Research & reports

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.

K.G. Rosin, Ravinder Kaur, Sushma Singh, Prabhat Kumar Singh, Digvijay Dubey · Procedia Environmental Sciences · India

A study was conducted in peri-urban agricultural sites around Faridabad, Haryana, India, to assess groundwater contamination and the contribution of salt/trace metal-laden irrigation waters. Mean EC, Cl, and F concentrations in root zone leachates were found to be far beyond permissible limits, and some trace metals posed a threat to deep percolating waters. However, due to existing cropping patterns and deeper water table depths, the groundwaters were not yet vulnerable to these salts/trace metals, and the presence of salts in the groundwaters was primarily geogenic.

Giovanni Attili · IRIS Research product catalog (Sapienza University of Rome) · Italy (Rome)

This study focused on community gardens in Rome, Italy, which largely result from informal appropriation practices. While these gardens can enhance environmental and social quality of life, they require institutional support and present a crucial challenge for urban planning. The study highlights the need to explore tensions between social practices and institutional powers, and questions how public policy can legitimize these self-guiding societal expressions.

Laura Knapp, Jodi L. Sangster, Shannon L. Bartelt‐Hunt · International Journal for Service Learning in Engineering Humanitarian Engineering and Social Entrepreneurship · United States (Omaha NE)

This study investigated the influence of lead hyperaccumulating plants on lead uptake by vegetables in an urban community garden in Omaha, NE, a region with significant lead contamination. Tomatoes, carrots, and amaranth were grown alongside sunflowers and mustard greens (hyperaccumulators) in lead-contaminated soil. Data showed higher lead concentrations in the hyperaccumulators and suggested that their presence might have impacted the amount of lead available to surrounding vegetation. Previous work at the garden detected lead in produce, indicating a potential exposure pathway for humans.

Kyle Kessler, Seth Umbenhauer, Alison R. Noble · Journal of the Pennsylvania Academy of Science · United States (Harrisburg)

Eight soil samples were collected from an urban land plot in Harrisburg, PA, to determine concentrations of copper, nickel, zinc, and lead and assess suitability for an urban garden. While copper, nickel, and zinc concentrations were below EPA recommended limits, lead concentrations ranged from 26 ± 1 mg/kg to 402+ mg/kg, with some samples exceeding EPA standards for heavy metals in home and vegetable gardens. This indicates potential lead contamination in the soil.

Melvin Delgado · Columbia University Press eBooks · United States

This chapter focuses on community gardening as an intervention aimed at addressing obesity, tracing its history in the United States back to the late nineteenth century as a response to social and economic crises. While community gardens can achieve various social, economic, political, educational, and health-related goals, the chapter also discusses potential pitfalls of community gardening. It emphasizes a social justice perspective for community gardens, particularly regarding community inclusion and participatory democracy.

Chris Zimmerman · Soil Horizons · United States

A narrative article profiling the work of soil scientist Samantha Langley-Turnbaugh of the University of Southern Maine, investigating lead contamination in urban soils in Portland, Maine. It traces the concern to the Great Fire of 1866, whose lead paint ash was spread across the city and used as landfill to extend the Portland peninsula, compounded by the city's historical ties to lead-producing industries. The article states that, across US cities generally, lead paint and leaded gasoline are the primary sources of soil lead contamination, and that this contamination is becoming a concern as urban gardening expands.

Ines Vlahović, Ksenija Karlović · Agronomski glasnik ·

A survey conducted from May to August 2011 examined the frequency of poisonous and allergenic plant species at nine educational institutions in the town of Samobor, Croatia — three kindergartens, four elementary schools, one high school and one library. The survey identified 15 poisonous plant species, represented by 182 specimens, and 17 allergenic plant species, represented by 129 specimens.

David DyckFehderau, Nicholas L. Holt, Geoff D.C. Ball, Noreen D. Willows · PubMed · Canada

A study in Alexander First Nation, central Alberta, Canada, used asset mapping with children to understand how community factors shape the lifestyle behaviors of First Nations children living on reserve, who are estimated to be 4.5 times more likely to be obese than Canadian children generally. Participants were a convenience sample of two high school students working at the local health centre and seven grade six children, who used maps, photographs and a town tour to identify 25 activity- or food-related places and spaces. Breakfast, lunch and snack foods (such as chocolate bars and potato crisps) were obtained at school, food and snacks at cultural gatherings, and snacks at the local store, with healthy food choices found to be limited; only two locations beyond the town site were identified for physical activity, and youth recommended building a leisure centre, selling healthier food at the local store, and developing a community garden and berry farm.

