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Item Public Perception of Climate Risk and Adaptation in Tanzania: a Systematic Review(Tanzania Journal of Agricultural Sciences, 2023-12-30) Nyinondi, P.S; Sospeter, M.E.Climate change is a pressing global challenge of the 21st century, with impacts including global warming, drought, famine, floods, tropical storms, and cyclones. One of the biggest challenges to mitigating climate change is people's perception of its risks. This study provides valuable insights on the public perception of climate risk and adaptation in Tanzania through a systematic review of peer-reviewed papers. The search was conducted using keywords related to climate change awareness, knowledge, perception, attitude, and risk adaptation from the Sokoine University of Agriculture Institutional repository (SUAIR) for publications between 2010 and 2022, 48 peer reviewed articles were reviewed. The review found that there is a high level of awareness (87.5%) of climate change, with many (77%) recognizing its impacts on their daily lives in terms of economic activities and gender roles. However, the perception of climate risk varies depending on factors such as gender, location, and socioeconomic status. For example, people living in rural areas perceived climate risks such as floods and drought more than those in urban areas did. Attitudes towards climate change adaptation also vary among different groups, with some people such as farmers more resilient and willing to adapt than pastoralists, people living in urban areas than people living in rural areas. The review identifies knowledge gaps in understanding the causes and impacts of climate change. Overall, this systematic review provides a comprehensive picture of current knowledge and understanding of the public perception of risk adaptation in Tanzania, highlighting areas for further research and policy action.Item Land-use/land-cover change in the Ngerengere River Catchment, Tanzania: Insights from 2004 to 2034(ACCSCIENCE PUBLISHING, 2025-07-21) Nkinda, Rose; Ojija, Fredrick,; Bacaro,Giovanni; Malunguja, GisanduLand use and land cover (LULC) surrounding the Ngerengere River, Tanzania, which is a crucial water source, has led to a rapid decline in vegetated areas. Understanding these changes is vital for informed decision- making and sustainable river catchment management. This study assessed historical LULC trends from 2004 to 2024, projected the current trend of change to 2034, and analyzed the human activities driving the trends using Landsat TM imagery. The study utilized both spatial and non-spatial datasets from primary sources (Landsat imagery via Google Earth Engine and field surveys) and secondary sources (literature and government reports). Landsat 5 (2004) and Landsat 8 (2014, 2024) images were processed using Arc-GIS and QGIS to minimize cloud interference. Land cover classification combined unsupervised and supervised methods, validated with ground reference points collected through GPS. A rule-based classification system used spectral indices to identify land cover types. Classified maps were visualized and exported for further analysis. Furthermore, systematic field visits were conducted along the catchment to assess human land use activities, that is, agriculture, settlements, and deforestation. Results revealed a 17.6% decline in sparse vegetation between 2004 and 2014, and a further 27.01% decrease from 2014 to 2024. Bare land increased by 8.58% over the two decades. Built-up areas rose from 0.67% in 2004 to 5.44% in 2014, then dropped to 2.1% in 2024. In contrast, dense vegetation increased from 0.04% in 2004 to 7.13% in 2024. Overall, the land cover projection for 2034 indicates continued ecological transformation within the Ngerengere River catchment. These shifts, primarily driven by agricultural expansion and deforestation, underscore the urgent need for sustainable land management. The significant vegetation cover decline in the catchment is largely due to agricultural encroachment into forested areas.Item Development of Internet of Things-Based System for Monitoring and Controlling the Water Quality in Small-Scale Aquaculture.