Browsing by Author "Timothy, Omara"

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Aflatoxins in Uganda: an encyclopedic review of the etiology, epidemiology, detection, quantification, exposure assessment, reduction, and control
(International Journal of Microbiology, 2020-01-08) Timothy, Omara; Winfred, Nassazi; Tom, Omute; Aburu, Awath; Fortunate, Laker; Raymond, Kalukusu; Bashir, Musau; Brenda, Victoria Nakabuye; Sarah, Kagoya; George, Otim; Eddie, Adupa
Uganda is an agrarian country where farming employs more than 60% of the population. Aflatoxins remain a scourge in the country, unprecedentedly reducing the nutritional and economic value of agricultural foods. This review was sought to synthetize the country’s major findings in relation to the mycotoxins’ etiology, epidemiology, detection, quantification, exposure assessment, control, and reduction in different matrices. Electronic results indicate that aflatoxins in Uganda are produced by Aspergillus flavus and A. parasiticus and have been reported in maize, sorghum, sesame, beans, sunflower, millet, peanuts, and cassava. The causes and proliferation of aflatoxigenic contamination of Ugandan foods have been largely due to poor pre-, peri-, and postharvest activities, poor government legislation, lack of awareness, and low levels of education among farmers, entrepreneurs, and consumers on this plague. Little diet diversity has exacerbated the risk of exposure to aflatoxins in Uganda because most of the staple foods are aflatoxin-prone. On the detection and control, these are still marginal, though some devoted scholars have devised and validated a sensitive portable device for on-site aflatoxin detection in maize and shown that starter cultures used for making some cereal-based beverages have the potential to bind aflatoxins. More efforts should be geared towards awareness creation and vaccination against hepatitis B and hepatitis A to reduce the risk of development of liver cancer among the populace.
Effects of industrial effluents on the quality of water in Namanve stream, Kampala Industrial and Business Park, Uganda
(BMC Research Notes, 2020) Christopher, Angiro; Patrick, P’Odyek Abila; Timothy, Omara
Objective: Kampala Industrial and Business Park (KIBP) is one of the premier and the most successful Ugandan indus‑ trial complexes that impact the inner Murchison bay of Lake Victoria. The current study aimed at evaluating the effect of industrial effluents on the physicochemical and microbiological quality of water taken from four different sites along Namanve stream in KIBP, Wakiso district, Uganda. Results: All the water quality parameters were below WHO maximum permissible limits except turbidity, electrical conductivity and Escherichia coli count. Mean values of the monitored water quality parameters increased from the point of effluent discharge downstream of Namanve stream.
Heavy metal contamination of sediments from an exoreic African great lakes’ shores (Port bell, Lake Victoria), Uganda
(Pollutants, 2022-09-27) Gabson, Baguma; Andrew, Musasizi; Hannington, Twinomuhwezi; Allan, Gonzaga; Caroline, K. Nakiguli; Patrick, Onen; Christopher, Angiro; Augastine, Okwir; Boniface, Opio; Thomas, Otema; Daniel, Ocira; Ivan, Byaruhanga; Eric, Nirigiyimana; Timothy, Omara
Lake Victoria (L. Victoria) is the largest African tropical and freshwater lake, with one of the highest pollution levels, globally. It is shared among Uganda, Kenya and Tanzania, but it is drained only by the river Nile, the longest river in Africa. Though environmental studies have been conducted in the lake, investigations of the heavy metals (HMs) contamination of sediments from fish landing sites and ports on the Ugandan portion of L. Victoria are limited. In this study, sediments of an urban, industrial and fish landing site (Port Bell) on L. Victoria, Uganda was investigated to establish its HMs pollution levels and potential health risks to humans and ecosystems. Sediment samples were collected in triplicate (n = 9) from three different points of Port Bell, digested and analyzed using atomic absorption spectrometry for the presence of these HMs: copper (Cu), lead (Pb), cadmium (Cd) and chromium (Cr). The average daily dose through dermal contact and hazard quotient (HQ) were calculated to assess the health risk that is associated with dredging works (lake sand mining). Four geochemical enrichment indices: contamination factor (CF), geo-accumulation index (Igeo), pollution load index (PLI) and potential ecological risk (PERI) were used to quantify the contamination of the HMs in the sediments. The results showed that the mean HM content of the samples ranged from: 6.111 ± 0.01 to 7.111 ± 0.002 mg/kg for Cu; from 40.222 ± 0.003 to 44.212 ± 0.002 mg/kg for Pb; from 0.352 ± 0.007 to 0.522 ± 0.010 mg/kg for Cr; from 3.002 ± 0.002 to 3.453 ± 0.003 mg/kg for Cd. Health risk assessments indicated that there are no discernible non-carcinogenic