Research & reports

Nur Dinie Syahirah Sanusi, Fadhlina Che Ros, Siti Zulaikha Ngah Demon, Ismayadi Ismail, Imad Hamadneh · Journal of Advanced Research Design · Malaysia

This mini-review discusses the extensive use of AB mix nutrients in Malaysian urban farming, noting their role in high yields but also their contribution to significant environmental pollution when overused. Although a survey of local entrepreneurs showed most complied with guidelines for chili plants, intensive use of fertilizers leads to nutrient leaching into the soil, causing environmental pollution and affecting humans, livestock, and microbial life. The review emphasizes the need for controlled nutrient application to prevent soil degradation and groundwater contamination.

Muhammad Waqas, Kamran Ashraf, Muhammad Mohiuddin, Asim Abbasi, Khawar Sultan, Muhammad Umar, Hayssam M. Ali, M. Abdel-Hamid, Qamar Zaman · Notulae Botanicae Horti Agrobotanici Cluj-Napoca · Global

This study assessed heavy metal and metalloid concentrations in ridge gourd, soil, and irrigation water, finding that groundwater samples exceeded permissible limits for Ni, Fe, Cu, Pb, As, Cr, and Cd. Soil irrigated with groundwater showed Cd, Cr, and As above limits, and ridge gourd samples had higher Cd levels than safe limits. Consumption of ridge gourd from the studied area may pose health hazards due to elevated target hazard quotients for Zn, Fe, and Cr, and high cancer risks from Ni, Cr, Cd, As, and moderate risk from Pb in canal water.

Wendy J. Heiger-Bernays, Alicia Fraser, Valerie Burns, Kerry Diskin, Diedre Pierotti, Kian Merchant-Borna, Michael D. McClean, Daniel J. Brabander, H. Patricia Hynes · Scholarworks (University of Massachusetts Amherst) · United States (Boston)

This study identified the nature and extent of soil contamination by polycyclic aromatic hydrocarbons (PAHs) from railroad ties and arsenic from chromated copper arsenate (CCA) pressure-treated lumber in a representative community garden in Boston. Elevated levels of PAHs and arsenic were present in the gardens studied, with these timbers serving as a continuous source of contaminants. This is the first study to investigate contaminants other than lead and evaluate the effect of adding city compost on select soil contaminants in urban garden soil.

Fernanda Olivares, John Clunes, Susana Valle, Dorota Dec · Agro Sur · Chile (Valdivia)

This study evaluated the quality of irrigation water in urban gardens in Valdivia, Chile, against Chilean standards NCh 1333 and NCh 409. Measured parameters included pH, electrical conductivity, total dissolved solids, and iron concentration. All urban gardens met the established standards, with the exception of the Collico garden, which showed an elevated iron concentration.

Ivonne Alonso Durán, Elizabeth Hernández-Álvarez, Ofelia Mortón-Bermea, Javier Castro-Larragoitia, Margarita Collazo-Ortega · Revista Internacional de Contaminación Ambiental · Mexico (Mexico City)

This study investigated the concentrations of 15 metal(loid)s in four vegetables (tomato, onion, chili, lettuce) cultivated in four urban garden locations in Mexico City. While soil analysis showed only vanadium exceeded Mexican limits in one location, various vegetables harvested in the study exceeded international recommended limits for cadmium, mercury, and lead. Lettuce exhibited the highest metal concentrations and transfer factors, with exceptionally high transfer factors for cadmium in lettuce and mercury in tomato.

Nilanjana Ganguli, Anna Maria Subic, Janani Maheswaran, Byomkesh Talukder · Global Health Journal · Global

A systematic literature review of 55 papers identified five distinct planetary health risks associated with urban agriculture, despite its environmental benefits. The study highlighted particular concerns regarding trace metal bioaccumulation in soil and vegetables, posing health risks to populations. Additionally, risks related to wastewater irrigation, backyard livestock farming, and gaps in infectious disease research were identified.

Roberta Bulgari, Erdona Demiraj, Calogero Schillaci, Ahlem Tlili, Yushu Xia · Urban Agriculture & Regional Food Systems · Global

This special issue examines urban and peri-urban soil and plant management, highlighting that soil-related factors in urban agricultural systems pose unique challenges. Issues such as soil fertility, soil biodiversity, and soil contamination require further investigation to enhance urban agriculture's contribution to livability. The issue collects studies supporting sustainable soil management and crop diversification, and explores remote sensing and deep learning for soil health monitoring and plant disease detection related to contamination.