(MUST Journal of Research and Development (MJRD), 2022-12-28) Nyoni, Abbas; Minga, Lusajo; Kusyama, Sadiki LameckWater quality is an essential factor for any successful aquaculture project. For high productivity from aquaculture, critical water quality parameters such as temperature, pH, dissolved oxygen, salinity, and turbidity must be kept in the optimum range. Temperature is the second-most critical water quality parameter after dissolved oxygen. Tropical fish prefer temperatures ranging from 250c to 320c. This study designed and implemented a system prototype for monitoring and controlling water temperature in an aquaculture environment based on the Internet of Things (IoT). The system comprises temperature sensors, a NodeMCU Esp8266 Microcontroller, a 2-channel relay switch, a liquid-crystal display, a cooling fan, a water heater, and a mobile application. The temperature sensor immersed in a fish pond collects the pond's temperature. The collected temperature data from fish ponds is sent to the microcontroller, a NodeMCU Esp8266, for processing and transmission to the cloud server. The Blynk Cloud IoT platform was used for data visualisation and controlling actuators. The system users could access data through the Blynk Mobile application installed on a smartphone. The system automatically switches ON the cooling fan to cool the water when the temperature is above 32oc and switches ON the water heater when the temperature is below 25oc. The system was tested both in the laboratory and in field to evaluate the system's performance in detecting pond temperature and data dissemination to the users. This study's findings have proved the system's capability in data acquisition with accuracy and efficiency. In addition, the results have shown that the system can effectively control pond temperature.Item What Happens After Conservation and Management Donors Leave? A Before and After Study of Coral Reef Ecology and Stakeholder Perceptions of Management Benefits(CrossMark, 2015-10-15) McClanahan, Timothy R.; Muthiga, Nyawira A.; Abunge, Caroline.; Kamukuru, Albogast T.; Mwakalapa, Eliezer.; Kalombo, HassanThe coral reefs of Tanga, Tanzania were recognized as a national conservation priority in the early 1970s, but the lack of a management response led to damage by dynamite, beach seines, and high numbers of fishers until the mid 1990s. Subsequently, an Irish Aid funded IUCN Eastern Africa program operated from 1994 to mid 2007 to implement increased management aimed at reducing these impacts. The main effects of this management were to establish collaborative management areas, reduce dynamite and seine net fishing, and establish small community fisheries closures beginning in 1996. The ecology of the coral reefs was studied just prior to the initiation of this management in 1996, during, 2004, and a few years after the project ended in 2010. The perceptions of resource users towards management options were evaluated in 2010. The ecological studies indicated that the biomass of fish rose continuously during this period from 260 to 770 kg/ha but the small closures were no different from the non-closure areas. The benthic community studies indicate stability in the coral cover and community composition and an increase in coralline algae and topographic complexity over time. The lack of change in the coral community suggests resilience to various disturbances including fisheries management and the warm temperature anomaly of 1998. These results indicate that some aspects of the management program had been ecologically successful even after the donor program ended. Moreover, the increased compliance with seine net use and dynamite restrictions were the most likely factors causing this increase in fish biomass and not the closures. Resource users interviewed in 2010 were supportive of gear restrictions but there was considerable between-community disagreement over the value of specific restrictions. The social-ecological results suggest that increased compliance with gear restrictions is largely responsible for the improvements in reef ecology and is a high priority for future management programsItem Aflatoxin production mechanisms and management in the maize cropping systems of sub-Saharan Africa(CAB International, 2025-09-11) Kwigizile, Owekisha H.; Mng’ong’o ,Marco E.; Mushongi , Arnold; Mbega Ernest; Mashamba,PhilipoIn sub-Saharan African countries, the maize crop is a major staple food crop, providing up to 70% of the population’s total caloric intake. Aflatoxins, toxic secondary metabolites primarily produced by Aspergillus flavus and Aspergillus parasiticus, pose significant threats to food safety, public health, and agricultural economies in sub-Saharan Africa (SSA), where maize is a staple crop. This review synthesizes current knowledge on the mechanisms of aflatoxin production and its management within maize cropping systems of SSA. The occurrence and severity of aflatoxin contamination are influenced by multiple factors, including high temperatures, drought stress, insect damage, poor post-harvest handling, and inadequate storage conditions. Maize has been linked to being contaminated by roughly eighteen (18) different forms of aflatoxins, which are severely poisonous, and contribute to public health issues. The review explores the biological and environmental triggers of aflatoxin biosynthesis, highlighting molecular pathways and fungal-host interactions. Additionally, it evaluates integrated management strategies encompassing host resistance, good agricultural practices, biocontrol agents (such as Aflasafe), proper harvesting, drying, and storage techniques. Socio-economic and institutional barriers to effective aflatoxin control are also discussed, along with policy and research recommendations. The review also emphasizes on the necessity to apply novel and existing techniques to prevent aflatoxin. The study featured the need for a multidisciplinary and region-specific approach to sustainably mitigate aflatoxin risks in SSA. Best bet recommendations are provided given different levels of scenarios at the farmer, farm plot, maize farming systems, and eventually the nodes across the entire maize value chain.Item Market Performance of Avocado Fruits among Smallholder Farmers in Southern Highlands of Tanzania(Scientific Research Publishing Inc., 2025-02-28) Mlengera, Ndabhemeye.; Katunzi, Adolph.; Marijani, Issaya.; Nzilano, Billes.; Mng’ong’o, Marco.; Mvile, Baraka.This study was designed to determine factors that influence market performance of avocado fruits among smallholder farmers in Mbeya and Songwe regions. A cross section research design entailing 209 farmers from five (5) districts of two (2) regions and 15 key informants; 5 local service providers (LSP), 5 traders/brokers and 5 district extension officers (DEO) were involved in the study. Random selection procedures were used to select avocado producers and purposive selection procedures were used to select key informants. The study employed survey questionnaires to collect data from avocado farmers and structured interview to collect data from key informants. Collected data were analyzed with an aid of descriptive statistics and linear regression model was used to determine significant factors that determine market prices of avocado fruits among smallholder farmers. The demographic characteristics of avocado farmers showed that; 61.2% of farmers had age between 36 to 59 years old, 84.7% were married, 74.6% had primary education level, average number of 5 members of the family, average 4.3 acres of owned land and 1.8 acres planted with avocado. Moreover, findings showed that 90.9% grew improved avocado varieties. Farm gate (88.5%) was the major market outlet chosen by avocado farmers. Local merchants and processors were the major buyers of the produced avocado. Results from linear regression analysis showed that variety grown (P < 0.05), location (P < 0.05), farm size (P < 0.05) and farmers experience (P < 0.05) were factors that statistically influenced market prices for avocado fruits. The study concluded that despite the remarkable contributions to livelihood of the farmers yet, it is highly fragile on market prices. Therefore, the study recommends the need to establish market systems that will govern avocado fruits marketing for sustainability of the sub-sector.Item Assessment of Heavy Metals in Wild and Farmed Tilapia (Oreochromis Niloticus) on Lake Kariba, Zambia: Implications for Human and Fish Health(Taylor & Francis Group, 2021-08-20) Simukoko, Chalumba Kachusi.; Mwakalapa, Eliezer Brown.; Bwalya, Patricia.; Muzandu, Kaampwe.; Berg, Vidar.; Mutoloki, Stephen.; Polder, Anuschka.; Lyche, Jan LudvigThe aim of this study was to assess the levels of heavy metals in both wild and farmed tilapia on Lake Kariba in Zambia and to evaluate the impact of intensive fish farming on wild tilapia. Three sites for wild fish (2 distant and 1 proximal to fish farms) and two fish farms were selected. One hundred fish (52 from distant sites; 20 near fish farms; 28 farmed fish) were sampled and muscle tissues excised for analysis of heavy metals (Mg, Fe, Zn, Al, Cu, Se, Co, Mo, As, Cr, V, Ni, Hg, Pb, Li, Cd, and Ag) by acid (HNO3) digestion and ICP-MS. All metals were found to be below the maximum limits (MLs) set by WHO/EU. Essential metals were higher in farmed tilapia, whereas non-essential metals were higher in wild tilapia. Significantly higher levels of essential metals were found in wild fish near the fish farms than those distant from the farms. Estimated weekly intake (EWI) for all metals were less than the provisional tolerable weekly intakes (PTWI). Target hazard quotients (THQ) and Hazard Indices (HI)<1 were indicating no health risks from a lifetime of fish consumption. Selenium Health Benefit Value (HBVSe) was positive for all locations, indicating protective effects of selenium against mercury in fish. Total cancer risk (CR) due to As, Cr, Cd, Ni and Pb was less than 1 × 10−4, indicating less than 1 in 10,000 carcinogenic risk from a lifetime consumption of tilapia from Lake Kariba. Hg levels (0.021 mg/kg) in wild tilapia at site 1 were higher than the Environmental quality standard (EQS = 0.020 mg/kg) set by EU, indicating possible risk of adverse effects to fish. Except for Hg, levels of metals in fish were safe for human consumption and had no adverse effects on fishItem Non-genetic Factors Influence Birth Weight of Friesian