Research & reports

Adnan Sirage Ali · Discover Public Health · Ethiopia

A comparative cross-sectional study of 315 urban vegetable-farming households along the Akaki Rivers in Ethiopia used structured questionnaires, multivariable logistic regression, multilevel mixed-effects models and bootstrapped mediation analysis. Two-week diarrhea prevalence was 11.4% (36/315) among children and 8.7% among adults; in this cross-sectional design, which cannot establish causality, wastewater irrigation was associated with more than double the odds of diarrhea (AOR=2.10, 95% CI 1.30-3.40), frequent contact with irrigation water with 80% higher odds (AOR=1.80), and regular raw-vegetable consumption with 60% higher odds (AOR=1.60). Handwashing with soap (57% risk reduction), bathing after farm work (41% reduction) and household water treatment (45% reduction, AOR=0.55) were protective, clustering by irrigation site was modest (ICC about 6%), and hygiene practices mediated 28% of the exposure-outcome relationship.

Mohssen Elbagory, Hassan M. El-Zahaby, EL-Shafeey E. I. EL-Shafeey, Nagwa EL-Khateeb, Alaa El-Dein Omara, Sahar El-Nahrawy, Amal Zayed, Pankaj Kumar, Jogendra Singh · Scientific Reports · India

A field-based comparative study in Saharanpur district, Uttar Pradesh, India, compared soil properties, the growth response of Indian mustard (Brassica juncea L. Czern.), and tissue accumulation of cadmium, chromium, copper, iron, manganese and zinc under irrigation with paper mill effluent (PME) versus borewell water as a control. PME irrigation significantly raised soil pH (8.79), electrical conductivity (4.73 dS/cm), organic matter (3.94%) and all six heavy metals (p<0.001); vegetative growth increased, but heavy metal accumulation was pronounced in roots, with bioaccumulation factors for iron and manganese exceeding the hyperaccumulation threshold and root enrichment factors reaching 226.50 for copper and 40.51 for chromium. Dietary risk modeling found that the health risk index from chromium in leaves exceeded the safety threshold in children (HRI=1.05) and approached risk levels for cadmium and chromium in adults, whereas the borewell-irrigated control soil remained within safe agricultural ranges, marking a clear contrast with the contaminated PME-irrigated soil.

Nwanaforo E., Obasi C. N., Akande I. O., Nduka J. K., Offor C. C., Abdulai P. M., Udom G. J., Orisakwe O. E. · Biological Trace Element Research · ナイジェリア（オウェリ・アバ・ポートハーコート）

A study of lead, cadmium and copper in urban agricultural systems in three industrial-area Nigerian cities (Owerri, Aba and Port Harcourt), assessing spatial distribution, bioaccumulation and health risks using both deterministic and stochastic (Monte Carlo) approaches. Atomic absorption spectrophotometry found soil concentrations following Pb > Cu > Cd in Owerri and Port Harcourt but Pb > Cd > Cu in Aba, while fish and vegetables followed Pb > Cd > Cu at all three sites. The deterministic assessment found cadmium's incremental lifetime cancer risk exceeded the US EPA acceptable threshold of 1×10⁻⁶ at every site for every sample examined, identifying cadmium as the metal of greatest concern.

Hoque MN, Rana ML, Gilman MAA, Pramanik PK, Islam MS, Punom SA, Rahman R, Hassan J, Rahman MS, Ramasamy S, Schreinemachers P, Oliva R, Rahman MT · Environmental Monitoring and Assessment · バングラデシュ・ダッカ／ガジプール

A shotgun metagenomic study motivated by how little is known about the microbial communities and antimicrobial resistance (AMR) profiles of rooftop and surface garden soils in Bangladesh, and their potential role as reservoirs and disseminators of AMR, despite the growing expansion of urban agriculture. Twenty-seven soil samples were sequenced — 7 from Dhaka rooftop gardens, 6 from Dhaka surface gardens, 8 from Gazipur rooftop gardens and 6 from Gazipur surface gardens. The work identified 88 antibiotic resistance genes (ARGs), of which 19 (21.6%) were shared across all sites, and found significant differences in resistome composition by garden type (p = 0.04). Rooftop soils harboured more ARGs (Dhaka 50, Gazipur 48) than surface soils (Dhaka 40, Gazipur 41) and were dominated by glycopeptide resistance genes, collectively 62.43-74.07% of ARGs; rooftop soils were also enriched in efflux pumps (adeF, 45.21% of rooftop ARGs) and the ribosomal-protection oxazolidinone resistance gene O23S (62.13% in Gazipur rooftops). Surface soils instead featured more genes mediating antibiotic inactivation, such as CATA (11.64% in Dhaka surface gardens) and fosBx1 (5.94% of surface ARGs).

Oyewole Michelle T., Pellow David N., Cassels Susie · Environmental Justice · 米国

A study measuring soil lead by X-ray fluorescence at 31 Brooklyn public schools with active garden programmes, sampling both garden beds and adjacent school grounds. Proximity to 306 known environmental hazard sites was mapped geostatistically and combined with demographic data and soil-management surveys. Of the samples, 42% exceeded the US EPA's minimum screening level for child-accessible soils near known lead sources (100 ppm); garden soils showed lower average lead concentrations than adjacent school-ground soils. The authors argue that soil lead in schools, and the disparities in it, have received far less attention than lead in paint and water.

