Research & reports

Maëlle Tripon, Dorothée Boccanfuso, Marie-Ève Yergeau · Cahiers de recherche · Global

This literature review examines urban agriculture (UA) models, their implementation contexts, production needs, and impacts. It highlights that UA faces limitations, particularly restricted access to good quality (unpolluted) soil, water, and air, which can negatively impact productivity. UA can also have negative impacts on ecosystems and human health, such as pollution and diseases, depending on management methods.

Lauren Balotin, Samantha Distler, Antoinette L. Williams, Samuel J. W. Peters, Candis M. Hunter, Chris Theal, Gil Frank, Taranji Alvarado, Rosario Hernandez, Arthur Hines, Eri Saikawa · International Journal of Environmental Research and Public Health · United States (Atlanta)

This study investigated Atlanta residents' knowledge regarding heavy metal and metalloid (HMM) exposures and remediation in urban agriculture, following the detection of industrial slag and hazardous soil contamination in West Atlanta in 2018. Through surveys and follow-up interviews, it was found that participants were concerned about the potential health effects of soil contaminants but unconcerned with produce in their gardens. Gardeners' knowledge of HMM exposure sources and remediation methods was low and varied based on racial group.

Omanjana Goswami, Ashaki A. Rouff · Soil Systems · United States (Newark)

Soils from seven community farms in Newark, New Jersey, USA, were analyzed for lead (Pb) concentration and speciation. Single-step extractable Pb concentration ranged from 22 to 830 mg kg−1, with 21% of samples exceeding the NJDEP limit of 400 mg kg−1 for residential soils. Lowest Pb concentrations were detected in raised beds, while uncultivated native soil and parking lot samples had the highest values. Although most Pb is associated with reducible and oxidizable soil fractions, indicating a lower risk of mobility and bioavailability, Pb exposure through ingestion and inhalation pathways remains a concern when directly handling the soil.

Herman Parfait Awono-Ambene, Laurelle Djieukap Njieyap, Patrick Akono Ntonga, Josiane Etang, Christophe Antonio‐Nkondjio, Cyrille Ndo, Jacques Étamé, Flobert Njiokou, Serge Hubert Zébazé Togouet · Journal of Environmental Science and Public Health · Cameroon (Yaounde)

This study analyzed water and soil samples from three market garden sites in Yaounde, Cameroon, from October to December 2016, for physicochemical characteristics and parasite identification. The analysis of 82 samples revealed the presence of 3 protozoans (Entamoeba histolytica, Sarcocystis sp., and Giardia intestinalis) and 11 helminths in the soil. The presence of viable helminths suggests that harmful soil pathogens such as protozoans and helminths can spread through market gardening.

Милена Йорданова, Вера Петрова, Цветелина Николова, Елена Цветкова, Milena Yordanova, Vera Petrova, Tsvetelina Nikolova, Elena Tsvetkova · Bulgarian Portal for Open Science · Global

This article considered the potential risks of contamination in urban agricultural products. Urban agriculture, particularly in large cities, areas with heavy traffic, or near industrial zones, can lead to the accumulation of heavy metals in vegetable crops due to air pollution, traffic pollution, and other sources. Consuming these contaminated fresh vegetables is noted to potentially deteriorate human health.

Reuben Nwoye Okechi, Edna Ifeoma Chukwura, Christian Okechukwu Nweke · Journal of Advances in Microbiology · Nigeria (Owerri)

This study, conducted in Owerri, Nigeria from June to December 2019, evaluated the interactive toxic effects of ternary mixtures of sodium dodecyl sulfate (SDS) and divalent metals on Serratia marcescens (SerEW01) from the Otamiri River, a source for urban farming. The study found that both concentration addition (CA) and independent action (IA) models predicted lower toxicities compared to experimentally observed data. The Toxic Index and Model Deviation Ratio indicated a synergistic interaction of SDS and metal ions, resulting in higher combined toxicities than predicted, posing environmental hazards due to co-contamination.

