Research & reports

R. Holm Thomas · Lincoln (University of Nebraska) · United States (Lincoln)

This study investigated remediation strategies to reduce heavy metal uptake in soil from a potential community garden lot near a railroad in Lincoln, NE, where elevated concentrations of lead (Pb) and arsenic (As) were detected. In a greenhouse experiment, romaine lettuce was grown. Biochar amendment resulted in the lowest concentrations of Pb and As in lettuce leaves and stems, whereas coffee grounds amendment led to the highest concentrations across all tested plant parts.

Tanmoy Roy Tusher, Md. Eusuf Sarker, Sumaya Nasrin, Tapos Kormoker, Ram Proshad, Md. Saiful Islam, Shamim Al Mamun, A. R. M. Tareq · Toxin Reviews · Bangladesh

This study investigated toxic metal and PAH contamination in rooftop soils and vegetables (red amaranth, spinach) in urban and peri-urban Bangladesh. Urban rooftop soil and vegetables were highly contaminated with toxic metals and PAHs compared to peri-urban samples. Lead (Pb) and cadmium (Cd) concentrations in urban vegetables exceeded safe limits. However, health risk indices indicated that the levels of toxic metals and PAHs in urban rooftop vegetables would not pose carcinogenic or non-carcinogenic health risks for adults and children, deeming them safe for consumption.

Fabien Ilunga Mpanga, Michel Shengo Lutandula⃰ · The Global Environmental Engineers · Democratic Republic of Congo (Lubumbashi)

A study conducted in the Kasungami district of Lubumbashi, Democratic Republic of Congo, investigated the link between the use of polluted waters in urban agriculture and heavy metal contamination in soil and cultivated vegetables (amaranths, broccolis). Physicochemical and mineral analyses of water, soil, and plant samples revealed that heavy metals, except cobalt, were present in the water used for urban agriculture at concentrations below quality standards, but the soil contained heavy metals at phytotoxic concentrations. Only broccolis were contaminated with lead, while amaranths had heavy metals below quality standards. These findings suggest that urban agriculture in large agglomerations of the DRC could endanger consumers' health.

Gábor Teke, Katalin Hubai, Dorina Diósi, Nóra Kováts · Bulletin of Environmental Contamination and Toxicology · Global

This laboratory study assessed the foliar uptake and accumulation of airborne polyaromatic hydrocarbons (PAHs) in lettuce (Lactuca sativa) using an aqueous extract of urban aerosol, following OECD Guideline 227. The study found significant accumulation of PAHs in lettuce, with naphthalene showing the highest bioconcentration factors (BCFs) and anthracene, pyrene, and fluoranthene showing the lowest bioaccumulation potential. The BCF of each PAH strongly correlated with its molecular weight.

Cleusa Fernandes Ramos, Andréia Assunção Soares, Isabela Carvalho dos Santos, F. Ramos, Odair Alberton, Luciana Kazue Otutumi, Lidiane Nunes Barbosa, Ricardo de Melo Germano, Daniela Dib Gonçalves, Luiz Sérgio Merlini · Journal of Pure and Applied Microbiology · Brazil

This 2020 study in Brazil evaluated the bacteriological quality of six medicinal plants from community gardens, including Cymbopogon citratus and Aloysia citriodora. Analysis of cold extracts revealed bacterial contamination, with Plectranthus barbalus showing the highest aerobic mesophile count and Aloysia citriodora the highest coliform count at 45°C. However, the study concluded that heat treatment (boiling for teas) can significantly reduce or eliminate this bacteriological contamination, making the plants safe for consumption.

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 Chenarides, Carola Grebitus, Jayson L. Lusk, Iryna Printezis · Agribusiness · United States

This study examined household-level participation in urban agriculture (community and home growing) before (2017) and during (2020 lockdown) the COVID-19 pandemic in Phoenix, AZ, and Detroit, MI, using two online surveys and bivariate probit models. It found that considerably fewer individuals participated in community gardens compared to home gardening, and overall participation was lower in 2020 than in 2017. The continuity of individuals' participation in growing food at community gardens and home is fragile, and many urban households' food-growing practices may not yet be mainstream, suggesting other barriers inhibit participation.

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.

Christine Lux, Brianna Routh, Lacy Stephens · Journal of Human Sciences and Extension · United States

This exploratory study surveyed 21 parents from a campus-based preschool in the northwest United States during the 2017-2018 school year to understand the impact of the "Harvest of the Month" program on children's nutrition behavior at home. Findings indicated that a variety of program foods were served and consumed at home, but parents prioritized knowing food origins over serving local foods. Parents' knowledge of farm to ECE, reported farmer's market purchases, and CSA participation were limited, suggesting a need for targeted parent education.