and Friesian x Fipa Cattle Calves in One Highland Farm of Tanzania(Asian Journal of Research in Animal and Veterinary Sciences, 2024-11-27) Mwaipopo, Lokoo C.; Mpemba, Charles H.; Chang’a, Edwin P.; Guni, Fadhili S.; Mutabazi, Gryson K.; Mng’ong’o, Marco E.Calving records were extracted from record books at TALIRI Uyole farm from 2013 - 2022, to study and determine the influence of breed, sex, season of birth, and year of birth on weight at birth of pure Friesian and its crosses (F1 Friesian x Fipa and 75% Friesian x Fipa) calves which, are grazed under natural pasture. The least squares mean of BWT in Friesian, F1 and 75% calves were 25.51±0.98 kg, 26.45 ± 1.23 and 25.26 ± 0.94, respectively. It was observed that sex of calf and year of birth had significant (P0.05) with variation in mean birth weight of its crosses at birth, whereas variations on BWT at birth were noted in F1, which had higher BWT compared to other breed/cross, and calf born in the wet season showed slightly higher BWT than calves born in the dry season. Under natural pasture grazing, the available fodder was of poor quality, and no agronomic management practices were followed, whereas it was reverse in the wet season, thus the nutrient demand for body maintenance, reproduction, and production activities are impairedItem Advances and Trends in Ecological Organic Agriculture (EOA) Technologies and Research on Fruit Vegetables Produced in Tanzania(CAB International, 2022-05-17) Shango, Abdul J.; Maswi, Philip B.; Malya, Rashid B.; Maro, Janet F.; Mwaipopo, Rehema E.; Majubwa, Ramadhani O.; Kilewa, Ramadhan A.; Philipo, Mashamba L.Ecological organic agriculture (EOA) is a holistic production management system that can solve many problems in the vegetable crops’ value chain (VC). It is, however, unclear about the EOA technologies for the fruit vegetable VC that have already been validated or are in process of validation in Tanzania. A systematic literature search on EOA technologies relevant in Tanzania was conducted for research articles from 2010 until 2021. Most 10(30.4%) studies on fruit vegetables were equally distributed each 5(15.2%) in the years 2019 and 2020, respectively. A total of 33 records on fruit vegetables covered eight (8) regions of mainland Tanzania and one (1) region from the island of Zanzibar. Most 18(55%) studies were conducted in the Morogoro region. Based on the fruit vegetable VC, 26(68.4%) studies were for field establishment and management. Nine (9) key areas were identified, where most 9(27.3%) studies were on crop productivity and protection. Seventeen (17) EOA technologies were applied in fruit vegetables, mostly biocontrol 7(21%) in tomatoes. Overall, 27(81.8%) studies only researched the EOA technologies, while 3(9.1%) studies validated the EOA technologies, 2(6.1%) researches were in progress, and 1(3.0%) was progressing validation. Few 3(9.1%) studies portrayed the involvement of youth and women using the principles of participatory action research (PAR) during the validation. Generally, the EOA technologies are readily available, require minimal skills and labour, are cost-effective, sustainable, easily implementable in the fruit vegetable VC and can be simply accessed and utilized in cultivating organic fruit vegetables.Item Underutilised Oyster Nut (Telfairia pedata): Farmers’ Knowledge, Practices and Utilisation in Northern Tanzania(MJRD, 2025-03-31) Shayo,Philipina F; Mbega,Ernest R; Treydte,Anna COyster nut [Telfairia pedata (Smiths ex Sim)] Hook is a regularly cultivated crop in East African countries such as Tanzania (including Zanzibar Island), Uganda, Angola, Mozambique, and along Kenya’s coast, which is regarded to be underutilised. Despite its relevance to small-scale farmers in terms of conservation, income creation and food security, little is known about the farmer’s knowledge, practices and utilisation in Northern Tanzania. Therefore, this study aimed at investigating aspects of its production, including farmers’ practices, utilisation and preferences. Data collection was carried out through semi-structured questionnaires in the regions of Arusha, Kilimanjaro and Tanga. Descriptive analysis was done whereby frequencies, means and percentages were calculated using SPSS from the farmers’ responses. The results on oyster nut preferences, knowledge, cultivation and utilisation were presented in the form of tables and graphs. The findings revealed that 87% of respondents who were knowledgeable about oyster nuts were female, 89% of interviewed farmers grew the nuts on inherited family lands, 24% of respondents stored oyster nuts in perforated plastic bags, and 90% of the farmers used recycled seeds as their primary method of propagation without the use of any agricultural inputs. Conclusively, the study gives significant baseline data for future research on oyster nuts and development projects in