H. Tayal Neeraj · · Global

This chapter explores the potential of home gardening, as part of urban agriculture, to contribute to human health through improved nutrition. While home gardens can provide nutrient-dense foods, the potential health impact of soil contamination must be addressed, as urbanized soils tend to have elevated levels of heavy metals and other toxins.

Mila Siti Fatimah, M.S Ir. Eko Hanudin, Ph. D. Toru Watanabe · · Vietnam

This study investigated heavy metal contamination in soils, vegetables, and irrigation water in peri-urban agricultural areas of Hue, Vietnam, from May 2018 to January 2019. Samples from three sites revealed that while irrigation water and agricultural soils were not seriously contaminated, 14% of vegetables were contaminated by Cr, 76% by Cd, and 47% by Pb. The consumption of vegetables was categorized as a tolerable health risk.

Moisés Savian, Mari Inês Caríssimi Boff, Pedro Boff · Cadernos de Agroecologia · Brazil

This study evaluated Brazilian scientific production from 2009 to 2018 on urban agriculture's contribution to food and nutritional security, analyzing 34 selected articles out of 612. It found that while agrobiodiversity is present in urban agriculture areas, pesticide use is a reality in some crop plots. The research suggests urban agriculture must be based on agroecology to avoid environmental contamination and produce healthy food.

Baptiste Grard, Nastaran Manouchehri, Christine Aubry, Nathalie Frascaria‐Lacoste, Claire Chenu · International Journal of Environmental Research and Public Health · Global

A five-year experimental trial quantified the food production potential, soil fertility, and potential contamination of Technosols created from urban wastes for rooftop edible production. The cropping system showed promising results for food production and maintained high fertility. However, a concern was identified regarding the trace metal content of certain edible crops, specifically zinc (Zn) and copper (Cu), although most trace metal levels were below existing norms.

Hillary A. Craddock, Elisabeth Fost Maring, Stephanie Grutzmacher · African Journal of Food Agriculture Nutrition and Development · Ethiopia

A mixed-methods pilot survey of 21 teachers and parents in Debre Berhan, Ethiopia, investigated household agricultural practices to understand foodborne illness risks. The study found that half of respondents using manure applied uncomposted manure as fertilizer, and many kept multiple animal species. This suggests a high risk of pathogen exposure for children and adults through contact with uncomposted manure and animals.

Joycelyn K. Quansah, Cesar L. Escalante, Angela Parry‐Hanson Kunadu, Firibu Kwesi Saalia, Jinru Chen · Agriculture · Ghana (Accra)

A survey was conducted among 102 urban leafy green vegetable farmers from 12 farming areas in Accra, Ghana, to determine agricultural practices and their association with microbial safety of vegetables produced. It was observed that 70% of farmers used water from waste drains for irrigation, 99% used incompletely composted manure, 96% harvested with bare hands, and over 60% disagreed that polluted irrigation water can contaminate vegetables or make consumers sick. Vegetables cultivated by farmers with no formal education, less food safety knowledge, and those who disagreed about contaminated water causing illness were associated with higher fecal coliform and Enterococcus sp. counts.

Salvatore Engel‐Di Mauro · Journal of Environmental Quality · Global

This review examines atmospheric sources of trace element (TE) contamination in cultivated urban areas (CUAs), noting that these sources are understudied and poorly understood despite extensive research on TE contamination in CUAs. Existing research often assesses atmospheric deposition indirectly or lacks controls for other TE contaminants, and shows little engagement with atmospheric sciences methodological guidelines, which reduces confidence in current findings. The review suggests combining atmospheric science techniques with existing robust methodologies for TE contamination studies in CUAs.

Silke Cram, Pilar Fernández, Horacio Carranza, M.C. Gómez Hernández, Claudia Ponce de León, Ana M. Noguez Gálvez · Open Journal of Soil Science · Global

This study evaluated metal inputs, transfer, and translocation in lettuce (Lactuca sativa L.) grown in an urban plot during dry and rainy seasons in 2013, using treated wastewater and rainwater respectively. While soil characteristics and metal transfer/translocation factors varied temporally, leading to different metal concentrations in lettuce tissues, the results indicated that the metal concentration in lettuce tissues posed no harm to human health. However, site-specific studies are necessary for urban agriculture management.

