Research & reports

Isaiah Sewanu Akoteyon, Adeyemi Davidson Aromolaran · International Journal of Environment and Sustainable Development · Nigeria (Lagos)

This study evaluated peri-urban market gardening and shallow well water quality for irrigation in Lagos, Nigeria. It found that the mean values of bicarbonate, calcium, and pH in shallow wells exceeded detection levels in 66.7%, 60%, and 53.3% of samples, respectively. Salinity and sodium hazard patterns showed that approximately 66.7% of shallow wells had low salinity, 26.7% medium, and 6.7% high.

Robert Garey Stewart, Marcel Korth, Laurenz Langer, Shannon Rafferty, N Rebelo Da Silva · · Global

This paper is a protocol for a systematic review on the impacts of urban agriculture programs on food security and nutrition in low and middle-income countries. It notes potential disadvantages of urban agriculture, including contamination, spread of diseases, depletion of water supplies, soil erosion, and health risks from pesticides. The review aims to identify, appraise, and synthesize evidence on these impacts comprehensively and transparently, given that the existing evidence-base is not well understood.

Marcelo Ortega Romero, Juan Mingot Marcilla, María Jesús García Martínez, Eduardo de Miguel, Miguel Izquierdo‐Díaz, Amaya Gómez · · Spain (Madrid)

This study evaluated the potential health risk from trace elements in urban garden soils in Madrid, Spain. Thirty-six composite soil samples were collected from the top 20 cm of six urban gardens, and concentrations of cobalt, chromium, copper, nickel, lead, and zinc were determined. The findings indicated that urban soils are significantly enriched in trace elements relative to background levels, suggesting a potential health risk.

Mansur 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.

Prem José Vazhacharickal, Martina Předotová, D. Chandrasekharam, Sharit K. Bhowmik, Buerkert, Andreas · Journal of Agriculture and Rural Development in the Tropics and Subtropics (University of Kassel) · India (Mumbai)

A study surveyed 38 railway gardeners to characterize urban and peri-urban agricultural production along railway tracks in the Mumbai Metropolitan Region. Irrigation water contained nutrients but also heavy metals such as lead, cadmium, and mercury, and pathogens like Escherichia coli. Heavy metal levels exceeded critical thresholds in surface soils for chromium, nickel, and strontium, and in produce for lead, cadmium, and strontium.

Adam J Long · Scholarship @ Claremont (The Claremont Colleges) · United States (Washington, DC)

This study investigated heavy metal soil contaminants in 13 urban community gardens in Washington, DC, analyzing 45 soil samples using X-ray fluorescence (XRF). While most samples fell below US EPA action levels for common contaminants, high concentrations of lead (above the US EPA action level of 400 ppm) were found in the native soil of three garden sites, meriting concern due to potential health problems in children.

Kohei Makita, Eric M. Fèvre, Charles Waiswa, Mark Bronsvoort, Mark C. Eisler, Susan C. Welburn · Land Use Policy · Uganda

This paper describes a spatial representation of the peri-urban interface (PUI) of Kampala, Uganda, and identifies socio-economic factors related to peri-urbanicity using rapid rural mapping. It notes that urban and peri-urban agriculture (UPA) in rapidly expanding cities carries public health risks, such as zoonotic disease transmission. The study provides a methodology for describing the PUI in developing countries.

Sophie Graefe, Eva Schlecht, Andreas Buerkert · Outlook on Agriculture · Niger (Niamey)

Semi-structured interviews with 130 households in Niamey, Niger, characterized urban and peri-urban agriculture (UPA) and assessed resource use. The study found high use of livestock manure and indiscriminate use of nutrient-loaded wastewater for irrigation, leading to significant nutrient surpluses in UPA gardens. Initial calculations suggested large gaseous emissions of nitrogenous compounds and and leaching of nitrogen, phosphorus, and potassium to groundwater.

Erastus 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.

Seyed Esmaeil Mahdavian, R. Somashekar · ePrints@Bangalore University (Bangalore University) · India (Bangalore)

A study in Bangalore city, India, showed that urban consumers are at greater risk of purchasing fresh fruits with high levels of heavy metals beyond the legally permissible limits defined by the Indian Prevention of Food Adulteration Act, 1954. These national norms are less strict than international food safety standards.

Bernard Keraita, Pay Drechsel, Flemming Konradsen · Water Science & Technology · Ghana (Kumasi)

A study in Kumasi, Ghana, assessed the use of on-farm ponds to reduce microbial contamination in wastewater-contaminated irrigation water, analyzing over 300 samples. It found that while ponds are common, their potential for pathogen removal via sedimentation is not fully optimized. Helminth eggs reduced by about 70% with careful water collection, but thermotolerant coliforms took six days in the dry season to meet WHO guidelines, indicating suboptimal performance for some pathogens.