Tanzania to enhance its conservation and sustainable usage while ensuring nutritional security for the majority of resource-poor people.Item The Role of Conservation Agriculture in Enhancing Biodiversity and Common Beans Productivity(Elsevier B.V, 2026) Mng’ong’o, Marco E.; Mwaipopo, Rehema E.; Ojija, Fredrick.; Matimbwa, Hadija.Conservation of biodiversity in agricultural landscapes is vital for maintaining ecosystem stability and resilience. Conservation agriculture, a sustainable farming approach that involves minimum tillage and reduced use of synthetic pesticides, herbicides, and growth promoters, has gained attention as a potential strategy to enhance biodiversity and reduce production costs. This study investigated the role of conservation agriculture in enhancing biodiversity and common bean productivity in Tanzania. The study compared plots practicing conservation agriculture (minimum tillage and reduced agrochemical use) with those using conventional farming methods. Biodiversity metrics, that is, earthworm populations, bird species richness, bird nest abundance, bird species diversity, bee visitation rates, and bean yield were assessed. The results showed significant positive effects of conservation agriculture on biodiversity, emphasizing its potential role in promoting sustainable agriculture, biodiversity conservation, and household improvement due to reduced production costs and increased yield per unit area. Earthworms per meter square observed to increase from 12 in the non-conservation plots to 34 in the conservation plots, which is likely to improve nutrient cycling and productivity. Furthermore, conservation plots had a higher number of bird species flying around (36− 76) compared with 14–32 in nonconservation plots (4000 m2 ) at 50 % bean flowering. The number of bird nests observed in the two plots during bean harvesting varied significantly (PItem Is The Hybrid Tiger Trout A Suitable Recipient for the Transplantation of Salmonid Spermatogonia?(Elsevier B.V., 2025-04-17) Marinovi, Zoran.; Luji, Jelena.; Hoitsy, Gyorgy.; Hoitsy, Boglarka.; Hoitsy, Marton. s.; Scekic, Ilija.; Balogh Reka Eniko.; Shimo, Seleman Samwel.; Lefler, Kinga Katalin.; Kovacs, Balazs.; Urbanyi, Bela.; Horvath, AkoIn this study, we tested the utility of sterile tiger trout, an interspecific hybrid of a brown trout (Salmo trutta m. fario) female and a brook trout (Salvelinus fontinalis) male primarily bred for aquaculture, as a potential recipient for the surrogate production of other salmonid fish. The sterility of adult tiger trouts was confirmed as spermatogenesis progressed further from the mitotic phase in only one male, while only a few females contained vitellogenic oocytes. We transplanted spermatogonial stem cells (SSCs) from rainbow trout into larvae (total of 371 recipients) and adult (total of 15 recipients) tiger trout. Recipients were reared up to 3 years posttransplantation (ypt), and transplantation success was tested by (1) the production of functional gametes, (2) development of recipient gonads past the baseline development assessed through histological analyses and (3) detection of donor cells inside of recipient gonads through molecular analyses. Gametes were produced only by one male recipient in which SSCs were transplanted as a larva. This male displayed clear signs of a developed testis, and rainbow trout DNA was detected in the testicular samples. Rainbow trout DNA was detected in three additional male recipients (injected as larvae), however, none of these individuals displayed signs of gametogenesis progression at 3 ypt. Furthermore, recipients injected as adults did not show any progression of gametogenesis, nor the presence of rainbow trout DNA in the gonads at 2.5 ypt. Milt obtained by the mentioned recipient was used to fertilize rainbow trout eggs which led to the production of donor-derived offspring. All viable offspring displayed phenotypical characteristics of rainbow trout which was further corroborated by molecular analyses. In conclusion, we display that the hybrid tiger trout can be used for the surrogate production of other salmonid fish, especially trout species which are closely related.Item Persistent Organic Pollutants (Pops) and Per- And Polyfluoroalkyl Substances (Pfass) in Liver From Wild and Farmed Tilapia (Oreochromis Niloticus) From Lake Kariba, Zambia: Levels and Geographic Trends and Considerations in Relation to Environmental Quality Standards (Eqss)(Elsevier Inc., 2023-05-22) Simukoko, Chalumba Kachusi.; Mwakalapa, Eliezer Brown.; Muzandu, Kaampwe.; Mutoloki, Stephen.; Evensen, Øystein.; Ræder, Erik Magnus.; Müller, Mette Bjørge.; Polder, Anuschka Lyche,; Jan Ludvig.The current study was carried out to investigate a wide variety of persistent organic pollutants (POPs) in wild and farmed tilapia (Oreochromis niloticus) in Lake Kariba, Zambia, and assess levels of