Remigio Paradelo, Antía Villada, María Teresa Barral · International Journal of Environmental Research and Public Health · Global

A two-month pot experiment studied heavy metal transference from five metal-rich urban waste composts and a manure vermicompost to lettuce and Italian ryegrass under controlled conditions. Plant concentrations of Zn, Cu, and Cd increased with their concentrations in compost, while no such relation was observed for Pb. The study found that the ratio of element concentration in plant to compost was much higher for Zn, Cd, and Cu than for Pb, indicating lower bioavailability of Pb.

Małgorzata Ćwieląg‐Drabek, Agata Piekut, Klaudia Gut, Mateusz Grabowski · Scientific Reports · Europe

A study of family allotment gardens (FAGs) in Silesia Province, one of the most polluted regions in Poland, analyzed 219 soil samples and 64 edible plant samples to link the geochemical disturbance caused by past mining and smelting activity to consumer exposure to toxic and carcinogenic metallic trace elements. Contents of these elements in topsoil were spatially diverse and depended primarily on the location of industrial pollution sources. Average cadmium (0.52 mg/kg fresh weight) and lead (0.57 mg/kg fresh weight) content in vegetables exceeded maximum permissible concentrations under European quality standards. A human health risk assessment based on three dietary exposure scenarios found that, in every scenario, potatoes — a staple of the Polish diet — carried the highest average daily dose for all three elements. The study concludes that consuming vegetables grown in Silesia Province's family allotment gardens may pose a significant health risk to consumers.

Georgette N. Ngweme, Dhafer Mohammed M. Al Salah, Amandine Laffite, Periyasamy Sivalingam, Dominique Grandjean, Konde Nkiama Numbi Joël, Crispin K. Mulaji, Florian Breider, John Poté · The Science of The Total Environment · Africa

This study investigated levels of persistent organic pollutants (POPs) in irrigation water, soil, and Amaranthus viridis from gardening sites in Kinshasa, Democratic Republic of the Congo, to assess environmental and human health risks. A survey of pesticide and fertilizer use was conducted with 740 market gardeners, and POPs (organochlorine pesticides, PCBs, PBDEs, and PAHs) were analyzed in irrigation water and 144 vegetable samples. The highest PAH levels were found in A. viridis at all sites studied; the sum of seven PCB congeners ranged from 15.89 to 401.36 ng/g; chlorpyrifos-ethyl and p,p'-DDE were the predominant OCPs detected; and among PBDEs, only BDE47 was quantified at notable concentration in the plants, with none detected in irrigation water. Higher estimated daily intake values indicated that consuming the leafy vegetables could be associated with increased health risks, though calculated incremental lifetime cancer risk values indicated no potential carcinogenic risk for the local population. The study recommends implementing urban agriculture control programs for POPs and fertilizer use in Kinshasa to protect public health.

Joseph Richmond Fianko, Mavis Korankye · West African Journal of Applied Ecology · Ghana

A study assessed the environmental and health impact of urban and peri-urban irrigated agriculture in Ghana by analyzing the physico-chemical and microbiological characteristics of irrigation water in the Greater Accra Region, calculating a comprehensive pollution index (CPI) and sodium adsorption ratio (SAR). Water samples used for informal irrigation contained significant microbial loads: total coliform ranged from 25×10² to 1209×10² cfu/100ml and E. coli from 2×10² to 651×10² cfu/100ml, with a mean total coliform level (517.917×10² cfu/100ml) far exceeding the recommended maximum guideline values of 5,000 and 1,000 cfu/100ml for irrigation water. CPI values ranged from 0.16 to 0.43 (average 0.27), indicating moderate pollution; about 42% of samples were classified as sodic waters, and SAR values of 3.42 to 24.75 meant nearly all samples exceeded the threshold (SAR > 4) associated with reduced water infiltration and soil permeability problems. The water is described as under persistent pollution pressure from expanding human activity, posing high risks to the health of the environment, farmers, traders, and consumers.