Olabode K., Lewińska K., Komorowicz I. · Environmental Geochemistry and Health · ポーランド南部・ズウォティストク（旧鉱山地域）

Quantifies total arsenic, gastric-phase in vitro bioaccessible arsenic (IVBA) and direct-soil-exposure risks for children and adults in mining-affected allotment gardens in Złoty Stok, southern Poland, applying deterministic calculations and Monte Carlo simulation to incidental soil ingestion, dermal contact and inhalation of resuspended particles. Total As ranged 433–1148 mg/kg and IVBA 4.5–23.5%. Under the total-As multi-pathway scenario median hazard indices were 5.50 for children and 0.62 for adults (P05/P95: 2.26/15.18 and 0.29/1.89). Median total cancer risk was 1.78×10⁻⁴ for children and 1.06×10⁻⁴ for adults, with 80.0% of simulated child profiles and 54.0% of adult profiles at or above 10⁻⁴. Ingestion and dermal contact accounted for nearly all modeled risk while inhalation was negligible; applying IVBA to the ingestion pathway alone cut the median ingestion-related hazard quotient and cancer risk by 89.3%. Total soil As and soil ingestion rate were the principal positive risk drivers, body weight inversely associated.

Pritom Kumar Pramanik, M. Nazmul Hoque, Md. Liton Rana, Md. Saiful Islam, Md. Ashek Ullah, Fahim Haque Neloy, Srinivasan Ramasamy, Pepijn Schreinemachers, Ricardo Oliva, Md. Tanvir Rahman · PLOS ONE · Bangladesh (Dhaka)

Researchers sampled 145 items — 88 raw vegetables, 27 water and 30 soil samples — from rooftop and surface gardens in urban Dhaka North and Dhaka South City Corporations and peri-urban Gazipur City Corporation, Bangladesh, testing for Escherichia coli by culture, biochemical tests and malB-gene PCR. Overall prevalence was 58.62% (95% CI 50.48–66.31): 80.0% in Dhaka South, 44.70% in Dhaka North and 76.7% in Gazipur. In Dhaka, surface gardens were more contaminated (70.83%) than rooftop gardens (46.57%), while in Gazipur rooftop gardens were worse (93.33% vs 60.0%). Of 54 randomly selected isolates, 100% were resistant to ampicillin, with resistance to ciprofloxacin (25.92%), tetracycline (14.81%) and imipenem (9.25%); 14.81% were multidrug resistant and 81.48% carried blaTEM. Home-grown urban vegetables are not automatically hygienically safe.

Xiang Zhou, Nan Wang, Jiaying Shi, Michael Hensel · Humanities and Social Sciences Communications · China (Nanjing)

A study of urban foraging behavior in Nanjing's central urban area, China, revealed significant enthusiasm among residents, linking personal childhood experiences to their foraging motivations. However, environmental pollution was identified as a critical barrier to these activities.

Paula Marques Crelier, Manoel Jerônimo Moreira Cruz, Danusia Ferreira Lima · Seven Editora eBooks · Global

A controlled laboratory experiment cultivated BRS Leila lettuce (L. sativa) in samples contaminated with lithium carbonate (Li₂CO₃) at concentrations of 150 and 200 mol/L. The study found that lithium correlates with other alkaline and alkaline earth elements in the leaves and roots of the lettuce. This indicates a contamination pathway where lithium is absorbed by the plant.

Aminu Zakariyau, Murtala Rabiu · International Journal of Advances in Engineering and Management · Nigeria (Katsina City)

The potential ecotoxicological impacts of municipal solid waste compost (MSWC) on soil, plants, and humans in urban Katsina, Nigeria, were assessed. Analysis of soil mixtures and plant biomass (maize and beans) revealed high phytotoxicity in beans, while maize considered MSWC as phytonutrients. No statistical difference in non-biodegradable substance concentrations in soils and plants was found, and ecological risk index (ERI) indicated low risk; however, Target Hazard Quotients (THQ) suggested a likelihood of non-carcinogenic effects to the ecosystem.

Robert J. Moriarity, Meaghan J. Wilton, Eric N. Liberda, Tim Drew, Ada John, Howard Jeddore, Atanu Sarkar, Jim D. Karagatzides, Leonard J. S. Tsuji · Journal of Agriculture Food Systems and Community Development · Canada (Newfoundland)

This study aimed to develop safe community garden sites in Miawpukek First Nation, Newfoundland, Canada, addressing potential soil contamination. Soil testing revealed inorganic arsenic levels exceeding Canadian agricultural guidelines. Hügelkultur-style raised beds with imported soil were used, resulting in undetectable arsenic in potatoes grown there, while potatoes from contaminated soil exceeded safety limits. Kale grown in both raised beds and native soil remained within safety limits.

