Research & reports

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.

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.

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.

Miguel Izquierdo‐Díaz, Peter E. Holm, Fernando Barrio‐Parra, Eduardo De Miguel, Jonas Duus Stevens Lekfeldt, Jakob Magid · Journal of Environmental Quality · Global

This study evaluated air pollution in urban green areas using edible plants. Analysis of 36 unwashed leaf samples showed that plants exposed next to roads had higher contents of traffic-related elements, and outdoor samples were enriched in marine aerosol ions. Cadmium and lead concentrations did not exceed European legal maximum levels for vegetables, indicating their consumption would be safe.

L.C. Obuseng · Botswana Journal of Agriculture and Applied Sciences · Botswana (Gaborone)

This review highlights the potential for heavy metal accumulation in soil and crops from urban and peri-urban agriculture (UPA) around Gaborone, Botswana, due to the intensive use of chemical fertilizers, pesticides, wastewater, sludges, and industrial effluents. A literature review showed that fertilizers contain heavy metals, and the use of treated or untreated sewage water by UPA farmers can lead to heavy metal accumulation in soil and crops, posing a danger to human health. Information on heavy metal accumulation in soils is limited in Botswana, despite high agrochemical use in UPA vegetable production.

Ariamys Companioni, Jennys Peraza, Zulema Menéndez Díaz, Aileen González, Ledy X López, Ana Elisa Rodriguez, Jorge Cantillo, Fidel Ángel Núñez · Dialnet (Universidad de la Rioja) · Cuba

A descriptive study in La Lisa Municipality, Havana, Cuba, examined 63 Rattus rattus rodents for Angiostrongylus cantonensis infection in an urban farm field. The study found that 46.03% of the captured rodents were infected with A. cantonensis, with infection rates increasing in adult individuals (59.46%) and during the rainy season (55.88%). This demonstrated the circulation of A. cantonensis in its definitive host in the area, indicating an increased risk of transmission to humans.

Surendra K. Pradhan, Olufunke Cofie, Josiane Nikiema, Helvi Heinonen‐Tanski · Sustainability · Global

This research determined the fertilizer value of sawdust and fecal sludge (SDFS) pellets and compared their effect on lettuce cultivation with other fertilizers in a greenhouse and open field. SDFS pellets, with or without enrichments, resulted in higher saleable fresh weight lettuce yields than commercial compost, poultry manure, mineral fertilizer, or no fertilizer. Open field cultivation yielded more than greenhouse cultivation. While no helminth eggs were detected, some fecal coliforms were found in lettuces fertilized with almost all tested fertilizers, including NPK and the non-fertilized control.

Honorine Ntangmo Tsafack, Émile Temgoua, Thomas Njiné · International Journal of Biological and Chemical Sciences · Cameroon

This in situ study in Dschang, West Cameroon, monitored the survival time of E. coli, parasite eggs, and cysts on lettuce, carrot, and eggplant irrigated with polluted urban wastewater for one week. Despite significant E. coli reductions (73-99% over seven days depending on crop and season), E. coli levels on lettuce and carrot remained above health thresholds (10^3 E. coli/g). Positive samples for eggs and cysts ranged from 0-25% on lettuce and carrot, and 0-8% on eggplant, posing a danger to consumers of raw vegetables.

Obinna Elijah Nworie, Junhao Qin, Chuxia Lin · Toxics · Global

This study investigated trace element uptake by wild herbaceous plants at a multiple trace element-contaminated site. It found significant variability in bioaccumulation and translocation factors among plant species, identifying some as hyperaccumulators for specific elements. The marked accumulation of trace elements in plant tissues suggests that the site may not be suitable for urban agricultural production.

Baby Shaharoona, Said Al‐Ismaily, Ahmed Al‐Mayahi, Nadhira Al-Harrasi, Ruqaiya Al-Kindi, Abdullah Al-Sulaimi, Hamad Al-Busaidi, Mohammed Al‐Abri · Heliyon · Global

A study in A'Seeb city, Oman, combined a sociological questionnaire survey of residents' perceptions with sampling of pathogenic bacteria, water-soluble metals, basic cations, salinity and texture in soil and groundwater near urban gardens and municipal waste disposal sites. Most surveyed residents were not paying attention to the negative consequences of their activities on soil and the environment. Heavy metal concentrations were significant at some contaminated sites though still below international standards, while fecal contaminants were reported in some garden, waste-site and groundwater samples, identifying human pathogens in risk group 2 including Klebsiella pneumoniae, Shigella spp. and E. coli.

