4.1. Discussion of the Findings
Within the last two decades, the proportion of Nigerians with access to improved sanitation has declined, while the practice of open defecation has risen. However, other countries in sub-Saharan Africa have on average made substantial progress. In Nigeria, VIP latrines, pit latrines with a slab and pit latrines without a slab collectively constituted the dominant types of sanitation facilities (44%) in 2013. Since they are cheaper to construct and maintain compared to modern facilities, these facilities are more preferred by the poor, who constituted more than two-thirds of Nigerians (70% below poverty line) in 2010 [3
]. Considering that pit latrines without a slab are an unimproved type of facility that exposes people to health risks and can cause injuries when people accidently fall inside (especially children), there is the need for more efforts to assist households in upgrading to improved latrines. It is also important to educate households on how to maintain hygienic conditions in their improved latrines. This is because a study found that satisfaction with and use of sanitation facilities depend on whether facilities are improved (40%), cleaned (37%) and not shared (16%) [18
Similarly, as far as the overwhelming majority of Nigerian urban areas remain unconnected to central sewer system, substantial progress cannot be made in improving access to the system. Similarly, a shortage of domestic water supply being experienced in several parts of Nigeria [23
] grossly undermines the use of modern sanitation facilities. While the use of crude sanitation facilities is fizzling out (3%), close to one-third (31%) of Nigerian households defecate in the open, which is higher than sub-Saharan African average of 23% and much higher than that of Ghana (19%), Kenya (12%) and South Africa (4%) in 2015 [1
]. The sub-Saharan African countries with higher prevalence of open defecation in 2015 include Liberia (48%), Togo (52%) and Burkina Faso (55%) [1
]. Main reasons for open defecation include unhygienic conditions of existing facilities, high cost of building a toilet, shortage of space at home and vegetation type [19
Pertaining to the second objective of the study, the results indicated significant relationships between types of household sanitation facilities and socioeconomic and locational factors. Like previous studies, living in urban areas increases the possibility of using improved sanitation facilities and rural living increases the possibility of open defecation and using unimproved facilities. For example, two-thirds (66.8%) of surveyed households with access to improved facilities lived in urban areas in Indonesia, [11
]. Also, households in Ghana country side were 0.58 times less likely to have improved facilities than urban households [13
]. Globally, the proportion of rural population using unimproved facilities is about thrice (50%) the urban one (18%) [2
]. A likely reason for the disparity includes agrarian life where rural populations stay away from built areas where sanitation facilities are available, concentration of poverty in rural areas and less appreciation of the health risks of open defecation among rural households.
With regards to regional disparity, the use of sewer systems and VIP latrines was highest in North Central and North West respectively. Over two-thirds of all households that used the hanging toilet were from the South South zone. This result concurs well with a few earlier studies. In Ghana for instance, the Greater Accra region has the highest proportion of access to improved sanitation facilities as opposed to the northern region [13
]. The unique characteristics of each region, its people and their socioeconomic challenges, and differences in vegetation, climate and topography are the possible reasons for the variation in the type of facilities household used across regions. In terms of ethnicity, the significant relationship between ethnicity and household type of sanitation facility and open defection practice found in the present study suggests that the ethnic groups in Nigeria have varied preferences for different sanitation facilities and attitudes towards the practice of open defecation.
Furthermore, while more educated households used modern sanitation facilities, less educated ones used pit latrines and practiced open defecation the most, as reported in previous studies [11
]. A likely reason is that educated households are more aware about the risks of unimproved sanitation and poor hygiene associated with pit latrines. Awareness of the benefits of safe sanitation were found to increase the likelihood of having improved sanitation facility nine-fold among households in rural Tanzania [16
]. Similarly, households headed by persons with at least secondary education in Indonesia and those headed by persons with higher education in Ghana, were respectively 3.0 and 2.5 times more likely to use improved sanitation facility compared to households with lower educational levels [11
]. Educational attainment is thus key towards understanding inequity in access to sanitation facilities.
This study also found that the poorest, poorer and middle class combined constituted about four out of five of those who defecate in the open. A likely reason is that the relative costs of different sanitation facilities make the likelihood of using unimproved facility and practicing open defecation increase with decreasing wealth [13
]. For example, the likelihoods of using improved sanitation facilities and VIP latrines were more than twice higher in higher-income households than in lower-income households in rural Ethiopia (odds ratio (OR): 2.3) [15
] and Tanzania (OR: 2.1) [16
] respectively. Although poverty is significantly related to using unimproved facilities or open defecation, as mentioned earlier, the present study found that their magnitudes did not simply increase by decreasing wealth. For example, open defecation was higher in middle income households than in poorer and poorest households and the use of hanging toilets was higher in middle class and richer households than in poor and poorer ones. This suggests that the relationship between the type of household sanitation facility and wealth is not linear when moving from the poorest to the richest.
