is also connected with household economic consequences. When individuals become ill, families may incur costs for consultation, medication, laboratory tests and transportation. Recurrent illness can also result in absenteeism from school or work and loss of productivity. WHO emphasizes that poor WASH conditions have consequences extending beyond immediate illness, including effects on well-being, education, work and social development (WHO, 2024). Thus, improving environmental sanitation has potential benefits not only for disease prevention but also for household welfare and community productivity.

Children are particularly vulnerable to the consequences of diarrhoeal diseases. Repeated diarrhoeal episodes can contribute to dehydration and malnutrition, while malnourished children may in turn be more susceptible to severe diarrhoeal illness. WHO identifies diarrhoea as an important contributor to malnutrition among children under five years of age (WHO, 2024). Therefore, community sanitation interventions can contribute to broader child-survival and nutritional objectives.

The relationship between sanitation and diarrhoea has been demonstrated through systematic reviews and meta-analyses. Fewtrell et al. (2005), in a systematic review and meta-analysis of water, sanitation and hygiene interventions in less-developed countries, examined evidence on interventions intended to reduce diarrhoeal morbidity. Their work provides evidence for the importance of environmental and behavioural interventions in diarrhoeal disease prevention. More recent evidence by Wolf et al. (2018) similarly demonstrates the relevance of improved water, sanitation and handwashing practices in reducing childhood diarrhoeal disease.

The quality of drinking water is particularly important because even apparently improved sources can be exposed to contamination. Bain et al. (2014), in a systematic review and meta-analysis of drinking-water contamination in low- and middle-income countries, examined the prevalence of faecal contamination across different water-source types and settings. Their work demonstrated the importance of considering water quality rather than relying exclusively on the classification of a water source as improved or unimproved. This is relevant to communities in Lagos where residents may obtain water from multiple sources and may store water before household use.

Wastewater management is another important component of environmental sanitation. Inadequately managed domestic wastewater may enter open drains, surface waters and residential environments. In urban areas where drainage systems are heavily used, untreated wastewater may contribute to environmental contamination. Lagos State has a dedicated Wastewater Management Office, and the state government has continued to take enforcement action against premises that discharge sewage into public drainage systems. In 2025, for example, the Lagos State Government reported enforcement against a property for discharging untreated sewage into public drains, describing the practice as an environmental and public-health concern.

Drainage conditions are particularly relevant to sanitation in Lagos because heavy rainfall and flooding can redistribute environmental contaminants. When solid waste blocks drains, wastewater and stormwater may overflow into residential areas. Floodwater may then come into contact with faecal matter, refuse and other contaminants, potentially increasing human exposure. WHO recognizes that inadequate sanitation and unsafe water contribute to diarrhoeal disease transmission, making environmental management particularly important in settings vulnerable to flooding (WHO, 2024).

Environmental sanitation also involves food hygiene. Food can become contaminated during preparation, storage, transportation or sale. Contaminated hands, utensils, water, surfaces and raw food materials can introduce pathogens into meals. The WHO identifies contaminated food and poor personal hygiene as important routes of diarrhoeal infection (WHO, 2024). Thus, household sanitation assessment should incorporate food-handling practices, particularly in communities where residents purchase prepared foods from informal vendors.

The importance of environmental sanitation has also been recognized within the regulatory framework of Lagos State. The Lagos State Environmental Protection Agency identifies the Lagos State Environmental (Sanitation and Waste Control) Regulations 2014 among the environmental regulations applicable in the state. Such regulations provide an institutional framework for controlling sanitation and waste-related environmental risks. However, the existence of regulations does not necessarily mean that all residents comply with them. Compliance at the community level therefore remains an important area for empirical assessment.

Public health interventions aimed at diarrhoeal disease prevention must therefore consider both environmental infrastructure and human behaviour. Providing toilets without ensuring their proper use and maintenance may not adequately interrupt disease transmission. Similarly, waste collection services may have limited effect where households continue to dump refuse in drains or unauthorized locations. Effective sanitation requires a combination of adequate facilities, reliable services, appropriate knowledge, positive attitudes, consistent practices and effective enforcement.

