Research & reports

Barbara Matthys, Andres B. Tschannen, Norbert T. Tian‐Bi, Hermann Comoé, Salia Diabaté, Mahamadou Traoré, Penelope Vounatsou, Giovanna Raso, Laura Gosoniu, Marcel Tanner, Guéladio Cissé, Eliézer K. N’Goran, Jürg Utzinger · Tropical Medicine & International Health · Côte d'Ivoire

A cross-sectional survey was conducted in urban farming communities in Man, western Côte d'Ivoire, involving 113 farming households (586 individuals) and 21 non-farming households (130 individuals). The prevalences of S. mansoni and hookworm in farming households were 51.4% and 24.7%, respectively. Risk factors for S. mansoni included close proximity to the Kô River, water contact with irrigation wells and ponds, and low education attainment, while risk factors for hookworm included living in smallholder irrigated rice plots or large rice perimeters, using domestic well water, and low socioeconomic status.

Bernard Keraita, Flemming Konradsen, Pay Drechsel, Robert Clement Abaidoo · Tropical Medicine & International Health · Ghana

The effectiveness of low-cost irrigation methods (drip irrigation kits, furrow irrigation, and watering cans) in reducing contamination of lettuce irrigated with untreated wastewater in urban farming in Ghana was assessed. Analysis of 396 lettuce, 72 soil, 15 poultry manure, and 32 water samples revealed that lettuce irrigated with drip irrigation kits had the lowest contamination levels, with an average of 4 log units per 100g fewer thermotolerant coliforms than those irrigated with watering cans. However, drip kits often clogged, required lower crop densities, and restricted other routine farm activities.

F Ortega Sastriques, Rosa Orellana Gallego · Revista ciencias técnicas agropecuarias · Global

In many cities, potable water is expensive, and its availability is limited and will decrease in the future. Urban agriculture is an aspect to consider in this context.

F Ortega Sastriques, Rosa Orellana Gallego · · Global

Due to high prices and limited availability of drinking water in many cities, urban agriculture will require the use of alternative water sources. Groundwater and surface currents near cities are typically polluted, and this paper points out aspects to consider for safe irrigation using sewage water.

Stephanie Buechler, Gayathri Devi Mekala, B. Keraita · Victoria University Research Repository (Victoria University) · Global

This 2006 global study from Victoria University discusses wastewater use in urban and peri-urban agriculture for crop production and aquaculture, noting its role in generating livelihoods and providing cheap produce. However, the study emphasizes that clear policy guidelines and careful research are needed to prevent potential negative impacts on human health and the environment from wastewater reuse.

Jonathan Kingsley, Mardie Townsend · Urban Policy and Research · Australia (Melbourne)

A small qualitative study of members of the 'Dig In' community garden in Melbourne, Australia, explored the social capital benefits of urban community gardens. The study found that garden membership offers benefits such as increased social cohesion, social support, and social connections. However, these benefits do not necessarily extend beyond the garden setting, especially in the early stages of development.

Barbara Matthys, Penelope Vounatsou, Giovanna Raso, Andres B. Tschannen, EMMANUEL GBEDE BECKET, Laura Gosoniu, Guéladio Cissé, Marcel Tanner, ELIÉZER K. N’GORAN, Jürg Utzinger · American Journal of Tropical Medicine and Hygiene · Côte d'Ivoire

This study investigated malaria risk factors in urban farming communities in a medium-sized town in Côte d'Ivoire, conducting two cross-sectional surveys among 112 households across six agricultural zones. The overall prevalence of Plasmodium falciparum was 32.1%. Findings indicate that specific crop systems and agricultural practices may increase the risk of malaria in urban settings of tropical Africa.

Kigumure Buhindwa · Zenodo (CERN European Organization for Nuclear Research) · Rwanda (Kigali)

This study investigated malaria prevention activities in Kigali community gardens, Rwanda, through Community Health Volunteers (CHVs). A mixed-method approach, combining qualitative interviews and quantitative surveys, collected data on CHV activities and health outcomes. CHVs conducted weekly health screenings, reaching approximately 80% of the targeted population, and malaria prevalence dropped by 25% after six months. However, challenges included limited resources and inadequate training for CHVs, indicating that sustained support and additional training are necessary for long-term impact.

