MICROBIAL PROFILING AND TOXICOLOGICAL ASSESSMENT OF JABI LAKE WATER ABUJA, NIGERIA
ABSTRACT
The increase in urbanization and socio-economic activities within and around Jabi lake may have led to heavy metal pollution and microbial contamination stemming from discharge of erosion runoffs, open defecation and other activities that encourage pollution of the lake. The aim of this study was to carry out microbial profiling and toxicological assessment on Jabi Lake water from the FCT, Nigeria. The water samples denoted as S1, S2, S3 and S4 were collected from (9.0717990, 7.4165487), (9.0708280, 7.4182928), (9.0708981, 7.4214155), and (9.0682332, 7.4201693) respectively at a depth of 0.55m. Physicochemical, microbiological, and toxicological analyses were carried out on the water samples collected in duplicates from Jabi Lake, Nigeria. These acquired outcomes were juxtaposed against World Health Organization (WHO) guidelines for surface water. The samples S1, S2, S3, and S4 had a temperature of 28.1ºC, 28.2ºC, 28.0ºC, and 28.1ºC, pH of 7.2, 7.1, 7.3, and 7.1, electrical conductivity of 180, 150, 140, and 140 s/cm, total dissolved solids (TDS) of 130, 110, 107, and 107 ppm, alkalinity of 190, 156, 166, 170 ppm, turbidity of 25.2, 24.7, 22.6, and 24.7 NTU, and dissolved oxygen of 46, 50, 49, and 49 ppm. In comparison with WHO guidelines, the pH, electrical conductivity, total dissolved solids, and alkalinity were within the permissible limits of 6.5 – 8.5, 1000 s/cm, 500 ppm, and 200 mg/L respectively, while turbidity and dissolved oxygen values were above permissible limits of 5 NTU, and 8 – 10 ppm respectively. Thirty-three (33) bacterial isolates belonging to eight genera were identified as E. coli, Klebsiella pneumoniae, Bacillus spp., Pseudomonas sp., Enterobacter, Proteus sp., S. aureus, and S. epidermidis with occurrence rates of 24.2%, 21.2%, 6.0%, 9.1%, 9.1%, 6.1%, 15.1%, and 9.1% respectively. Thirteen (13) fungal isolates belonging to six genera were identified as Fusarium sp., Aspergillus sp., Microsporum sp., Cladosporium sp., Rhizopus sp., and Candida sp., with occurrence rates of 16.7%, 8.3%, 25%, 16.7%, 25%, and 8.3%. None of the samples complied with bacteriological standards, as the total fecal coliform counts of all the samples were between 1600 for S1 and >1600 MPN index per 100mL for S2, S3 and S4, and the presence of fecal coliforms like E. coli was established. The total viable bacterial counts were 1.72×107, 1.07×107, 1.15×107, and 1.6×107 cfu/mL, for S1, S2, S3, and S4 respectively, with the highest total viable bacterial count being recorded at S1. The heavy metal concentration for S1, S2, S3, and S4 were 0.093, 0.089, 0.140, and 0.085 mg/L respectively for zinc. Chromium concentrations were 2.039, 2.059, 2.060, and 2.036 mg/L for S1, S2, S3, and S4 respectively. The concentration of lead for samples S1, S2, S3, and S4 was 0.184, 0.186, 0.384, and 0.178 mg/L respectively, and cadmium concentrations were 0.014, 0.014, 0.015, and 0.013 for S1, S2, S3, and S4 respectively. The concentration of zinc in all the samples was within WHO guidelines (5 mg/L), while the concentrations of chromium, lead and cadmium were above WHO guidelines (0.01, 0.05, and 0.005 mg/L respectively). The sample S3 had the highest heavy metal concentration. The results from this study indicate pollution of the lake with pathogenic microorganisms and heavy metals. The microorganisms isolated in this study have been implicated as pathogens. Pollution of this lake with heavy metals pose the risk of poisoning to aquatic lives and the humans that rely on these aquatic organisms as a source of food. Indiscriminate disposal of effluents have to be curbed, and an overall monitoring of the activities around the lake in order to prevent further pollution.
CHAPTER ONE
INTRODUCTION
1.1. Background to the study
From the inception of time, human beings have constantly relied on water for domestic, industrial and other purposes. Water is essential for human survival and well-being, and plants need water for growth. Water serves as a critical factor contributing to the proliferation of species as a result of its peculiar composition. It is a vital element of life containing minerals very vital in the nutrition of humans, and is also essential for life sustenance. In infants, 75% of their body weight is attributed to water, similar to the 55% of adults. It is also important in preserving and maintaining the stability of cellular functions (Satish et al., 2016).