POPs in relation to Environmental Quality Standards (EQSs). Concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyls (PBDEs), and perfluoroalkyl substances (PFASs) were determined in liver samples of tilapia. PFASs compounds PFOS, PFDA and PFNA were only detected in wild fish, with the highest median PFOS levels in site 1 (0.66 ng/g ww). Concentrations of POPs were in general highest in wild tilapia. The highest median ∑DDTs (93 and 81 ng/g lw) were found in wild tilapia from sites 1 and 2, respectively 165 km and 100 km west of the fish farms. Lower DDE/DDT ratios in sites 1 and 3 may indicate relatively recent exposure to DDT. The highest median of ∑17PCBs (3.2 ng/g lw) and ∑10PBDEs (8.1 ng/g lw) were found in wild tilapia from sites 1 and 2, respectively. The dominating PCB congeners were PCB-118, -138, − 153 and − 180 and for PBDEs, BDE-47, -154, and − 209. In 78% of wild fish and 8% of farmed fish ∑6PBDE concentrations were above EQSbiota limits set by the EU. This warrants further studiesItem Integrated Agricultural Landscape Management: Case Study on Inclusive Innovation Processes, Monitoring and Evaluation in the Mbeya Region, Tanzania(SAGE, 2017) Malley, Zacharia J.; Malley, Zacharia J.; Buck, Louise.; Mwambene, Pius L.; Katambara, Zacharia.; Mng’ong’o, Marco.; Chambi, ConsolathaIntegrated landscape management is a process for achieving multiple objectives related to agricultural production, ecosystem conservation, and sustainable natural resource management. These multiple livelihood functions are important features of an agricultural landscape in Mbeya, Tanzania. Due to environmental damage caused by agricultural expansion and charcoal burning, a process called integrated agricultural landscape management (IALM) was implemented to address this problem. This encompassed the identification and involvement of a range of key landscape actors and processes like awareness creation and joint problem analysis, solution framing, learning, planning and implementation of actions, and monitoring and evaluation. A multistakeholder innovation platform was formed for creating a coordination mechanism, common understanding, vision and goals, and networking. Fifty IALM ideas were identified and six selected by the stakeholders. Outcomes of using the IALM process included policy recommendations, joint learning, and innovative actions and were codeveloped, implemented, monitored, and evaluated with the local communities.Item Accumulation and Distribution of Mercury in Agricultural Soils, Food Crops and Associated Health Risks: a Case Study of Shenda Gold Mine-Geita Tanzania.(Elsevier, 2023-02-18) Sanga, Tumikia R.; Maseka, Kenneth K.; Ponraj, Mohanadoss; Tungaraza, Clavery; Mng’ong’o, Marco E.; Mwakalapa, Eliezer B.Contamination of the environment and food stuff by potentially harmful elements (PHEs) has become a serious concern due to the associated health risks to the population. In the present study total mercury (Hg) levels in soil and food crops from farms around Shenda gold mine in Geita Tanzania was determined by Cold Vapor Atomic Fluorescence Spectrometry (CVAFS). Generally, it was found that there was significant different of Hg content in soil and food crops (P < 0.05) among studied sites. The total Hg concentrations determined were in the ranges of; soils (0.003-0.1220 mg/kg), rice (0.0752-0.1587 mg/kg) and vegetables (0.0556-0.3439 mg/kg) all measurement were based on dry weight basis (dw). Total Hg levels in soil were compared with the maximum allowable concentration (MAC) set by Tanzania Bureau of Standards (TBS) and United Kingdom (UK). All studied soil samples were within acceptable range (2 mg/kg) set by TBS and UK (1 mg/kg). Total Hg contents in food crop samples were compared with Chinese MAC of Hg (0. 01 and 0.02 mg/kg for leafy vegetables and grains respectively in a fresh weight basis). It was observed that Hg contents in potato leaves, pumpkin leaves and Chinese cabbage were within the MAC while Hg levels in cassava leaves and rice grains exceeded the MAC. In addition, Hg associated health risks to consumers of contaminated foods for residents around Shenda gold mine were estimated. The estimated weekly intake (EWI) of Hg due to consumption of rice grain was above the provisional tolerable weekly intake (PTWI) set by FAO/WHO (1.6 mg/kg bw/week) while the EWI due to consumption of leafy vegetables were below the PTWI. Target hazard quotient (THQ) was < 1 due to consumption of vegetables while THQ value for rice was > 1, indicating a potential non-carcinogenic risk to adult population from the consumption of rice grain from the study area. Therefore, people living near Shenda goldmine might be potential victim of Hg accumulation in soil and food crops, thus necessary management options have to be in place.Item Bio-Concentration and Translocation of Chromium in Soil-Plant System: Health Risks