Research & reports
Peer-reviewed research and reports on community urban agriculture, food education, composting, welfare and more.
Theme
Critical findings
37 results(2 / 2)
Heavy Metals and Physicochemical Properties of Soils in Kano Urban Agricultural Lands
2014UM Dawaki, A. U. Dikko, SS Noma, U. Aliyu · Nigerian Journal of Basic and Applied Sciences · Nigeria
A study investigated the total, exchangeable, and soluble concentrations of heavy metals (Cu, Cr, Ni, Zn, Pb, Cd) in urban agricultural soils along three rivers (Challawa, Jakara, and Watari) in Kano, Nigeria. Cadmium concentrations at Jakara and Challawa exceeded maximum allowable concentrations in soils. Heavy metal concentrations were found to be significantly higher in areas irrigated with industrial and domestic sewage (Challawa and Jakara) compared to the control site (Watari).
Contamination & food safetyHealthPeri-urban agricultureHeavy metal content of selected African leafy vegetables planted in urban and peri-urban Nairobi, Kenya
2014A. N. Mutune, M. A. Makobe, Mary Abukutsa‐Onyango · African Journal of Environmental Science and Technology · Kenya (Nairobi)
This study analyzed heavy metal content in 10 common African leafy vegetables and their rhizosphere soils from 25 sites along Nairobi Rivers, Kenya. While soil metal concentrations were generally within WHO/FAO permissible levels, except for some cadmium instances, all metals except copper in vegetables exceeded recommended limits at a few sites. This indicates potential heavy metal absorption from industrial and domestic effluent.
Contamination & food safetyHealthPeri-urban agriculturePollution as a threat factor to urban food security in metropolitan Kano, Nigeria
2013Mansur Usman Dawaki, Abubakar U. Dikko, S. S. Noma, Umar Aliyu · Food and Energy Security · Nigeria
This study evaluated pollution risks to food security from urban agriculture in Kano, Nigeria, by sampling soil, water, and lettuce from two wastewater-irrigated sites (Challawa, Jakara) and a control site (Watari). Results showed all sites were contaminated with Cu, and the domestic wastewater site was slightly polluted with Pb and excessively polluted with Cd and Cr. Metal levels in irrigation waters exceeded recommended thresholds, and plants at the domestic wastewater site accumulated metal concentrations (Pb=26.21 mg/kg, Cd=1.03 mg/kg, Cr=28.63 mg/kg, Cu=2.66 mg/kg) that exceeded allowable limits in vegetables, indicating a human ingestion risk.
Contamination & food safetyHealthFood sovereignty & justicePollution of Water, Soil and Vegetables: Challenges to Growing Cities of Bahir Dar and Kombolcha, Amhara Region, Ethiopia
2013Mekonnen Getahun, Yihenew G. Selassie · Journal of Agricultural Science · Ethiopia
A study investigated the extent of contamination of soil, water, and vegetables from wastewater used for irrigation in urban agriculture in Bahir Dar and Kombolcha, Ethiopia. Soil, water, and vegetable samples were collected and analyzed. While heavy metal concentrations in soil were within permissible levels, wastewater samples showed high nitrate and phosphate levels, and boron concentrations in Borkena River and Lake Tana exceeded permissible limits for irrigation. Wastewater drained to Lake Tana exhibited high turbidity and very high BOD, and lettuce and Swiss chard accumulated higher levels of iron, manganese, and zinc.
Contamination & food safetyHealthUrban–rural linkageField assessment of cadmium, lead and zinc contamination of soils and leaf vegetables under urban and peri-urban agriculture in northern Nigeria
2012G. N. Egwu, John O. Agbenin · Archives of Agronomy and Soil Science · Nigeria
A study in northern Nigeria assessed cadmium, lead, and zinc contamination in soils and leaf vegetables (amaranthus, lettuce) irrigated with untreated wastewater. Total cadmium and zinc concentrations in soils exceeded safe limits, and lead and cadmium in edible portions of amaranthus and lettuce exceeded safe limits for human consumption by 7–17 times. The permissible limit for lead established for agricultural lands may not be suitable to ensure produce safety in urban and peri-urban agriculture in Kano.
Contamination & food safetyHealthPeri-urban agricultureConcentrations of Heavy Metals and Pesticide Residues in Leafy Vegetables and Implications for Peri-urban Farming in Nairobi, Kenya
2012Nancy Karanja, Mary Njenga, G.K. Mutua, Carl Johan Lagerkvist, E. Kutto, JJ Okello · Journal of Agriculture Food Systems and Community Development · Kenya (Nairobi)
A study in three peri-urban sites in Nairobi, Kenya, assessed heavy metal, nitrate, and pesticide residue levels in wastewater-irrigated kale. Elevated levels of boron, cobalt, chromium, copper, lead, zinc, and nickel were found in vegetables at two sites, with high soil loadings of nickel, arsenic, lead, chromium, copper, and zinc attributed to chicken manure. Pesticide residues of diazinon, cypermethrin, biternol, and profenofos exceeded permissible limits in kale at one site, suggesting consumers may ingest significant amounts of contaminants.