Astrid Mendez, Paulo Cseri Ricardo, P Jeny Pérez, Callejas Hernández, Osvaldo Campos · DOAJ (DOAJ: Directory of Open Access Journals) · Cuba

This introductory study in Arroyo Naranjo municipality, Cuba, examined the use of Luyanó effluent wastewater for irrigation in urban agriculture. The wastewater was classified as low contamination based on BOD5 and COD values and posed no toxic contamination risk to soil or environment. However, it should not be used without prior treatment for direct consumption crops due to its microbial load. Experimental plots with carrot, radish, and marigold showed high agricultural yields, and radish harvests had no bacterial contamination.

Halidou 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.

Juliana Arruda, Nilson Antonio Modesto Arraes · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) · Brazil (Campinas)

A 2005 study in Campinas, Brazil, analyzed the city's Community Garden Program (PHC) to support the formulation of new urban and peri-urban agriculture policies. Analysis of PHC management revealed an almost total disengagement between the program and sectoral policies such as education, health, and social action. However, individual actions were found to be important for project implementation and success, and the projects were significant in the lives of beneficiaries.

C. Paul Nathanail, Caroline McCaffrey, Naomi Earl, Neil D. Foster, A. G. Gillett, Richard Ogden · Human and Ecological Risk Assessment An International Journal · United Kingdom

This paper describes a deterministic method for deriving Site-Specific Assessment Criteria (SSAC) in the UK for human health risks from chronic exposure to heavy metals, metalloids, and organic substances in soil. The SSAC indicates soil concentrations above which unacceptable health risks may occur, considering standard and non-standard land uses and various exposure pathways. The method is not intended to generate or replace UK Soil Guideline Values, as this is the responsibility of UK authoritative bodies.

Nkawkaw Afriyie, Kofi Adziri, Yaw Asare, Amoako Gyamfi · Zenodo (CERN European Organization for Nuclear Research) · Ghana

A thematic analysis synthesized existing studies on community gardening impact measurement in Accra, Ghana, focusing on methodologies. While varied methods were reported, a notable theme emerged regarding the mixed results and challenges in accurately gauging the impact of community gardening on urban food security indicators, such as vegetable consumption rates among participants. This review underscores the importance of empirical data for understanding the effectiveness of urban agricultural interventions, but highlights methodological inconsistencies.

Samantha Langley-Turnbaugh, David E. Wilkinson, D. Rocque · Soil Survey Horizons · United States

This study characterized urban soils in a low-income neighborhood of Portland, Maine, that was heavily industrialized in the late 1800s, examining seven pedons for particle size, cation exchange capacity (CEC), base saturation, exchangeable bases, pH, and trace elements (Pb, Cr, Cu, Co, Cd, Ni, Zn, Hg, Ti, Zr). The soils contained numerous artifacts and showed a high degree of horizontal and vertical spatial variability; several trace elements were present at elevated levels, with lead (Pb) the dominant metal in surface horizons (600 mg/kg), and many metals correlated with each other and with iron and aluminum, and some with clay content and pH, though the study concludes that mapping soil units by specific trace element ranges would be difficult given the extreme variability observed.

Tanja Pless‐Mulloli, Vivienne S. Air, Catherine Vizard, Ian Singleton, D. L. Rimmer, Philip Hartley · Epidemiology · United Kingdom

A study in an urban, industrial allotment site in the UK's northeast assessed the potential for public health impact related to soil contamination by taking 86 soil samples and analyzing vegetables and eggs. All 18 initial soil samples exceeded UK guidelines for lead (median 869 mg/kg) and arsenic (median 40 mg/kg), and widespread contamination with PCDD/F was also found. Despite high soil contamination, the uptake of lead and arsenic into vegetables and eggs was low, and these were not deemed major exposure pathways.

R. B. Singh · IAHS-AISH publication · India

A study on wastewater management in 300 class-I cities and 23 metropolitan cities in India found that the total wastewater generated is approximately 158x10^8 l/day, with treatment capacity being only 375x10^7 l/day. In metropolitan cities, only 30% of wastewater is treated before disposal, and most cities only have primary treatment facilities. Untreated water is being used for urban agriculture, posing risks to public health and potential surface and groundwater pollution.