in Usangu Agro-Ecosystem(Elsevier, 2023-06-10) Mng’ong’o, Marco E.; Mshora, Abubakar M.; Christopher, Msigwa; Komanya, Absalom; Shimo, SamwelDetermination and analysis of total chromium (Cr) in soil and plant tissues help estimate the associated health risk; however, this might overestimate the risk because not all Cr from the soil is transported to above-ground plant tissues, mainly the edible part of most plants. Here we present the analysis of Cr partition in soils and paddy rice plant samples which currently missing in Usangu agro-ecosystem. The bio-concentration (BF) and translocation factors (TF) estimating the distribution and partitions of Cr in plant tissues (roots, straws, and grains), and associated environmentally and health risks were determined in Usangu agro-ecosystem. The Cr concentration in soils ranged from 4.58 to 42.76 mg/kg which was within maximum permissible limits (100 mg/ kg), with the total Cr in plants samples ranging from 12.88 to 57.34 mg/kg. It was found that straws and roots had higher Cr concentrations than grains indicating a less health risk in edible parts. The BF > 1 was observed in 83.3% of the studied sites indicating higher Cr uptakes by plants. Furthermore, TF < 1 was observed in 67.33% of the studied sites indicating more Cr accumulated in below-ground biomass (roots) than above-ground biomass (straws and grains) (33.33%), thus less risk to edible plant parts. This study indicates that high Cr in agricultural soils may accelerate Cr accumulation in plant tissues or above-ground plant biomass leading to health risks.Item Spatial Trends of Chlorinated Paraffins and Dechloranes in Air and Soil in a Tropical Urban, Suburban, and Rural Environment.(Elsevier, 2021-10-04) Nipen, M.; Vogt, Rolf David; Bohlin-Nizzetto, Pernilla; Borgå, Katrine; Mwakalapa, Eliezer Brown; Borgen, Anders Røsrud; Jørgensen, Susanne Jøntvedt; Ntapanta, Samwel Moses; Mmochi, Aviti John; Schlabach, Martin; Breivik, KnutThere are large knowledge gaps concerning environmental levels and fate of many organic pollutants, particularly for chemicals of emerging concern in tropical regions of the Global South. In this study, we investigated the levels of chlorinated paraffins (CPs) and dechloranes in air and soil in rural, suburban, and urban regions in and around Dar es Salaam, Tanzania. Samples were also collected near the city’s main municipal waste dumpsite and an electronic waste (e-waste) handling facility. In passive air samples, short chain CPs (SCCPs) dominated, with an average estimated concentration of 22 ng/m3, while medium chain CPs (MCCPs) had an average estimated concentration of 9 ng/m3. The average estimated air concentration of Σdechloranes (Dechlorane Plus (DP) + Dechlorane 602 + Dechlorane 603) was three to four orders of magnitudes lower, 2 pg/m3. In soil samples, MCCPs dominated with an average concentration of 640 ng/g dw, followed by SCCPs with an average concentration of 330 ng/g dw, and Σdechloranes with an average concentration of 0.9 ng/g dw. In both air and soil, DP was the dominating dechlorane compound. Urban pulses were observed for CPs and dechloranes in air and soil. CPs were in addition found in elevated levels at the municipal waste dumpsite and the e-waste handling facility, while DPs were found in elevated levels at the e-waste handling facility. This suggests that waste handling sites represent important emission sources for these pollutants. Investigations into seasonal trends and environmental fate of CPs and dechloranes showed that monsoonal rain patterns play a major role in governing air concentrations and mobility, particularly for the less volatile MCCPs and dechloranes. This study is the first to report levels of CPs in air from sub-Saharan Africa, and DP, Dechlorane 602, and Dechlorane 603 in soil from sub-Saharan AfricaItem Effects of cadmium uptake on growth and productivity of Chinese cabbage (Brassica rapa subsp. pekinensis) and pumpkin (Cucurbita moschata Duchesne) vegetables.(Elsevier, 2023-08-13) Sanga, Tumikia R.; Mwakalapa, Eliezer B.; Mng’ong’o, Marco; Kalugendo, Kokusima; Ponraj, Mohanadoss; Maseka, Kenneth K.Cadmium (Cd) is recognized as one of the most toxic elements to plants and humans when available in higher concentrations. In the present study, a pot experiment was carried out to investigate the effect of different Cd levels (0, 10, 20, 30, and 40 mg/kg) on the growth, production, and uptake of Cd using Chinese cabbage (Brassica rapa subsp. pekinensis) and pumpkin leaves (Cucurbita moschata Duchesne) vegetables. The study found significant differences (P < 0.05) in all growth parameters in the studied vegetables. The Cd treatments resulted in decreasing number of leaves, shoot fresh weight, shoot dry weight, and total dry weight in both vegetables compared to the control. The total dry weight of Chinese cabbage was decreased by 6.79%, 48.42%, 