health risks that could arise from the dredging works that are conducted in the study area as the indices were all below one. The contamination factors that were obtained suggest that Cd has reached a state of severe enrichment in the sediments (CF > 6). An assessment using Igeo established that the sediments were not contaminated with regards to Cu and Cr, but they exhibited low-to-median and median contamination with respect to Pb and Cd, respectively. Though the pollution load indices show that the contamination levels raise no serious concerns, the potential ecological risk indices show that there is considerable pollution of the Port Bell sediments, particularly with regard to Cd. Upon examination using multivariate statistical analyses, Cd and Cr showed a strong correlation which alluded to their introduction from anthropogenic sources. Based on the sedimentary HMs concentrations and the environmental indices that are employed in this study, it is recommended that the spatial variations in the concentrations of the HMs in water, sediments and biota should be monitored.
Lacustrine cyanobacteria, algal blooms and cyanotoxins in east Africa: implications for human and ecological health protection
(Phycology, 2023-02) Timothy, Omara; Christine, Betty Nagawa; Christine, Kyarimpa; Stefan, Böhmdorfer; Thomas, Rosenau; Solomon, Omwoma Lugasi; Henry, Matovu; Silver, Odongo; Patrick, Ssebugere
Advected cyanobacteria, algal blooms and cyanotoxins have been increasingly detected in freshwater ecosystems. This review gives an insight into the present state of knowledge on the taxonomy, dynamics, toxic effects, human and ecological health implications of cyanobacteria, algal blooms and cyanotoxins in the East African Community lakes. The major toxigenic microalgae in East African lakes include Microcystis, Arthrospira, Dolichospermum, Planktolyngbya and Anabaenopsis species. Anatoxin-a, homoanatoxin-a, microcystins (MCs), cylindrospermopsin and nodularin have been quantified in water from below method detection limits to 81 μg L−1, with peak concentrations characteristically reported for the wet season. In whole fish, gut, liver and muscles, MCs have been found at concentrations of 2.4 to 1479.24 μg kg−1, which can pose human health risks to a daily consumer. While there have been no reported cases of cyanotoxin-related poisoning in humans, MCs and anatoxin-a (up to 0.0514 μg kg−1) have been identified as the proximal cause of indiscriminate fish kills and epornitic mortality of algivorous Phoeniconaias minor (lesser flamingos). With the unequivocal increase in climate change and variability, algal blooms and cyanotoxins will increase in frequency and severity, and this will necessitate swift action towards the mitigation of nutrient-rich pollutants loading into lakes in the region.
Medicinal plants used in the management of sexual dysfunction, infertility and improving virility in the east African community: a systematic review
(Evidence-Based Complementary and Alternative Medicine, 2023-08) Christine, Kyarimpa; Christine, Betty Nagawa; Timothy, Omara; Silver, Odongo; Patrick, Ssebugere; Solomon, Omwoma Lugasi; Ivan, Gumula
Sexual disorders such as erectile dysfunction (ED), sterility, and sexual inappetence represent some of the complex reproductive challenges that require addressing the underlying causes. Te aim of this paper was to systematically synthesize literature on the ethnobotany, phytochemistry, bioactivities, and safety of plants used as remedies for managing sexual dysfunction and infertility, and improving fertility and virility in the EAC. Trough an extensive review conducted in multidisciplinary electronic databases, 171 plant species were identifed to have been reported for the management of sexual inappetence (i.e., used as aphrodisiacs, 39.4%), ED (35.9%), infertility (18.7%), and increasing fertility (6.0%). Te most used plants are Mondia whitei, Acalypha villicaulis, Combretum illairii, Erythrina abyssinica, Pappea capensis, Rhus vulgaris, and Warburgia ugandensis while roots (44.9%), leaves (21.8%), stem and root barks (16.7%) of shrubs (35%), trees (31%), herbs (26%), and climbers (8%) are the preferred organs for making decoctions (69%). Te research strides to date indicate that Citropsis articulata, Cola acuminata, Ekebergia capensis, Plumbago zeylanica, Tarenna graveolens, Urtica massaica, and Zingiber ofcinale have been assessed for their bioactivity. Te majority (71.4%) of the plants either increased testosterone levels and mounting frequency or elicited prosexual stimulatory efects in male rats. More studies investigating the relevant pharmacological activities (aphrodisiac, fertility, and phosphodiesterase-5 inhibitory activities), safety aspects, responsible compounds, and clinical studies are warranted to establish the pharmacological potential of the unstudied species and elucidate the mechanism of action of the bioactive compounds.