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.

Miho Lowan‐Trudeau, Noel Keough, Joshua Wong, Sara Haidey · Canadian Geographies / Géographies canadiennes · Canada (Calgary)

This study, examining community gardens in Calgary, aimed to determine the socio-economic demographics of neighborhoods supporting community gardens and their proximity to active transportation and public transit. GIS visualization and quantitative analyses were used to investigate relationships between demographic variables and transportation accessibility. Findings showed that community garden neighborhoods are located in areas with significantly fewer visible minorities, higher levels of educational attainment, and more attached dwellings like apartments and townhomes. This study suggests potential inequities in the proliferation of public community gardens based on socio-economic factors beyond economic capital.

Carrie Ann Benjamin · Sociální studia / Social Studies · France (Paris)

This study examines community gardening and participatory urbanism in Paris, focusing on the Goutte Verte, a temporary nomadic community garden. The continued existence of the Goutte Verte is in opposition to the city's much-needed housing, with gardeners caught between a desire for green space and a demand for comfortable housing. Community gardens are shown to act as a material alternative to urban planning and governance that often fail to account for a "place to breathe" in the city.

Katie L. Butterfield, A. Susana Ramírez · Health Education & Behavior · United States (Minnesota)

A quantitative content analysis was conducted on descriptions, missions, and goals provided by 411 community garden managers across Minnesota. Six frames were consistently present, including "greater good" and "community orientation," which were the most common. The findings suggest that the prevalent "greater good" frame may inadvertently reproduce inequality by alienating food-insecure populations, similar to other alternative food programs.

Selda Cansu TEMEL · GRID - Architecture Planning and Design Journal · Turkey

This study analyzed the planning and design criteria of public primary school gardens in Üsküdar district, Istanbul, Turkey, to determine their proficiency levels against national, international, and academic standards. Using quantitative and qualitative methods, including on-site observation, the research identified architectural disadvantages and inadequacies in the school gardens. The findings indicate deficiencies in the current state of these outdoor recreation areas.

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.

Silvana Nicola, A. Ferrante, Giacomo Cocetta, Roberta Bulgari, Carlo Nicoletto, Paolo Sambo, Andrea Ertani · Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Horticulture · Global

The Covid-19 pandemic revealed the vulnerability of the agrifood system, with lockdowns disrupting long-distance fresh vegetable supply chains and causing dramatic declines in local market sales. While purchases concentrated in supermarkets, increasing crowding risks, gardening can increase opportunities for local and fresh food availability. Scaling up local food production is important to enhance community resilience.

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.

Kate Gardner Burt, Gail Mayer, Rachel Paul · Local Environment · Global

A systematic review analyzed 277 community gardening articles to assess outcomes of community garden participation related to food justice, synthesizing 31 studies. Many positive impacts were indicated across seven social and dietary outcomes. Community garden participation was positively correlated with community connectedness, but evidence demonstrating diet improvement was neutral. Methodological rigor in study design and lack of participant racial/ethnic and socioeconomic diversity were common issues, leaving the effectiveness of community gardening as a strategy for a more equitable food system unclear.

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.

Govinda Prasad Devkota, Sheri Lee Bastien, Petter D. Jenssen, Manoj K. Pandey, Bhimsen Devkota, Shyam Krishna Maharjan · International Education Studies · Nepal

This Participatory Action Research study in Nepal investigated five teachers' perceptions of using urine diversion dry toilets (UDDTs) and human urine as fertilizer in school gardens. Few teachers accepted human urine as fertilizer, considering it impure and expressing unwillingness to use it on crops. Teachers disliked UDDTs due to perceived bad odor and uncomfortable sitting positions, especially for females, and felt urine as fertilizer was unnecessary.

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.

Gülşah KURU, Esra DEMİR ÖZTÜRK, Furkan Atmaca · İlköğretim Online · Global

A study using semi-structured interviews with 30 primary school teachers and 12 school managers revealed opinions on the evaluation of primary school gardens. The majority of participants believed their school gardens were inadequate, citing examples such as a lack of playgrounds, insufficient green areas, and the use of gardens as car parks.

Pepijn Schreinemachers, Ray-Yu Yang, Dhruba Raj Bhattarai, Bal Bdr, Mamounata Sandaogo Ouedraogo · · Global

Three cluster randomized controlled trials in Bhutan, Nepal, and Burkina Faso evaluated school garden programs. The interventions significantly improved children's knowledge about food and agriculture in all three countries, and awareness and preferences for fruits and vegetables in Bhutan and Nepal. However, these improvements did not lead to an increase in the frequency or variety of fruit and vegetable consumption in any of the countries.