The problem is further complicated by inequalities within urban communities. Not all residents of Lagos experience the same environmental conditions. Some households may have access to private toilets, reliable water supplies, regular waste collection and functional drainage, while others may depend on shared facilities, alternative water sources and irregular waste-disposal arrangements. WHO notes that inequalities in access to WASH services persist within urban areas, particularly among populations living in low-income and informal settlements (WHO, 2023).

The 2024 WHO sanitation fact sheet emphasizes that poor sanitation remains associated with substantial disease and mortality worldwide. WHO estimates that inadequate sanitation contributes to hundreds of thousands of deaths annually and that unsafe sanitation is a major contributor to diarrhoeal disease burden (WHO, 2024). These findings demonstrate that sanitation is not simply an environmental issue but a central public health intervention.

The WHO/UNICEF Joint Monitoring Programme also shows that substantial global gaps remain. The latest JMP report covering 2000–2024 indicates that, despite progress, 3.4 billion people globally still lacked safely managed sanitation services in 2024. These figures underscore the continuing global relevance of sanitation improvement and provide an international context for examining sanitation practices within Lagos communities.

At the Nigerian level, UNICEF emphasizes the relationship between inadequate WASH conditions and childhood morbidity and mortality. UNICEF Nigeria reports that poor access to improved water and sanitation contributes to high morbidity and mortality among children under five and identifies diarrhoeal disease as a major health consequence of poor sanitary conditions. This further establishes the importance of investigating sanitation practices as part of disease-prevention efforts in Nigerian communities.

The present study is therefore situated within the broader public health concern of preventing environmentally transmitted diseases through improved sanitation. Its focus is not merely on whether sanitation facilities exist but on the actual practices of residents, including waste disposal, toilet use and maintenance, wastewater disposal, drainage conditions, water handling, handwashing and general environmental cleanliness. Assessing these practices alongside the prevalence of diarrhoeal diseases can provide evidence regarding the extent to which sanitation conditions may be associated with diarrhoeal illness.

The choice of selected communities in Lagos State is also significant because state-wide averages may conceal substantial differences in environmental conditions between communities. Localized assessment can identify specific sanitation practices that require attention and can provide evidence for community health education, environmental regulation, WASH programming and disease-prevention interventions. UNICEF’s recent work on small-area estimation in Nigeria similarly emphasizes the importance of localized information for planning targeted health interventions and allocating resources effectively (UNICEF, 2025).

Consequently, this study seeks to assess environmental sanitation practices and determine the prevalence of diarrhoeal diseases among residents of selected communities in Lagos State. It will examine sanitation practices such as waste disposal, toilet and excreta management, water handling, hand hygiene, wastewater disposal, drainage and general environmental cleanliness. It will also investigate the occurrence of diarrhoeal disease among residents and determine whether significant relationships exist between environmental sanitation practices and diarrhoeal disease prevalence. The findings are expected to contribute to evidence-based environmental health interventions aimed at reducing preventable diarrhoeal illness in Lagos communities.

1.2 Statement of the Problem

Diarrhoeal diseases remain a significant public health problem despite the fact that many of the environmental conditions that contribute to their transmission are preventable. The WHO identifies unsafe water, inadequate sanitation and poor hygiene as important determinants of diarrhoeal disease, while emphasizing that improved water, sanitation and handwashing can substantially reduce disease risk (WHO, 2024). The continued occurrence of diarrhoeal diseases therefore raises questions about the adequacy of sanitation infrastructure, the effectiveness of environmental health services and the sanitation practices of residents.

Nigeria continues to experience considerable WASH challenges. The 2021 WASHNORM report found that about 48 million Nigerians practised open defecation and that only 8% of the population practised safe handwashing. Only 10% had access to basic water, sanitation and hygiene services combined (Federal Ministry of Water Resources et al., 2022). These conditions create opportunities for faecal contamination and transmission of enteric pathogens and demonstrate the continuing need for sanitation-focused public health interventions.

The situation is particularly important in Lagos State because of its extensive urbanization, population concentration and large volume of household and commercial activities. The state’s rapid urban development generates substantial quantities of solid waste and places continuous pressure on waste collection, drainage, wastewater management and sanitation facilities. LAWMA acknowledges that population growth, urbanization, industrialization, economic activities and changing consumption patterns contribute to increasing waste generation in Lagos.