Optimization of Pyrolysis and Selected Physicochemical Properties of Groundnut Shells, Coffee and Rice Husks for Biochar Production
(Jordan Journal of Mechanical and Industrial Engineering, 2023-09) John, Chrysostom Opedun; William, Wanasolo; Aldo, Okullo Apita; Timothy, Omara
Biochar is a solid biofuel that can be obtained from pyrolysis of lignocellulosic feedstocks. In this study, pyrolysis of agricultural wastes (groundnut shells, coffee and rice husks) and their physiochemical characterization was done. Parameters that influenced biochar yields were optimized using response surface methodology and Box-Behnken design. The results obtained showed that rice husks had the highest ash and total solids content of 22.94% and 89.54%, respectively. Coffee husks had the lowest ash and total solids (1.58% and 87.69%) but the highest cellulose content (40.45%). Groundnut shells and rice husks had mean cellulose contents of 28.28% and 20.81%. Moisture content was stable across all the biomass samples with 10.46%, 12.31% and 12.49% recorded for rice and coffee husks, and groundnut shells. Basing on the overall interactive effect of particle size, moisture and cellulose contents, the most optimal interaction that yielded the highest quantity of biochar was found to be at 0.36 mm, 10.18% and 31.51% for particle size, moisture and cellulose contents, respectively. In these interactions, cellulose levels corresponded with groundnut shells as the best biomass material for producing biochar. The study recommends the use of ground nut shells for pyrolysis to produce high yields of biochar for industrial and agricultural applications.
Physicochemical quality of water and health risks associated with consumption of African lung fish (Protopterus annectens) from Nyabarongo and Nyabugogo rivers, Rwanda
(BMC research notes, 2020) Timothy, Omara; Papias, Nteziyaremye; Solomon, Akaganyira; Dickens, Waswa Opio; Lucy, Nyambura Karanja; Decrah, Moraa Nyangena; Betty, Jematia Kiptui; Remish, Ogwang; Stephen, Mark Epiaka; Abigael, Jepchirchir; Alfayo, Maiyo
Objective: To determine the quality of water, heavy metal content of edible muscles of a piscivorous fish (Protopterus annectens) and assess the health risks associated with using water and consumption of P. annectens from Nyabarongo and Nyabugogo rivers of Rwanda. Results: All the water quality parameters were within World Health Organization’s acceptable limits except total nitrogen, iron, manganese and lead levels. Edible muscles of Protopterus annectens contained 272.8 ± 0.36, 292.2 ± 0.25, 8.8 ± 0.36, 135.2 ± 0.15, 148.0 ± 0.21 and 432. 0 ± 0.50 mg/kg of iron, manganese, copper, zinc, chromium and lead at Ruliba station and 336.0 ± 0.70, 302.6 ± 1.22, 6.4 ± 0.26, 44.7 ± 0.20, 138.2 ± 0.17 and 302.4 ± 1.50 mg/kg of iron, manganese, copper, zinc, chromium and lead at Kirinda bridge of Nyabarongo river. Health risk assessments indi‑ cated that though ingestion and dermal contact with heavy metals in water from the rivers may not cause obvious health effects, consumption of Protopterus annectens from Nyabarongo river may lead to deleterious health effects.