Sabina Rossini Oliva, Rafael López Núñez · Environmental Science and Pollution Research · Spain (Andalusia)

This study evaluated potentially toxic elements (PTEs) in vegetables and topsoils from urban gardens in Seville, Cordoba, Huelva, and a mining area (Riotinto), Spain, comparing them with market and peri-urban samples. Soils in the mining area and cities generally showed higher contamination with As, Cr, Cu, Pb, and Zn compared to other locations. Despite this, all PTE concentrations in vegetables from the studied urban gardens, including those from As-contaminated soils, were below health-based guidance values and market levels (except lettuce), and human health risk assessments indicated safe consumption.

Fatimata Bintou Josiane Diarra, Isidore Juste O. Bonkoungou, Zakaria Garba, Namwin Siourimè Somda, Djifahamaï Soma, Marguerite Edith Malatala Nikiema, Évariste Bako, Souleymane Sore, Natéwindé Sawadogo, Nicolas Barro, Kaisa Haukka · Microorganisms · Burkina Faso (Ouagadougou)

A study in Ouagadougou, Burkina Faso, assessed the occurrence of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-Ec) and Klebsiella spp. (ESBL-K) in 356 samples from lettuce, the environment, and gardeners' stools in market gardens. The overall prevalence of ESBL-producing bacteria was 65.2%. Specifically, ESBL-Ec was found in 25.0% of lettuce samples and ESBL-K in 43.4% of lettuce samples, indicating a high prevalence of these resistant bacteria in urban agriculture.

Stefania Lovo, Samantha Rawlings · The World Bank Economic Review · Ghana, Nigeria

This study investigated the impact of e-waste dumping sites on neonatal and infant mortality, focusing on two major dumpsites in Ghana and Nigeria. Using a difference-in-differences approach, outcomes were compared for children born near and far from dumpsites before and after their creation. E-waste sites increased neonatal and and infant mortality for those living closer to the sites, with event studies suggesting effects emerge two to three years after site openings. There is suggestive evidence that contamination of water and of urban farming produce are among the drivers of the observed effects.

Hailekiros Tadesse Tekle, Desta Berhe Sbhatu, Gebreselema Gebreyohannes · H2Open Journal · Ethiopia (Mekelle)

A study in Hadnet district, Mekelle, Ethiopia, assessed heavy metal concentrations in wastewater, spring water, and three leafy vegetables (lettuce, spinach, cauliflower). Wastewater samples from four experimental sites exceeded permissible limits for 4 out of 10 heavy metals (Cd, Cr, Cu, Mn), and spring water from a comparison site also exceeded limits for 4 metals (Al, As, Cd, Cu). Leafy vegetables grown in the least contaminated experimental site showed high concentrations for 6-7 out of 10 heavy metals, with lettuce and spinach having elevated levels of As and Al, respectively. The study concluded that the wastewater used for irrigation is not safe, the farm soils may have accumulated significant heavy metals, and the cultivated vegetables are highly contaminated, necessitating regulation of wastewater use for irrigation.

Prince Owusu Adoma, Afia Sakyiwaa Amponsah, Kwarteng Twumasi Ankrah, Francis Acquah, Hubert Amu, Richard Osei Agjei, Ruby Hanson · Environmental Health Insights · Ghana

This study in Kumasi, Ghana, assessed heavy metal concentrations in lettuce and spring onion cultivated at anthropogenic urban sites. It found that mean concentrations of nickel in lettuce (137.15 ± 0.0231 mg/kg) and spring onion (173.55 ± 0.02 mg/kg) at BSGS, and zinc in both vegetables across most sites, exceeded WHO/FAO permissible levels. Furthermore, the cancer risk factor for nickel in both lettuce and spring onion exceeded the benchmark of 1 × 10−6, indicating a potential increased cancer risk for consumers from long-term consumption.

Luke Beesley, Michael Hardman · Cities · Global

This opinion piece discusses the potential risks of urban agriculture (UA) practices within Green Social Prescribing (GSP), particularly in post-industrial regions. It highlights barriers related to heavy metal-enriched urban soils, emphasizing the need for greater awareness and management of these risks. The piece provides recommendations for improving knowledge exchange on urban soils and risk in GSP contexts.

Almou Abdoulaye Alio, Alio Sanda Abdel-Kader, Alio Fody Mahamadou, Chaibou Yaou, Rabiou Mamane Moustapha, Hamidou Djelifa, SOUMANA SOUROUNDA Idé, Mahamane Idi Issa Abdoulahi, Lewamy Mamadou, Haoua Sabo Seini, Hassimi Sadou · Asian Journal of Biology · Niger (Niamey)

This study assessed the impact of irrigation water on the bacteriological quality of lettuce in three market garden sites in Niamey, Niger. Analysis of 18 lettuce and 29 irrigation water samples revealed high contamination across all sites with various bacteria, including total coliforms, fecal coliforms, enterobacteria, and E. coli. The irrigation water quality was found unsuitable for irrigation, significantly contaminating the lettuce and posing potential health risks to consumers.