Although Lagos has institutional mechanisms for environmental sanitation and waste management, sanitation problems continue to be reported. The Lagos State Government has repeatedly emphasized the need for residents to adopt proper sanitation practices, while LAWMA and other environmental agencies continue enforcement and public-awareness activities. The persistence of such interventions suggests that environmental sanitation remains an ongoing challenge requiring behavioural as well as infrastructural solutions.

A major concern is indiscriminate disposal of household waste. When refuse is deposited in unauthorized locations, drains and open spaces, it may contribute to blocked drainage systems, environmental pollution and the proliferation of unsanitary conditions. During rainfall, waste and contaminated materials may be transported into residential environments and water bodies. Such conditions can facilitate exposure to pathogens and increase the potential for enteric disease transmission.

Poor toilet and excreta management represents another important problem. The absence of adequate toilets, overcrowding of shared facilities, poor cleaning, improper disposal of children’s faeces and open defecation can create opportunities for faecal contamination. WHO identifies human faeces as an important source of pathogens capable of contaminating water and environments and causing diarrhoeal diseases (WHO, 2024).

The problem is not necessarily resolved by the mere presence of toilet facilities. Toilets must be accessible, functional, clean and properly maintained. Where sanitation facilities are poorly maintained, faecal matter may remain around the toilet environment and become a source of contamination. Evidence from Iwaya in Lagos showed that the presence of faeces in and around toilet areas was associated with diarrhoeal disease among children, demonstrating the relevance of sanitation-facility conditions to local disease transmission (Ekanem et al., 1991).

Water handling is also a concern. Even when households obtain water from improved sources, contamination can occur during transportation and storage. The use of contaminated containers, uncovered storage vessels and unclean utensils can compromise water quality before consumption. WHO (2023) stresses that microbial contamination of water by faecal material remains an important public-health risk and that safe water is essential for effective hygiene practices.

Handwashing practices may further influence the risk of diarrhoeal disease. Residents may possess handwashing facilities but fail to wash their hands at critical times, particularly after defecation, after cleaning children, before preparing food and before eating. The Nigerian WASHNORM finding that only 8% of the population practised safe handwashing indicates the magnitude of the national challenge (Federal Ministry of Water Resources et al., 2022). The extent to which similar behavioural gaps exist in selected Lagos communities requires empirical assessment.

Wastewater and drainage constitute additional areas of concern. Inadequately disposed domestic wastewater may flow through open spaces or drains, while blocked drainage channels may cause wastewater and stormwater to accumulate in residential areas. The Lagos State Government has recently taken action against premises involved in the discharge of untreated sewage into public drains, demonstrating that wastewater disposal remains an environmental concern within the state.

The consequences of inadequate environmental sanitation extend beyond unpleasant surroundings. Poor sanitation can facilitate the spread of infectious diseases, reduce quality of life and increase household healthcare expenditure. WHO identifies inadequate WASH as a major contributor to preventable disease and mortality, with diarrhoeal disease constituting one of the major health outcomes associated with poor sanitation (WHO, 2023, 2024).

There is also a particular concern about the health of children. Diarrhoea can lead to dehydration, nutritional deficiencies and impaired growth, while repeated illness can increase vulnerability to other health problems. WHO reports that diarrhoeal disease is a leading cause of childhood mortality and contributes substantially to childhood malnutrition (WHO, 2024). Consequently, preventing environmental transmission of diarrhoeal pathogens is essential to child-health improvement.

Another problem is the possibility of a gap between sanitation policy and sanitation practice. Lagos State has environmental regulations and agencies responsible for waste management and environmental protection. LASEPA identifies the Environmental (Sanitation and Waste Control) Regulations 2014 among the state’s environmental regulatory instruments. However, the existence of regulatory frameworks does not guarantee compliance by individual households and communities. There is therefore a need to assess what residents actually do in their daily lives.

Existing Nigerian studies provide evidence that environmental factors are related to diarrhoeal disease, but location-specific evidence needs to be continually updated. The Lagos study by Ekanem et al. (1991) established associations between diarrhoea and sanitation-related factors, including indiscriminate waste disposal and domestic water sources. However, substantial changes in Lagos’s population, urban structure, waste-management systems, water-supply arrangements and sanitation policies have occurred since that study was conducted.