Abdallah Zacharia, Wajihu Ahmada, Anne H. Outwater, Billy Ngasala, Rob Van Deun · The Scientific World JOURNAL · Tanzania

This cross-sectional study, conducted from February to August 2018, evaluated three waste stabilization ponds (WSPs) in the Morogoro, Mwanza and Iringa regions of Tanzania, where treated effluent is used for urban agricultural activities despite the disease-transmission risks posed by untreated or partially treated wastewater. Using APHA physicochemical methods, the modified Bailenger method and Ziehl-Neelsen staining for parasites, and membrane filtration for fecal coliforms (FC), analyzed with SPSS version 20, the study found helminth egg removal ranging from 80.8% to 100% and protozoan (oo)cyst removal from 98.8% to 99.9%, with the Mwanza WSP showing the highest FC reduction (3.8 log units per 100 mL). Both parasites and FCs in the effluents of the assessed WSPs were found at concentrations exceeding World Health Organization and Tanzania Bureau of Standards limits, except for helminths in the Morogoro WSP and FCs in the Mwanza WSP. FC counts correlated significantly with protozoa (p<0.01) and predicted protozoa occurrence well (p=0.011), with correlations also found among physicochemical parameters, parasites and FC bacteria. The study attributes the systems' inadequate performance to a lack of regular maintenance and/or operation beyond capacity, and concludes that FC indicators are a reasonable proxy for monitoring protozoa but not for helminths, which should be surveyed independently.

Dan Li, Chun Hong Wong, Mei Fang Seet, Nicole Kuan · Frontiers in Microbiology · Singapore

This study conducted, for the first time to the authors' knowledge, an investigation of Stenotrophomonas maltophilia -- an emerging opportunistic pathogen capable of causing high-mortality nosocomial infections in immunocompromised patients while also being ubiquitous in the environment -- on leafy green vegetables and in a hydroponic farming facility in Singapore. Eleven isolates were recovered from three vegetable types (sweet basil, kale, parsley) and the nutrient solution, with high population levels reached in vegetables under abused storage temperatures (over 8-log CFU/ml in basil juice after six days at 20°C) and on hydroponic facilities through biofilm formation (8 to 9-log CFU/well), and UV treatment (over 4-log reduction at 250 mJ/cm²) was identified as an effective measure to reduce contamination in nutrient solutions and facilities.

Sandeep Kumar, Lal Chand Malav, ICAR- National Bureau of Soil Survey & Land Use Planning, Nagpur, 440033, Maharashtra, Shiv Prasad, Sunita Yadav, Amrita Daripa, ICAR- National Bureau of Soil Survey & Land Use Planning, Nagpur, 440033, Maharashtra · Agropedology · Global

This review argues that rapid industrialization and mechanization are driving heavy metal pollution worldwide, with both anthropogenic and natural sources of heavy metals reaching soil, water bodies and plants and ultimately entering the human body through the food chain. Heavy metals accumulate in plants and living organisms after uptake from soil and cause harm, and they are also toxic to soil biological activity by disrupting key microbial processes. The review states that, due to industrial development in urban areas, heavy metal contamination — from metals such as zinc, copper, lead and cadmium — has become a serious threat to the peri-urban agriculture that supplies vegetable production, and it surveys sources of contamination and remediation techniques, with a particular focus on phytoremediation.

Mohamad Assad, Michel Chalot, Fabienne Tatin‐Froux, Valérie Bert, Julien Parelle · Journal of Environmental Quality · Global

This study investigated element transfer in edible crops (cucumber, pepper, cabbage, lettuce) and poplar (Skado cultivar) grown on soils contaminated with sediments dredged from water canals in the 1960s, aiming to develop a biomonitor. The results showed accumulation of cadmium (Cd) and zinc (Zn) in the edible parts of crops, particularly leafy vegetables, indicating that Cd could be ingested in amounts reaching the tolerable daily intake (TDI) in this context. No accumulation of lead (Pb) was detected.

P.S. Bouda, Edmond Hien, A. Dioma, Hyacinthe Kambiré, Yacouba Maïga, Der Adolphe Somé, Sylvie Nazaret, A.S. Ouattara · DOAJ (DOAJ: Directory of Open Access Journals) · Burkina Faso

A study in Ouagadougou sub-urban agricultural fields, Burkina Faso, assessed the impact of using untreated Solid Urban Wastes (SUW) as agricultural fertilizers on soil properties and crop production. SUW amendment significantly increased pH, total C, N, P, and available P, and maize height and biomass yield were 124% and 164% higher in amended plots, respectively. However, trace metal elements (Cu, Zn, Pb, Ni, Cr) concentrations were higher in amended fields, indicating that urban waste carries contaminants posing public health risks.

Zane Vincēviča–Gaile, William Hogland, Māra Stapkēviča, Juris Burlakovs · Linnaeus Eco-Tech · Latvia

This study investigates the transfer of metallic elements in the soil-plant segment of the food chain through laboratory and field experiments. It also includes a quantitative analysis of food samples from Latvia, including fruits and vegetables from Riga city allotment gardens, to identify element composition and potential contamination risks from urban pollution. Results of experiments and analyses revealed the influence of factors such as seasonality, botanical origin, site-specific factors, agricultural practice, and food processing on element transfer.