Evaristo Mwaba Kapungwe · Open Journal of Metal · Africa

Water, soil, and crop samples were analyzed by atomic absorption spectrometry for lead, copper, cobalt, nickel, and chromium at two peri-urban wastewater-irrigation farming sites in Zambia: New Farm Extension in Mufulira Town, Copperbelt Province, and Chilumba Gardens in Kafue Town, Lusaka Province. Heavy metal levels in wastewater, soil, and food crops exceeded acceptable limits at both sites, confirming contamination and a potential human health risk from consuming the crops grown there.

Ruth Stewart, Marcel Korth, Laurenz Langer, Shannon Rafferty, Natalie Rebelo Da Silva, Carina van Rooyen · Environmental Evidence · Global

This is a systematic review protocol — not a completed review — that sets out methods for identifying, appraising and synthesizing evidence on how urban agriculture programs affect food security and nutrition in low- and middle-income countries. It notes urban agriculture is widely promoted as providing the urban poor with food and income while improving the urban environment, but also carries potential disadvantages: use of wastewater can contaminate produce, intensive irrigation can spread malaria and water-borne disease and strain limited water supplies, and soil erosion and intensive fertilizer/pesticide use can pose health risks and environmental damage. Despite the current policy drive to promote urban agriculture, the paper states that the evidence base for its benefits and harms is not well understood. As a protocol, it reports planned search, screening, bias-appraisal and synthesis methods rather than results.

Léon W. Nitièma, Boubacar Savadogo, Dramane Zongo, Aminata Kaboré, Poda Jean Noël, Alfred S. Traoré, Dayéri Dianou · Journal of Environmental Protection · Africa

This study examined the microbial quality of wastewater used for truck farming in Ouagadougou, Burkina Faso, testing for bacterial and parasitological fecal indicators during the dry-hot season (May) and the wet season (July) of 2012. Wastewater from three water reservoirs and two canals intensively used for truck farming was analyzed, and the same indicators were tracked through waste stabilization ponds at three treatment plants in the city. Concentrations of microbial indicators were significantly higher in the dry-hot season than the wet season across all sampling sites, with levels reaching up to 53,800 CFU/100ml for E. coli, 8,200-108,400 CFU/100ml for fecal coliforms, 650-45,000 CFU/100ml for fecal streptococcus, and 0-2.4 eggs/l for helminths. Through the waste stabilization ponds, significant microbial concentration drops of 82-100%, 78-98%, 60-100%, and 82-88% respectively were recorded between the anaerobic and maturation ponds. The results indicate that improving the refining performance of waste stabilization pond technology could help reduce the health risks associated with wastewater reuse in urban agriculture in developing countries.

G. 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.

Ghulam Murtaza, Abdul Ghafoor, Muhammad Zia‐ur‐Rehman, Muḥammad Ṣābir, Asif Naeem · Communications in Soil Science and Plant Analysis · Global

This study investigated metal accumulation in plants grown in urban agricultural lands irrigated with untreated city effluent in developing countries. Sewage samples showed hazardous electrical conductivities, sodium adsorption ratios, and residual sodium carbonate for irrigation, although metal levels were near permissible limits. Critically, plants acquired metal contents that were greater than those found in the raw sewage or soils, indicating significant metal uptake.

Nahed N. Mahrous · The Journal of Pediatrics · Canada (Hamilton)

This project investigated metal, bacteria, and corn root interactions in metal-contaminated soils from Blackfrairs Community Garden and a Hamilton home. It found that bacterial numbers were lower than in uncontaminated soils, and bioavailable metal concentrations increased over time. High concentrations of metals were detected in grains, with copper, iron, and manganese accumulating in rhizospheres, and zinc distributed throughout root tissue in Blackfrairs plants.

I. Karabozhilova, Barbara Wieland, Silvia Alonso, Laura Salonen, Barbara Häsler · British Poultry Science · United Kingdom (London)

A 2010 questionnaire survey of 30 backyard chicken flock-keepers in the Greater London Urban Area found that while chickens generally had conditions for natural behaviors, most owners did not comply with regulations on catering waste feeding. Disease prevention measures were rare, and a lack of avian and zoonotic disease knowledge among owners was observed, indicating implications for disease control.

Julie L. Self, Amanda Wyatt, Aimee Webb Girard · The FASEB Journal · United States (Atlanta)

This research characterized community gardens (CGs) in two urban counties in Atlanta, Georgia, through semi-structured interviews with diverse garden leaders. The study identified primary barriers to creating and sustaining CGs as leadership constraints, reliable access to natural resources, and unclear regulations. It also found that CGs foster access to fresh food, knowledge, and community connections, with benefits varying by community.