Furthermore, recent hospital-based evidence from Lagos indicates that diarrhoeal disease remains an important health concern. A multicentre study of diarrhoeal patients in three public hospitals in Lagos between 2018 and 2022 found substantial bacterial diarrhoeal disease and recommended stronger surveillance and targeted interventions (2026). Nevertheless, hospital-based surveillance cannot fully explain the sanitation practices of residents in the community or establish how common diarrhoeal disease is among the wider resident population.

A further problem is that aggregate state or national statistics can conceal differences among communities. The 2021 MICS demonstrated variations in WASH indicators across Nigerian states, while more recent UNICEF work has emphasized the value of localized data for health planning. Therefore, a community-level study in selected areas of Lagos State can provide more specific information about sanitation conditions and diarrhoeal disease than broad state-level indicators alone.

The relationship between sanitation and diarrhoeal disease is theoretically well established, but the actual strength of this relationship may vary according to local environmental and behavioural conditions. For example, two communities may have similar access to toilets but differ considerably in waste disposal, water storage, handwashing, wastewater management and environmental cleanliness. Wolf et al. (2018) demonstrated that WASH interventions can reduce diarrhoeal disease, but intervention effectiveness depends on the nature and level of exposure being addressed. This reinforces the need for local assessment rather than assuming that all communities experience the same sanitation-related risks.

The problem, therefore, is not simply the existence of diarrhoeal diseases or the absence of sanitation facilities. The central concern is the extent to which residents actually practise appropriate environmental sanitation and whether poor sanitation practices are associated with diarrhoeal disease occurrence. Without such information, environmental health authorities and community health workers may have difficulty identifying which sanitation behaviours require the greatest attention.

It is against this background that this study is designed to assess environmental sanitation practices and the prevalence of diarrhoeal diseases among residents of selected communities in Lagos State. The study seeks to generate empirical evidence on sanitation practices, determine the prevalence of diarrhoeal diseases among residents, identify common sanitation-related risk factors and examine whether environmental sanitation practices are significantly associated with diarrhoeal disease occurrence. The findings may provide useful evidence for environmental health education, community sanitation programmes, WASH interventions, disease surveillance and policy implementation in Lagos State.

1.3 Purpose of the Study

The general purpose of this study is to assess environmental sanitation practices and the prevalence of diarrhoeal diseases among residents of selected communities in Lagos State.

Specifically, the study seeks to:

1. assess the environmental sanitation practices of residents in the selected communities;
2. determine the prevalence of diarrhoeal diseases among residents of the selected communities;
3. examine residents’ practices regarding household waste disposal;
4. assess the adequacy and maintenance of toilet and excreta-disposal practices among residents

1.4 Research Questions

The following research questions will guide the study:

1. What are the environmental sanitation practices of residents in the selected communities in Lagos State?
2. What is the prevalence of diarrhoeal diseases among residents of the selected communities?
3. What methods of household waste disposal are commonly practised by residents?
4. How adequate and well maintained are toilet and excreta-disposal facilities in the selected communities?

1.5 Research Hypothesis

The following null hypothesis will be tested at 0.05 level of significance:

H₀: There is no significant association between environmental sanitation practices and the prevalence of diarrhoeal diseases among residents of selected communities in Lagos State.

1.6 Significance of the Study

The study will be significant to residents of the selected communities because it will provide information on how everyday sanitation behaviours can influence exposure to diarrhoeal diseases. Findings from the study may encourage residents to improve household waste disposal, toilet maintenance, handwashing, water handling and general environmental cleanliness.

The study will also be significant to community health workers. The findings may provide evidence that can guide health education programmes focusing on sanitation-related behaviours. Community health workers can use the findings to identify common practices that require behavioural modification and to strengthen preventive health education.

The study will be useful to Lagos State environmental health authorities because it will provide community-level evidence regarding sanitation practices. Such information can support the design of targeted environmental sanitation programmes, enforcement activities and community mobilization strategies.

The study will also benefit LAWMA and related environmental agencies by providing information on residents’ waste-disposal practices and possible environmental challenges at community level. Such information may contribute to improvements in waste-collection education, community sensitization and environmental compliance.