John Misenheimer, Clay Nelson, Evelyn Huertas, Myriam Medina-Vera, Alex Prevatte, Karen D. Bradham · Geosciences · Puerto Rico

Total and bioaccessible arsenic (As) and lead (Pb) levels, and their uptake by 10 commonly grown garden plants, were examined in three urban community gardens in Puerto Rico. Total As ranged from 2 to 55 mg/kg and Pb from 19 to 172 mg/kg in soils. Leaves accumulated higher concentrations of As and Pb than edible flesh, with culantro leaves showing the highest concentrations (3.2 mg/kg dw As, 8.9 mg/kg dw Pb).

Muhammad Shahid, Camille Dumat, Nabeel Khan Niazi, Sana Khalid, Natasha Natasha · VertigO · Global

Arsenic concentrations exceeding the World Health Organization's recommended limit (10 μg/L) have been frequently found in groundwater in several countries globally, exposing millions to arsenic. This study synthesizes recent interdisciplinary knowledge on arsenic, particularly for urban gardeners and farmers who may face contamination in well water or produced vegetables. Geogenic arsenic poses a major health threat in many countries, especially in Asia, and advice is proposed to avoid and reduce human exposure to arsenic in urban agriculture contexts.

Simon Kojo Appiah, Eric Nimako Aidoo, Derrick Asamoah Owusu, M. W. Nuonabuor · Zenodo (CERN European Organization for Nuclear Research) · Ghana (Kumasi)

This paper assesses the spatial distribution of heavy metals and potential ingestion risks in Kumasi, Ghana, using geostatistical techniques on topsoil samples. Results from univariate and multivariate semivariogram models showed strong spatial dependence with autocorrelations ranging from 100 to 300 meters. The produced risk maps indicate strong spatial heterogeneity for most soil heavy metals, with extremely high contamination risk found near commercial areas.

Tiantian Xiong, Camille Dumat, V. Dappe, Hervé Vezin, Eva Schreck, Muhammad Shahid, Antoine Pierart, S. Sobanska · Environmental Science & Technology · Global

This study assessed the phytotoxicity of copper oxide nanoparticles (CuO-NPs) in lettuce and cabbage, exposing them via leaves for up to 15 days to various CuO-NP concentrations. High foliar Cu uptake occurred, leading to decreased plant weight, net photosynthesis, water content, and necrotic Cu-rich areas. The findings highlighted a potential health risk associated with consuming vegetables contaminated with CuO-NPs.

Blaise Pascal Bougnom, Laura J. V. Piddock · Environmental Science & Technology · Global

This global perspective highlights the significant role of wastewater in urban agriculture as a factor in the dissemination of antibiotic resistance. Approximately 50-90% of antibiotics are excreted and end up in water ecosystems, particularly in low and middle-income countries with high antibiotic consumption. The aquatic environment acts as a reservoir and channel for the spread of clinically relevant antibiotic resistance traits.

Milan Geršl · · Czech Republic (Brno)

A study in Brno, Czech Republic, assessed toxic metal levels and soil attributes (pH, ORP, conductivity) in specific allotment garden areas using XRF analysis. Four out of eight metals (Cd, Cu, V, and Zn) exceeded legal norms, with cadmium (Cd) being the most hazardous at 12.69 mg/kg against a legal norm of 0.5 mg/kg. Despite high levels, the mobility of these metals was expected to be low given the detected soil attributes.

Muhammad Asif Khan Rai Muhammad Amir · International Journal of Biosciences (IJB) · Pakistan (Faisalabad)

To investigate heavy metal residue levels in cauliflower grown in the peri-urban area of Faisalabad district, Pakistan, 30 cauliflower samples were collected from 10 selected farmers. Analysis revealed variable heavy metal residue levels (nickel, lead, zinc, copper, arsenic, and mercury) in the samples, indicating that the cauliflower was contaminated with multiple heavy metals. This contamination is attributed to the use of untreated sewage water for cultivation, which is the single largest contributor to heavy metal accumulation in cauliflower.

Maud Chalmandrier, Marine Canavèse, Yves Petit‐Berghem, Élisabeth Rémy · HAL (Le Centre pour la Communication Scientifique Directe) · Global

This study, using case studies of public action and gardeners' relationships with urban soil, argues that the concept of "urban agriculture" smooths over inherent tensions to promote its development as an action category. This approach tends to minimize differences in meaning among actors regarding their cultivation practices and, critically, relegates the crucial question of urban soil quality and its suitability for food crops to a secondary concern.

이윤숙 · · Global

Urban agriculture has gained emphasis due to its importance for leisure and recreation in modern society. However, public health may not be guaranteed due to continuous odors from animal compost. Biochar is an amendment that can reduce odors and enhance crop productivity, but this abstract is truncated and does not present specific research findings.