Regarding the last objective of the study, the regression model indicated that among the factors that influenced the type of sanitation facility households used, wealth index has the largest effect followed in decreasing order by state, ethnicity, place of residence, local government area, access to electricity and type of water source. This finding is in line with that of earlier studies. For example, in Yemen the probability of access to improved sanitation facilities is 20% higher for people living in urban than rural areas and 18% higher for those connected with public electricity than those not connected [12
]. In Ghana, households who used improved drinking water source were 1.36 times more likely to use improved sanitation facilities than those with unimproved water sources. Unlike in the present study, no statistically significant association was found between educational status and access to improved sanitation facilities in a rural community in Ethiopia [15
] and in the Bomet municipality in Kenya [17
]. Similarly, household size was not significantly associated with the type of toilet facility used by surveyed households in Kenya [17
]. The likely reason for these contrary findings is that both studies were conducted at rural or urban level based on smaller samples of 150–515 households, unlike the national-level studies that used secondary data from substantially large samples.
On the other hand, the present study found that the age of household head and type of household cooking fuel have no significant association with the type of household sanitation facility. However, the gender of household head in both the multivariate regression and t
-test (Table A1
in the Appendix A
) is one of the significant predictors of household’s type of sanitation facility. Mixed results have been reported in the literature concerning the relationship between gender and access to sanitation facilities. In Ghana, households headed by females were 2.54 times more likely to have improved sanitation facilities than those headed by males [13
]. Conversely, male-headed households in a municipality in Kenya were more likely to have improved sanitation facilities than female-headed households [17
]. Similarly, female-headed households were 60% less likely to own VIP latrines than male-headed households in rural Tanzania [16
]. These conflicting findings could be due to the different emphasis on sanitation placed by male or female respondents in those different studies.
4.2. Sustainability Implications
There is increasing appreciation of the linkages between sanitation and environmental, social, and economic pillars of sustainability. The use of unimproved sanitation facilities by over two-thirds of Nigerians is really a sanitation crisis that has serious environmental sustainability implications. Although the use of crude sanitation facilities (hanging toilet, flush to nowhere, bucket toilets and others) is fizzling out, open defecation is on the rise, which can cause several environmental problems, including contamination of surface water through runoff, which can render water bodies uninhabitable for many organisms, and expose people to diseases when they drink or swim in the water. As close to one-third of Nigerians still defecate in the open, achieving the SDG 6.2 in the country is not possible without eliminating the practice altogether. Open defecation is the worst form of sanitation as it pollutes public open spaces, water bodies, railway lines, building construction sites, and includes the use of flying toilets (which is a form of open defecation inside polythene bags and throwing it away) [19
]. Human behavior has been reported to contribute to the prevalence of open defection in sub-Saharan Africa [25
]. For example, parents were reported to allow their children to defecate in the open for the fear of the children falling into pit latrines or dirtying flush toilets [19
]. Some studies also reported than even with the availability of latrines, certain people do defecate on the ground rather than inside the pit [18
]. Similarly, high incidence of pit latrines is associated with underground water contamination that could pose threats to households that use local wells located in proximity to the latrines. Even flush toilets, as the best form of sanitation facilities, can only transport excreta but cannot render it harmless, as sewage treatment in developing countries is not fully effective because untreated sewage is often discharged into water bodies [24
]. There are also reports of some households and trucks that empty sewage they evacuated from septic tanks into running storm water and water bodies respectively [27
From a health perspective, use of unimproved sanitation facilities and unsustainable disposal of human waste is a leading cause of diseases transmitted via human excrement, such as diarrhea, hepatitis and typhoid fever [28
]. Open defecation and the use of unimproved sanitation facilities, highly prevalent among Nigerian population, have dangerous effects on human health, particularly with respect to diarrhea. The percentage of children under the age of five who had diarrhea two weeks prior to the survey was higher among rural (10.8%) than urban households (9.2%), and highest in North East zone (21.1%), followed by South East (10.3%) and North West (9.2%), areas that the NDHS found to have higher utilization of unimproved sanitation facilities and practice of open defecation [4
] (p. 166). Nigeria is the second largest contributor to the under–five mortality rate in the world (after India) with about 2300 deaths daily, of which 10% is from diarrhea [1
]. The implications of this include increasing demand on the already overwhelmed healthcare systems of the country. Globally, about 88% of diarrheal diseases can be ascribed to poor sanitation and hygiene and unclean water [7
]. Certainly, facilitating access to improved sanitation facilities have great health benefits, including reduction in diarrhea risk by up to 37%, and schistosomiasis by up to 77% [7
From the equity perspective, improving access to adequate sanitation is necessary for protecting human dignity and privacy. Lack of access to adequate sanitation is among the principal factors hindering progress towards the poor meeting their basic needs and it is a misery for women and children who are often physically attacked when using facilities outside their homes [28
]. Adequate sanitation encourages children to attend schools, particularly girls: an increase in girls’ enrolment have been credited to providing separate sanitary facilities for girls [1
]. Also, as shown in this study ethnicity as a sub-culture and regional variations have significant influence on the facilities household used and the practice of open defecation. As such, even the improved sanitation facilities would not achieve the aim of hygienic separation of waste from human contact without behavior change. As such, efforts to increase access to improved sanitation should be coupled with schemes to promote appropriate utilization of sanitation facilities [16
From the economic point of view, poor sanitation leads to poor health status, which in turn leads to lower productivity [1
]. Lack of proper sanitation and hygiene cost developing countries a substantial proportion of their GDP, which includes costs of healthcare, loss of income due to illness, and time spent seeking for places to defecate. Sanitation improvement contributes to poor household economies through reduced costs and losses of time.