The study may be useful to public health planners and policymakers. Evidence concerning the relationship between sanitation practices and diarrhoeal disease can support the development of integrated WASH and disease-prevention strategies. WHO and UNICEF continue to emphasize integrated water, sanitation and hygiene interventions as essential components of disease prevention (WHO, 2024; UNICEF, 2025).

The study will also be useful to healthcare providers and disease-surveillance personnel because information on community prevalence can complement facility-based data. Recent Lagos evidence demonstrates that diarrhoeal diseases continue to present a burden in healthcare settings, making community prevention and surveillance important (2026).

Finally, the study will contribute to academic knowledge and future research by providing contemporary evidence on environmental sanitation and diarrhoeal diseases in selected Lagos communities. It may also serve as a reference for researchers in environmental health, public health, community medicine, epidemiology and related disciplines.

1.7 Scope of the Study

The study focuses on the assessment of environmental sanitation practices and the prevalence of diarrhoeal diseases among residents of selected communities in Lagos State.

The study will cover major environmental sanitation practices, including:

• household solid-waste disposal;
• toilet availability, use and maintenance;
• human-excreta disposal;
• wastewater disposal;
• drainage conditions;
• domestic water sources and water handling;
• household water storage;
• handwashing practices;
• food hygiene;
• general household and community environmental cleanliness; and
• residents’ experience of diarrhoeal disease.

The study will focus on residents of the selected communities within Lagos State. The prevalence of diarrhoeal diseases will be assessed based on the operational definition adopted for the study and the period specified in the research instrument.

1.8 Delimitation of the Study

The study is delimited geographically to selected communities in Lagos State. It does not attempt to cover all communities or all Local Government Areas in Lagos State.

Conceptually, the study is restricted primarily to environmental sanitation and diarrhoeal diseases. Other health outcomes associated with poor sanitation, such as malaria, typhoid fever, intestinal helminth infections and respiratory infections, are outside the primary focus of the study.

The study will examine sanitation-related behavioural and environmental factors rather than undertaking extensive laboratory identification of every possible causative organism of diarrhoea. Where diarrhoeal disease prevalence is assessed through respondents’ reports, the findings will therefore reflect the study’s operational definition and data-collection method.

1.9 Operational Definition of Terms

Assessment: The systematic process of collecting and analysing information to determine the level, condition or effectiveness of environmental sanitation practices and the occurrence of diarrhoeal diseases among residents.

Diarrhoeal Disease: A condition characterized by the passage of three or more loose or liquid stools in a day, or more frequently than is normal for an individual, generally resulting from gastrointestinal infection (WHO, 2024).

Environmental Sanitation: Measures and practices concerned with maintaining a clean and safe physical environment through appropriate management of human excreta, solid waste, wastewater, drainage, water, food hygiene and related environmental conditions.

Environmental Sanitation Practices: The actual behaviours adopted by residents to maintain sanitary household and community environments, including waste disposal, toilet use and maintenance, wastewater disposal, drainage management, water handling, handwashing and general environmental cleanliness.

Prevalence: The proportion of residents in the study population who experience or report diarrhoeal disease within the specified period of the study.

Residents: Individuals who live within the selected communities in Lagos State and satisfy the inclusion criteria established for participation in the study.

Solid Waste: Discarded household, commercial or other non-liquid materials generated within homes and communities that require appropriate collection, storage, transportation and disposal.

Waste Disposal: The process through which household and community waste is stored, collected, transported and finally discarded or otherwise managed.

Sanitation Facility: A facility designed for the safe containment and disposal of human excreta, including toilets and latrines.

Hand Hygiene: The cleaning of hands using appropriate methods, particularly at critical times such as after using the toilet, after cleaning a child, before preparing food and before eating.

Safe Water: Water that is sufficiently protected from contamination and is suitable for its intended domestic use, particularly drinking and food preparation.

WASH: Water, Sanitation and Hygiene, referring collectively to the services, facilities and behaviours necessary for protecting health through safe water, adequate sanitation and appropriate hygiene practices.

Project – Assessment of Environmental Sanitation Practices and the Prevalence of Diarrhoeal Diseases among Residents of Selected Communities in Lagos State