Anna Margenat, Víctor Matamoros, Sergi Dı́ez, Núria Cañameras, Jordi Comas, Josep M. Bayona · Environment International · Spain (Barcelona)

A study assessed 16 trace elements and 33 organic microcontaminants in lettuce, tomato, cauliflower, and broad beans from peri-urban farms near Barcelona, Spain, and a rural site. Concentrations ranged from non-detectable to 17.4 mg/kg for trace elements and non-detectable to 256 μg/kg for organic microcontaminants, with tomatoes showing the highest levels. Risk assessment indicated a low human health risk from consuming these vegetables in the peri-urban area, comparable to the rural site.

Pernille Malberg Dyg, Søren Christensen, Corissa Jade Peterson · Health Promotion International · Global

A thematic review of 51 articles published between 1980 and 2017 examined the effects of community gardens on wellbeing among vulnerable populations. Findings suggested positive impacts on physical health and individual/social wellbeing, but food security enhancements were inconsistent. Two articles raised potential food safety concerns in urban community gardens, recommending attention to minimizing these risks.

· Journal of Animal and Plant Sciences (J Anim Plant Sci ) ISSN 2071 – 7024 · Africa

A study in Port-Bouët, Abidjan, examined market gardeners' phytosanitary practices and pesticide residue incidence on lettuce. It found that 39.6% of pesticides used were not recommended for market gardening, 86.84% of gardeners did not protect themselves during application, and 80.26% did not observe pre-harvest intervals. Consequently, 93.33% of lettuce samples did not comply with Codex Alimentarius and EU standards due to high pesticide residue contamination.

Christine Aubry, Nastaran Manouchehri · OpenEdition (OpenEdition) · France (Paris)

Urban and peri-urban agriculture is exposed to various forms of pollution related to cultivation methods and urban air and soil quality, with different crop types exhibiting varied reactions to pollutants. The T4P and REFUGE programs on urban farms in the Paris region, and the ADURAA and QUALISANN programs studying vegetable-growing in Antananarivo, Madagascar, aim to assess health risks and oversee practices using methodological frameworks.

Cosmos C. Alamanjo, Abimbola O. Adepoju, H. Martin, R.N. Baines · Zenodo (CERN European Organization for Nuclear Research) · Nigeria (Jos)

This mixed-methods study investigated farmers' perceptions, willingness, and capacity to use household sewage sludge as organic resources for peri-urban agriculture around Jos, Nigeria. Farmers were found to use a complex mix of fertilizers and were keen to utilize household sewage sludge for soil fertility, though constrained by accessibility. A critical finding was that household sewage sludge observed in the field is heterogeneous due to its proximity to urban refuse disposal, raising concerns for possible cross-contamination of pollutants and indicating a lack of extension guidance.

Anna Paltseva, Zhongqi Cheng · RUDN Journal of Agronomy and Animal Industries · United States (New York City)

Elevated trace metal concentrations, particularly lead (Pb), are prevalent in New York City urban soils. This study analyzed the spatial distribution of lead in NYC gardens and assessed pollution levels and ecological risks. Findings indicated that lead posed moderate to significantly high ecological risk, and the majority of NYC garden soils were characterized as polluted.

Camille Dumat, Antoine Pierart, Muhammad Shahid, Sana Khalid · · Global

Urban agriculture, while a strategy for sustainable food production, faces a serious threat from natural and anthropogenic pollution sources in urban and peri-urban environments. These sources release hazardous organic and inorganic contaminants, leading to a high likelihood of human exposure. Consumption of vegetables grown on polluted urban soils or those that have intercepted metal-rich atmospheric particles represents a potential route of pollutant exposure and human health hazard.