Elliot Buckminster, Charlotte Breckenridge, Thomas Sedgwick · International Journal of Research in Agronomy · United Kingdom

This research quantified soil-to-plant transfer factors for six heavy metals (Cd, Pb, Zn, Cu, Ni, Cr) in lettuce, spinach, and carrot across 20 peri-urban agricultural sites in Berkshire, UK, from 2021-2022. Cadmium exhibited the highest mean transfer factor (0.31), and at 4 of 20 sites, cadmium concentrations in lettuce exceeded the EU maximum limit of 0.20 mg/kg fresh weight. Soil pH was a strong predictor for Cd and Zn transfer factors, with TFs increasing below pH 6.0.

Cosimo Dondini, Xavier Úbeda, Giacomo Certini, Marcos Francos · Journal of Soils and Sediments · Spain (Barcelona)

This study analyzed soils from ten urban gardens in Barcelona, Spain, with a special focus on possible contaminants. Irrigation water was also analyzed, and some of the waters contained a high concentration of salts and nitrites, which are listed as a pollutant. While three tests for heavy metals did not attest to significant pollution, other toxic elements not considered in this study could come from road transport gases or the port of Barcelona. Overall, the soil quality was concluded to be suitable for growing vegetables.

Lee D. Bryant, Roy Maconachie, Bastian Schnabel, Abubakarr Swaray, Howard Gigi, Solomon Gbanie, Kabba Haroun Bangura, Anthony Kamara, Prince Antwi-Agyei · Water Science & Technology Water Supply · Sierra Leone (Freetown)

This paper examined the environmental health status of three urban and peri-urban agriculture (UPA) sites in Freetown, Sierra Leone. Qualitative and quantitative data revealed heavy metal concentrations significantly exceeding regulatory limits in sweet potato leaves and arable soil. Additionally, soaring levels of faecal coliform bacteria were found in irrigation water, and crops were identified as hyperaccumulators for environmental contaminants.

Jinrong Tong, Dongsheng Feng, Xia Wang, Min Wang, Mei-Lian Chen, Yanfen Chen, Yingqing Ma, Bo Mei, R. Chen, Mengfeng Gao, Siwen Shen, Hongkang Wang, Weiyi Zhang · Heliyon · China (Shanghai)

A study investigated pesticide residues and dietary intake risk in 7028 vegetable samples grown under modern urban agriculture in Shanghai from 2018 to 2021, analyzing 68 types of pesticides. Pesticide residues were detected in 29.21% of samples, with 0.47% exceeding China's national maximum residue limits (MRLs). The target hazard quotient (THQ) and hazard index (HI) for detected pesticides were all less than 1, suggesting there may be no obvious health hazard for residents.

Nyayu Khodijah, Ratna Santi, Riwan Kusmiadi, Ivan Rismunandar · Jurnal Agritech · Global

This research investigated the effect of nutrient type and lead (Pb) absorption on water spinach growth in a Kratky hydroponic system over 30 days. Plants were exposed to PbSO4 concentrations of 50, 100, 150, and 200 mg/L, with standard hydroponic (ABmix) and alternative nutrients. The study found that nutrient type significantly affected most growth parameters, with ABmix performing better than alternative nutrients. Crucially, no growth disturbance was observed due to PbSO4 contamination, and the combination of Pb concentration and nutrient type did not significantly affect growth or production, except for the number of leaves.

ke Chinelo Gloria, Eze H.C, Obasi C.J, Euphemia Afoma Ikegwuonu, Okonkwo Ngozi Nonyelum · International Journal of Research Publication and Reviews · Nigeria

To evaluate the water quality of the Obibia River in Amawbia, Anambra State, Nigeria, water samples were collected monthly and assessed for bacteriological and physicochemical parameters. The study identified multiple bacterial isolates, including Escherichia coli, Klebsiella pneumoniae, Salmonella enterica serovar Typhi, and Vibrio cholerae. Notably, E. coli, S. Typhi, and V. cholerae were frequently observed in both rainy and dry seasons. These findings suggest the necessity of adequate treatment before use and periodic evaluation of the water's quality for drinking and urban agricultural purposes.