Lori Leonard, W. J. S. Mwegoha, Charles Kihampa · International Journal of Plant Animal and Environmental Sciences · Tanzania (Dar es Salaam)

This study investigated public awareness and health risks from heavy metal pollution in vegetables irrigated with Msimbazi River water in Dar es Salaam, Tanzania. Over 71% of 35 respondents used the river for irrigation, and high levels of chromium, lead, and copper were detected in popular vegetables. 69% of respondents were unaware of industrial pollution, and 63% were unaware of potential health effects. The study found that 95.6% of adults, 30.7% of children aged 6-12, and 12.5% of children aged 2-6 were at risk of lead carcinogenic effects, while 5% of children aged 2-6, 2.8% of children aged 6-12, and 1.2% of adults were at risk from carcinogenic cadmium effects.

Jenny Calabio, Ma. Luisa Albacete · WVSU Research Journal · Philippines (Iloilo City)

This study, conducted from July 2007 to July 2008 at the Urban Agriculture Demonstration Site in La Paz, Iloilo City, evaluated soil media and ameliorants for container-grown green onion, pechay, and tomato. Pure compost was found to be the best medium for increasing yields. However, the use of IMO and rice hull as soil ameliorants did not increase yields for the three tested vegetables, and rice hull generally reduced pechay yields.

Aubin Ondo, Pascale Prudent, C. Massiani, Menye Biyogo, Mariane Domeizel, Jacques Rabier, François Eba · Journal of the Serbian Chemical Society · Gabon (Libreville)

An assessment of urban agriculture's impact on soil properties and metal uptake by leafy vegetables in Libreville, Gabon, found strong soil acidification and decreased nutrient/metal concentrations due to agricultural practices. Metal transfer to plants was significant, with amaranth accumulating more metals than other vegetables, though cadmium and lead were not detectable in plant tissues. Amaranth and roselle preferentially concentrated metals in their leaves.

Zbigniew Ziembik, Agnieszka Dołhańczuk-Śródka, Grzegorz Kusza · Proceedings of ECOpole · Poland

Soil samples were collected from the former "Piast" cement plant within Opole city borders, Poland, and nearby allotment gardens to study radioisotope activity concentrations. Naturally occurring radioisotopes and artificial Cs were found, with K and Cs showing the biggest radioactivity concentration. No significant differences in radionuclide activities were found between soil samples from the former industrial estate and the allotment gardens.

Johanna F. Lindahl · · Vietnam

The circulation of Japanese encephalitis virus (JEV) in pigs and mosquitoes was investigated around Can Tho city in Vietnam's Mekong Delta. Of 315 sows, 60% were JEV seropositive, and seropositivity was associated with more stillborn piglets in sows under 1.5 years old. Among 7885 mosquitoes collected in and around Can Tho city, seven pools collected near pigs tested positive for JEV, indicating co-circulation of JEV genotypes I and III. All 43 pigs sampled within Can Tho city were JEV seropositive, demonstrating that JEV can be a public health issue in urban areas.

Evaristo Mwaba Kapungwe · Indonesian Journal of Biotechnology (Universitas Gadjah Mada) · Zambia

This study investigated farming practices related to heavy metal contaminated wastewater irrigated farming in two peri-urban areas of Zambia: New Farm in Mufulira and Chilumba Gardens in Kafue. Data was collected by observing crop cultivation activities at field plots along transects in stratified land zones. The results revealed that farming practices were characterized by traditional land management and multiple cropping systems, influenced by agro-ecological factors and the availability of heavy metal contaminated wastewater, which has the potential to contaminate soils and crops.

Jennifer E. Reeves · OhioLink ETD Center (Ohio Library and Information Network) · United States (Cleveland, Ohio)

This two-year study in Cleveland, Ohio, USA, investigated urban soil health via nematode food web analysis and crop productivity via tomato fruit yield in urban gardens. Market gardens showed significantly more soil organic matter, nitrogen pools, and nematode presence than community gardens in both 2011 and 2012. However, despite these differences, there was no significant difference in the total yield of tomatoes per square meter between market and community garden types in either year. Gardens with raised beds had significantly more soil moisture content and soil organic matter than those with flat beds.

W. H. Butler · Journal of Agriculture Food Systems and Community Development · United States

The reintroduction of livestock into urban areas in the United States creates tensions regarding public health and the urban-rural divide. This paper analyzes municipal codes to identify how communities regulate urban livestock through prohibitions of certain animals, zoning, site-level restrictions, and management requirements. The analysis demonstrates that while no two municipalities approach the urban livestock question identically, each seeks to place limits on raising livestock in urban areas using a combination of regulatory land use tools.