Martin Krauß, J. Moering, Walther Amelung · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · Global

This study aimed to assess whether local soil contamination contributes to PCB contamination in apples (Malus domestica Borkh.) at an allotment garden site, in addition to background atmospheric deposition. The importance of the soil-air-plant pathway for persistent organic pollutants like PCBs has been rarely studied, and it is unknown if volatilization from contaminated soils or deposition of contaminated soil dust is a significant source compared to background deposition. The research sought to clarify this potential contamination route for apples.

Prebus, Olivia · Occidental College Scholar (Occidental College) · United States (Los Angeles)

This work addresses the gross inequity of food access in low-income neighborhoods of Los Angeles, such as MacArthur Park, where grocery stores are scarce. The author's internship at the Center for Food and Justice involved projects like a Community Food Assessment and organizing a community garden, all focused on empowering communities to tackle complex food access issues. The abstract highlights the severe problem of limited healthy food options leading to simultaneous obesity and malnutrition.

F.P. Huibers, O. Moscoso, Álvaro Ocampo Durán, J.B. van Lier · CABI Publishing eBooks · Bolivia

A study examining wastewater use in urban and peri-urban agriculture in Cochabamba, Bolivia. Both vegetable and fodder crops are irrigated with polluted water — diluted or partly treated municipal and industrial sewage — containing high concentrations of pathogens, heavy metals, and salts. In the downstream La Mayca area, where farmers have an agreement with the municipal water and sewerage company, soil degradation has forced them to increasingly replace vegetable crops with more salt-tolerant fodder crops. In other areas around the city, cultivators deny using wastewater and point to nearby wells as their water source, but many of these wells are likely also polluted and do not yield enough water for the irrigated area they serve. Farmers report no specific health problems related to using polluted water, which contradicts reports from local health workers. Because surface water flow and rainfall are low while industrial pollution is high and wastewater treatment capacity is limited, most of the water available to farmers is of poor quality. Options identified for improvement include reducing industrial pollution, increasing treatment capacity, and adopting integrated water management that blends good-quality groundwater with wastewater — but strong traditional water rights, lack of urban planning, and weak institutions are cited as constraints on improving wastewater management in Cochabamba.

Olufunke Cofie, R. van Veenhuizen, Pay Drechsel · · Sub-Saharan Africa

Urban and peri-urban agriculture (UPA) significantly contributes to food supply, employment, livelihoods, and poverty alleviation in many Sub-Saharan African cities, providing diverse foods including perishable items. However, UPA production often carries health risks from polluted urban water and faces challenges due to limited semi-official recognition and support from city authorities, sometimes conflicting with planners regarding land tenure and water use. More data is needed for appropriate recognition of this sector.

Tony 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.

Ogunyemi 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.

Tanja Pless‐Mulloli, Karen L. Foster, J Bush · Epidemiology · United Kingdom (Newcastle upon Tyne)

Investigations in Newcastle upon Tyne, UK, analyzed the extent and consequences of disposing 2000 tons of incinerator ash on over forty allotments. Soil, egg, and vegetable samples (75 soil, 21 egg, 65 vegetable) revealed contamination of footpaths with dioxin/furan (max 9000 ng/kg I-TEQ) and high levels of copper, lead, and zinc. Mean dioxin/furan levels in soil were 38 ng/kg I-TEQ and in eggs were 16.4 ng/kg I-TEQ, indicating significant contamination and potential exposure pathways for allotment gardeners and children.

G. B. Luilo, Othman C. Othman · Journal de Physique IV (Proceedings) · Tanzania (Dar es Salaam)

This study measured heavy metal levels (cadmium, manganese, lead, and zinc) in Cynodon grasses near roads in Dar es Salaam City, Tanzania. Mean levels of lead and zinc varied exponentially with distance from the road up to 15m and correlated with average daily traffic, suggesting vehicular sources. For public health reasons, it is recommended that pasture grasses in road vicinities not be used for foraging dairy cattle and goats.

Bernard Keraita, Pay Drechsel, Philip Amoah · Environment and Urbanization · Ghana (Kumasi)

This study in Kumasi, Ghana, investigated the influence of urban wastewater on stream water quality and peri-urban agriculture through interviews and water quality assessments. It found that population increase and underinvestment in sanitation facilities led to large volumes of untreated wastewater entering streams. High levels of faecal coliform were recorded in the city's streams, downstream areas, and on vegetables sold in Kumasi’s markets due to contaminated wastewater.