Simone Trimmel, Stefan Wagner, Laura Feiner, M. Feiner, Daniela Haluza, Rebecca Hood‐Nowotny, Ulrike Pitha, Thomas Prohaska, Markus Puschenreiter, Philipp Spörl, Andrea Watzinger, Elisabeth Ziss, Johanna Irrgeher · Environmental Science and Pollution Research · Europe

A study of urban gardens in Vienna, Austria, building on a previous study of eleven gardens in the city that found elevated lead (Pb) levels in some soil and plant samples. This work examined the elemental composition of soil and plants from two of the affected gardens one year after compost amendment. ICP-MS analysis of tomato fruit skin, pulp and seeds showed only minor variations in elemental composition unlikely to affect food safety, whereas radishes showed a tendency toward contaminant accumulation in root tips and leaves. Washing lettuce significantly reduced levels of potentially toxic elements including Be, Al, V, Ni, Ga and Tl, underscoring the importance of washing garden produce before consumption; compost amendment was associated with reduced Zn, Cd and Pb levels in radish bulbs. Lead isotope ratios in soil and spinach leaf samples from the earlier study, assessed by MC-ICP-MS, showed a direct linkage between the Pb isotopic signatures in soil and spinach leaves, supporting their use as tracers of Pb sources in the environment.

Anne-Kristin Løes, Sebastian Eiter, Tatiana Rittl · Environmental Sciences Europe · Europe

Using soil data from ten peri-urban case farms near Oslo and Bergen, Norway, this study estimated how quickly potentially toxic element (PTE) concentrations would rise in soil under intensive application of compost or digestate from food waste, composted garden waste, or horse and poultry manure applied annually to meet a theoretical carrot crop's nitrogen, phosphorus and potassium demand. Under this intensive fertilization scenario, Norwegian soil quality limits for PTEs would be reached within 20-85 years, faster in soils with more organic matter, with limits reached first for copper and zinc, both essential micronutrients. The urban waste-based fertilizers were also found to be poorly balanced in macronutrients, with rates covering potassium demand leading to high phosphorus and nitrogen surpluses. The study concludes Norway's PTE regulations are stricter than the EU's and do not support recycling organic matter and nutrients from urban waste.

Annamaria Gentile, Luca Di Stasio, Gianmaria Oliva, Giovanni Vigliottá, Angela Cicatelli, Francesco Guarino, Werther Guidi Nissim, Massimo Labra, Stefano Castiglione · Environmental Research · Global

A review examines the dynamics of antibiotic resistance (AR) in urban soils, cataloguing multiple sources that introduce antibiotics into urban soil, including domestic wastewater, industrial effluent and urban agricultural practices, as well as microplastics and domestic animal excrement. It states that the selective pressure from these anthropogenic sources promotes the proliferation of antibiotic-resistant bacteria through horizontal gene transfer among soil microorganisms, poses a significant public health threat by potentially transferring resistance genes to human pathogens via direct contact, food consumption and water ingestion, and disrupts microbial community dynamics in ways that affect soil fertility, plant growth and overall environmental quality.

Gamal El Afandi, Hossam Ismael, Souleymane Fall · Sustainability · United States

Using a hybrid approach combining the HYSPLIT and AgDRIFT models, this study estimated organophosphate pesticide spray drift from corn and soybean fields into urban-agricultural interface communities in Sangamon County, Illinois, at both field and county scales. Preliminary findings indicate that all residential areas near agricultural land are at risk of pesticide drift, since buffer zones do not exceed 25 meters; of 34 water bodies (rivers, lakes, streams, and drains) within the 30,200-acre study region, 12 fall within the high-drift zone, and roughly 106 buildings across an estimated 10,300 km² were found to have potential exposure to drift.

Elżbieta Skorbiłowicz, Piotr Ofman, Mirosław Skorbiłowicz, Marcin Sidoruk, Urszula Tarasiuk · Water · Poland

This study assessed heavy metal contamination in 96 surface sediment samples collected from urban, agricultural, and forested areas of the Bug River catchment in Poland between July 2018 and 2020, measuring metals (Zn, Pb, Cr, Ni, Cu, Fe, Mn, Cd) by atomic absorption spectroscopy and applying the geoaccumulation index (Igeo), contamination factor (CF), and pollution load index (PLI). Urban sediments showed significantly higher heavy metal concentrations than agricultural or forested areas, with cadmium reaching up to 2.5 mg/kg; the average Igeo for cadmium was 0.24 in agricultural areas and 0.15 in urban areas, while the highest PLI values, reaching a maximum of 0.33, occurred in urban areas, and statistical analysis showed both urban emissions and agricultural activities significantly influenced heavy metal presence in the sediments.