Contamination & food safetyHealthPeri-urban agricultureSuitability of urban wastes for crop production in Zaria, northern Nigeria: bioavailability and geochemical fractions of potentially toxic elements
2012Sebastian U. Ugbaje, John O. Agbenin · International Journal of Environmental Studies · Nigeria
A pot experiment in Zaria, northern Nigeria, evaluated the chemical forms and phytoavailability of Cr, Ni, and Pb in savannah soil amended with two urban wastes and planted with sorghum. While urban waste application increased total metal concentrations in the soil, only Pb uptake by sorghum increased, with no corresponding increases for Cr and Ni. A single application of urban wastes significantly increased Pb uptake by sorghum, raising concerns about the long-term consequences of such applications in urban and peri-urban agriculture, especially regarding children's exposure to Pb.
Contamination & food safetyOrganic cycleHealthOverview on urban and peri-urban agriculture: definition, impact on human health, constraints and policy issues
2008Erastus K. Kang’ethe, Delia Grace, Thomas F. Randolph · East African Medical Journal · East Africa
This study synthesizes current knowledge on urban agriculture (UA) in East Africa, focusing on its human health impact. It identifies UA as an important source of food security, but notes that many zoonotic and food-borne diseases are associated with it, with a lack of evidence on human health impact and management. Major constraints include illegality and limited access to inputs and markets, indicating a need for more research to understand both positive and negative health impacts.
Contamination & food safetyHealthFood sovereignty & justicePolicyEconomicsPeri-urban agricultureLinking research, capacity building, and policy dialogue in support of informal irrigation in urban West Africa
2008Pay Drechsel, Olufunke Cofie, R. van Veenhuizen, Theophilus O. Larbi · Irrigation and Drainage · West Africa
Informal irrigation in urban and peri-urban agriculture (UPA) in West Africa offers benefits but is often hindered by water pollution, threatening public health. A multi-stakeholder process implemented since 2005 in six West African cities, including Accra, Ghana, aimed to integrate UPA into sustainable urban development. However, an internal lesson learned was that local partners may not prioritize every project, and capacity-building efforts might not provide expected incentives for commitment.
Contamination & food safetyPolicyHealthPeri-urban agricultureCommunityVers un assainissement urbain durable en Afrique subsaharienne : approche innovante de planification de la gestion des boues de vidange
2006Halidou Koanda · Infoscience (Ecole Polytechnique Fédérale de Lausanne) · Sub-Saharan Africa
In Sub-Saharan Africa, faecal sludge management practices are often financially unviable due to widespread lack of municipal involvement, paucity of legal provisions, and absence of stakeholder coordination. This leads to indiscriminate dumping of faecal sludge in urban areas or its untreated use in urban agriculture. These practices pose permanent and serious health risks and contaminate scarce ground and surface water. This research aims to develop an innovative strategic planning approach for sustainable urban faecal sludge management to minimize public health and environmental risks.
Contamination & food safetyHealthOrganic cyclePolicyWater, land and health in urban and peri‐urban food production: the case of Kano, Nigeria
2003Tony Binns, Roy Maconachie, Adamu Idris Tanko · Land Degradation and Development · Nigeria (Kano)
This paper examines health and environmental concerns associated with urban and peri-urban agriculture (UPA) in Kano, Nigeria. Empirical evidence indicates that industrial and domestic toxins are reaching dangerously high levels, leading to significant pollution of soils and water channels. This raises serious questions about the sustainability of UPA and the long-term health implications of toxin exposure.
Contamination & food safetyHealthPeri-urban agriculturePolicyUrban agricultural production: heavy metal contamination of Amaranthus cruentus L. grown on domestic refuse landfill soils in Ibadan, Nigeria
2003Ogunyemi Awodoyin, Taliat Opadeji · Emirates Journal of Food and Agriculture · Nigeria (Ibadan)
A 2003 study in Ibadan, Nigeria, investigated heavy metal contamination of Amaranthus cruentus L. grown on domestic refuse landfill soils. Lead (Pb) and Cadmium (Cd) concentrations in soils from four landfill sites and a control site ranged from 110.5 to 678.5ppm for Pb and 2.01 to 3.20ppm for Cd. Metal accumulation in Amaranthus cruentus L. tissues was proportionate to soil Pb concentrations, while Cd levels in crop tissues exceeded soil levels. Crop growth and yield were significantly reduced due to Pb and Cd contamination, leading to the conclusion that Ibadan landfills are unsafe for Amaranthus cruentus cultivation, with heavy metal concentrations in the vegetable tissues much higher than FAO/WHO dietary allowances.
Contamination & food safetyHealthPeri-urban agriculture