Research & reports
Peer-reviewed research and reports on community urban agriculture, food education, composting, welfare and more.
Theme
Critical findings
6 results
Uncontrolled urban vegetable farming poses public health risks in Ethiopia
2025Taffere Addis, Sisay Ketema, Abayneh Melaku · Frontiers in Water · Ethiopia (Addis Ababa)
This study in Addis Ababa, Ethiopia, investigated trace metal levels in sediment, soil, and irrigated vegetables from farms along the Akaki River, evaluating public health risks. Sediment levels of arsenic, chromium, copper, nickel, lead, and zinc exceeded threshold effect levels. Soil levels of arsenic, chromium, copper, manganese, and zinc exceeded typical world soil values, with nickel at one site exceeding EEC limits for agricultural soils. Critically, arsenic, lead, and zinc levels in some vegetable samples were above WHO allowable limits, despite soil levels being acceptable, and cadmium was the most accumulated metal in vegetables.
Contamination & food safetyHealthUrban–rural linkageHeavy metal occurrence within urban agriculture practices in eastern zones of Nairobi city
2023Njenga John Ng’ang’a, Mukundi John Bosco, Masinde Peter Wasike, Kihurani Agnes Wanjiru · Journal of Agriculture Science and Technology · Kenya (Nairobi)
A study in Nairobi's eastern zone assessed heavy metal occurrence in urban farm inputs and food crops (tomatoes, arrowroots, kales). Cadmium, manganese, lead, and zinc concentrations were analyzed in soil, water, and crop samples. The study found that heavy metal contents, particularly cadmium, manganese, lead, and zinc, were above allowable limits in several crops, and based on FAO/WHO standards, were high for health concern.
Contamination & food safetyHealthUrban–rural linkageChromium Laden Soil, Water, and Vegetables nearby Tanning Industries: Speciation and Spatial Distribution
2021Adugnaw Maru Gezahegn, Fekadu Fufa, Esayas Alemayehu, Abebe Beyene · Journal of Chemistry · Ethiopia (Modjo city)
This study investigated the spatial distribution and speciation of chromium in water, soil, and edible plants in tannery-contaminated areas of Modjo city, Ethiopia. Total chromium in the Modjo River was 20.6 mg L−1 upstream, and soil Cr (III) and Cr (VI) concentrations were found to be higher than guideline values. Chromium concentrations in edible plants were also significantly higher than in control areas, with roots accumulating more chromium than leaves and fruits. It was concluded that water, soil, and edible plants in this area contain chromium concentrations higher than recommended for a healthy environment and human consumption.
Contamination & food safetyHealthUrban–rural linkageUrban farming as a possible source of trace metals in human diets
2016Joshua Oluwole Olowoyo, Gladness Nteboheng Lion · South African Journal of Science · South Africa
This review reports on the concentrations of trace metals in crops, including leafy vegetables, harvested from various urban areas. It highlights the presence of trace metals in leafy vegetables and discusses various pathways of uptake, possible health risks associated with urban farming, and morphological and physiological impacts of trace metals in leafy vegetables.
Contamination & food safetyHealthPeri-urban agricultureUrban–rural linkageMicrobiological and Physicochemical Evaluation of Jakara Canal Wastewater Used for Irrigation in Kano
2015M. G. Dahiru, Onaiwu Idahosa Enabulele · · Nigeria (Kano)
Microbiological and physicochemical parameters of urban wastewater from the Jakara Canal in Kano were analyzed to assess its potential for irrigation. Mean fecal coliform counts ranged from 64.43 ± 63.20 MPN 100/ml to 216.85 ± 350.16 MPN 100/ml, increasing along the canal. All physicochemical parameters were within FEPA and WHO/FAO acceptable limits, but conductivity needed monitoring to avoid salinity.
Contamination & food safetyHealthOrganic cycleUrban–rural linkagePollution 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 linkage