Water plays a pivotal role in ensuring for economic growth, employment, social development and sustainability of the environment. It is a resource important to communities both for their own survival and their contribution to the needs required by society (Doe et al., 2016).The significance of water cannot be overstated, as there are several facts that have been scientifically and economically reviewed, that the shortage of water or its pollution can result in gross productivity reduction and the mortality of living entities (Ezeamaka et al., 2019). Lakes are reservoirs containing water of great importance for fishing, agricultural, industrial and domestic usage. The reservoirs serve as regions of biodiversity and are also used as tourists, recreational and conservation locations. Surface waters such as lakes are predominantly a critical source in the transmission of diseases which is linked to the subjection of people to disease causing organisms habited in these water bodies. The potential health decline associated with the occurrence of these microbes is incumbent on the disease causing organism, form and predominance. Pollution of fecal roots, use of land, and anthropological practices have been identified as some of the critical reasons responsible for the occurrence of disease-causing organisms in waters used for recreational purposes (Matouke & Nour, 2019; Rodrigues & Cunha, 2017).
With increased urbanization and industrialization, lakes are compromised with arising natural pollutants, heavy metals included. These metals are in some cases of regular and anthropogenic roots. The contaminants, when released into water bodies, gather in aquatic organisms like planktons and fishes, with hostile consequences on their wellbeing. Even though a few lakes actually have regular degrees of heavy metals in them, many have raised fixations because stemming from anthropological sources including vehicular, household, agricultural, industrial and mining activities (Sibal & Espino, 2018; Matouke & Abdullahi, 2020).
1.2. Statement of the research problem
One of the major vital and basic factor of deterioration of lakes is the decline in the quality of water as a result of organic pollution due to the disposal of municipal wastes (Prathiba, 2019). Pollution of water with deleterious microorganisms including bacteria, viruses, parasites, as well as fungi, has been on steady increase globally. Waterborne pathogens present a great health risk to people using lake water for drinking, bathing, washing, irrigation of crops eaten raw, fishing, and recreational activities. (Doe et al., 2016). It has been observed that communicable diseases still remain the top causes of mortality on a global scale.
From an evolutionary and nutrition based standpoint, metal poisoning is a noteworthy issue. These metals can inhibit cognitive and psychological growth of children, alongside causing a rise in blood pressure and vulnerability to heart diseases in adults (Matouke & Abdullahi, 2020). In rivers and lakes across the world, the concentration of heavy metals above the publicized minimum value as per the World Health Organization (WHO) were generally lower in the 1990s, 2000s, and 2010s. Along the years, the concentrations of heavy metals that pollute surface waters have shifted from single concentrations to mixed metal pollution. The concentrations above the permissible limits were lower in developed countries of Europe and
North America, and higher in the developing countries of Africa, Asia, and South America (Zhou et al., 2020).
Environmental activities around Jabi Lake are a mall, and a recreational park that benefits a wide range of people. However, the rapid spread of urbanization and socio-economic activities in and within the lake presents the danger of pollution with wastes including chemicals such as heavy metals. The lake would like have witnesses series of both heavy metal pollution and microbial contamination, stemming from flower farming, block moulding industries around the lake, as well as the discharge of erosion run-offs into the lake, which would without a doubt stream along with it domestic wastes. The presence of these contaminants in the lake would lead to bioaccumulation in aquatic life (Ezeamaka et al., 2019).
1.3. Justification for the study
In order to reduce waterborne disease outbreaks, the World Health Organization (WHO) developed microbiological quality guidelines for each intended water use. Microorganisms such as fecal coliforms have been used in developing regulatory standards or quality guidelines, since they are a common indicator of both fecal contamination and microbial water quality for water systems (Doe et al., 2016).
Humans are bared to heavy metals which stems from an incline in pollution as a direct cause of industrialization, and human practices, and lake waters are a major reservoir for wastes containing these metals. The subjection of humans to these metals is imminent as they are largely dispensed in the ecosystem from different origins. Also, they can amass and thereby magnify through the trophic level in the environment due to the level of their nonbiodegradability and persistence (Anyanwu et al., 2018).
Since there are no effective laws regulating illegal waste disposal and pollutants of organic origin into the environment especially water bodies such as lakes, it is thereby of necessity to evaluate the degree of pollution of such water bodies as regards microbial contamination and toxic deposits.
1.4. Aim and objectives of the study
This study is aimed at carrying out microbiological profiling, and toxicological assessment on Jabi lake water from the FCT, Nigeria.
The specific objectives of this study are:
- To isolate bacteria and fungi in water samples collected from Jabi Lake.
- To identify bacteria and fungi present in water samples from Jabi Lake.
- To determine the microbial load of the water samples from Jabi Lake.
- To determine the physicochemical composition of the water samples from Jabi Lake.
- To determine the concentration of heavy metals like zinc (Zn), chromium (Cr), lead
(Pb), and cadmium (Cd) in water samples from Jabi Lake.
MICROBIAL PROFILING AND TOXICOLOGICAL ASSESSMENT OF JABI LAKE WATER ABUJA, NIGERIA