5.88%, and 5.43%, at 10, 20, 30, and 40 mg/kg respectively compared to the control. In pumpkin leaves total dry weight was decreased by 28.95%, 28.95%, 18.42%, and 14.47% at 10, 20, 30, and 40 mg/kg respectively compared to the control. Increase and decrease effects on root length were observed for all the vegetables. Pumpkin leaves showed increased root length at 10 mg/kg (61.39%), 20 mg/kg (17.87%), and 30 mg/kg (70.03%) while at 40 mg/kg, there was a decrease in root length by 20.13% as compared to the control. The root length of Chinese cabbage decreased by 25.05%, 8.4%, and 7.26% at 20 mg/kg, 30 mg/kg, and 40 mg/kg compared to the control except at 10 mg/kg which was found to be higher by 0.6% compared to the control. The Cd treatment in soil resulted in the increase of shoot Cd concentration in all the vegetables with maximum concentration observed at 20 mg/kg. Therefore, agricultural soil with elevated Cd levels will affect pumpkin and Chinese cabbage cultivation but also the consumption of such vegetables may result to toxic effects on human health.Item Optimized Method for Processing Avocado Seeds to Improve Selected Nutrients and Functional Values.(Food Science and Technology Research, 2020-08-25) Runyogote, Joseph; Chacha, Musa; Ndabikunze, Bernadette; Raymond, JofreyProbiotic Fermentation, Boiling, Soaking, Anti-Nutrients, Vitamins, Antioxidant Activity, Total Phenols The objective of this study was to develop an optimal processing technique capable of reducing antinutrients to acceptable levels, retain nutrients and functional values of avocado seeds for human consumption. Different processing conditions for probiotic fermentation, boiling and soaking techniques were studied to establish optimal processing conditions for the seeds. The antinutrients, antioxidant activity, total phenolics and selected nutrients of avocado seeds were analyzed using analytical standard methods.All processing techniques significantly (p < 0.05) reduced over 50 % of antinutrients. The highest total phenolics and antioxidant activity (IC50) were 33.3 mgGAE/g and 0.8 mg/mL respectively which were observed at a fermentation temperature of 37 oC. Soaking and boiling reduced the analyzed minerals to about 30 % whereas probiotic fermentation retained 100 % of minerals analyzed, ascorbic acid and α-tocopherol. Moreover, probiotic fermentation demonstrated the best results in comparison to boiling and soaking thus, considered as an optimal processing method for improving nutritional and functional values of avocado seedsItem Accumulation and distribution of mercury in agricultural soils, food crops and associated health risks: A case study of Shenda gold mine-Geita Tanzania.(ELSEVIER, 2023-02-18) Sanga, Tumikia R.; Maseka, Kenneth K.; Ponraj, Mohanadoss; Tungaraza, Clavery; Mng’ong’o, Marco E.; Mwakalapa, Eliezer B.Contamination of the environment and foodstuff by potentially harmful elements (PHEs) has become a serious concern due to the associated health risks to the population. In the present study total mercury (Hg) levels in soil and food crops from farms around Shenda gold mine in Geita Tanzania was determined by Cold Vapor Atomic Fluorescence Spectrometry (CVAFS). Generally, it was found that there was significant different of Hg content in soil and food crops (P < 0.05) among studied sites. The total Hg concentrations determined were in the ranges of; soils (0.003-0.1220 mg/kg), rice (0.0752-0.1587 mg/kg) and vegetables (0.0556-0.3439 mg/kg) all measurement were based on dry weight basis (dw). Total Hg levels in soil were compared with the maximum allowable concentration (MAC) set by Tanzania Bureau of Standards (TBS) and United Kingdom (UK). All studied soil samples were within acceptable range (2 mg/kg) set by TBS and UK (1 mg/kg). Total Hg contents in food crop samples were compared with Chinese MAC of Hg (0. 01 and 0.02 mg/kg for leafy vegetables and grains respectively in a fresh weight basis). It was observed that Hg contents in potato leaves, pumpkin leaves and Chinese cabbage were within the MAC while Hg levels in cassava leaves and rice grains exceeded the MAC. In addition, Hg associated health risks to consumers of contaminated foods for residents around Shenda gold mine were estimated. The estimated weekly intake (EWI) of Hg due to consumption of rice grain was above the provisional tolerable weekly intake (PTWI) set by FAO/WHO (1.6 mg/kg bw/week) while the EWI due to consumption of leafy vegetables were below the PTWI. Target hazard quotient (THQ) was < 1 due to consumption of vegetables while THQ value for rice was >1, indicating a potential non-carcinogenic risk to adult population from the consumption of rice grain from the study area. Therefore, people living near Shenda goldmine might be potential victim of Hg accumulation in soil and food crops, thus necessary management options have to be in place.