Godswill Ntsomboh Ntsefong · IntechOpen eBooks · Global

This chapter examines the global growth and implications of urban agriculture. While urban agriculture enhances food security, it also introduces food safety risks from contaminated soils and infrastructure gaps. Challenges related to heavy metals, waste, and inadequate land planning are evaluated, and barriers such as land access and limited training for producers persist.

M Mohan Joseph, Archana T. Anil · Environmental Quality Management · India (Kochi)

This study evaluated spider webs from Cyrtophora cicatrosa and Pholcus phalangioides as biomonitoring tools for heavy metal pollution in urban, industrial, and semi-urban/agricultural areas of Kochi city, India. Analysis of web samples revealed site-specific variations in Cr, Cu, Mn, Mo, Ni, Pb, Sn, and Zn concentrations, with high levels of Zn found in Eloor (7558 ppm) and Kizhakkambalam (4947.50 ppm). Zn and Sn were the dominant accumulated metals, indicating significant heavy metal contamination in these environments.

Christoph Koch, Maria da Glória Arrais Peter · Environmental Challenges · Germany

This citizen science study analyzed inorganic pollutants in private garden soils in central Germany, including front and backyards. Elevated levels of lead and copper were found in one-third of the samples, and zinc in two-thirds. Chromium and nickel concentrations were also elevated in a quarter of the samples, with some readily available substances exceeding limit values.

Christian Valderrama, Hernan Zarate · Ambiente & sociedade · Colombia (Neiva)

This research characterized the presence and spatial distribution of lead (Pb) concentrations in Mangifera indica and Syzygium malaccense fruit trees on public roads in Neiva, Colombia. Using a census, fruit sampling, and spatial interpolation methods, lead levels were detected in all samples. Five samples exceeded the permissible limit of 0.1 mg/kg, with higher concentrations observed in industrial areas.

Corina Başnou, Geovana Mercado, Åsa Ode Sang, Thomas B. Randrup, Verónica Fabio, Adrián Cabezas, Arnau Lluch, Marc Montlleó, Juan Miguel Kanai, Riccardo Saraco, Olívia Bina, Tom Wild · Nature-Based Solutions · Europe

An overview and guidance for air pollution indicators in nature-based solutions (NBS) for urban green planning and public health were provided, using three case studies in Europe and Latin America. The study noted that approaches including multidimensional indicators in research, planning, and policies are limited, and national standards for some air pollutants are missing with little evidence for health effect thresholds. Findings also indicated that knowledge of pollutant uptake in edible plants can suggest potential human exposure risks.

Taffere Addis, Sisay Ketema, Abayneh Melaku · Frontiers in Water · Ethiopia (Addis Ababa)

This study in Addis Ababa, Ethiopia, investigated trace metal levels in sediment, soil, and irrigated vegetables from farms along the Akaki River, evaluating public health risks. Sediment levels of arsenic, chromium, copper, nickel, lead, and zinc exceeded threshold effect levels. Soil levels of arsenic, chromium, copper, manganese, and zinc exceeded typical world soil values, with nickel at one site exceeding EEC limits for agricultural soils. Critically, arsenic, lead, and zinc levels in some vegetable samples were above WHO allowable limits, despite soil levels being acceptable, and cadmium was the most accumulated metal in vegetables.

E. Ryan Harrelson, Qingyue Zeng, Mairui Gao, Magaly Toro, Ryan A. Blaustein · Frontiers in Plant Science · United States (Washington, D.C.)

This study analyzed 87 multidrug-resistant (MDR) bacterial strains from leafy greens (n=29), root zone soil (n=42), and bulk soil (n=16) in Washington, D.C. urban agriculture systems using whole genome sequencing. The isolates, spanning 4 phyla and 14 genera, carried diverse antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs). The results indicate that MDR bacteria are present in urban agriculture systems, including on fresh produce, dominated by soil-associated taxa carrying diverse ARGs and MGEs, which suggests implications for resistance mobilization.

Doreen N. Meso, Enos W. Wambu, Gelas Simiyu, Shem M. Mwasi, Thomas Munyao · Discover Environment · Kenya (Kakamega Town)

This study assessed heavy metal pollution in agricultural soils, water, and pumpkin leaves from 21 sites across three zones in peri-urban Kakamega Town, Kenya. It found cadmium pollution in all water samples, and lead and nickel pollution in sections of soil and leafy vegetable samples. Lead pollution was linked to vehicular emissions near the town center, while cadmium enrichment in informal settlements implicated inadequate waste management. Sequential extraction showed 31–35% of soil cadmium was in exchangeable fractions, posing a risk of bioavailability, highlighting persistent heavy metal contamination with implications for public health, environmental sustainability, and agricultural productivity.

Dariusz Gruszka, Katarzyna Szopka, Cezary Kabała · Land · Poland (Wroclaw)

This study in Wroclaw, Poland, investigated the quality of constructed technogenic soils in urban gardens located on a reclaimed clay pit. Despite beneficial physicochemical properties and high fertility in the topsoil layers, the soils were seriously contaminated with trace elements, including zinc (up to 1700 mg kg−1), lead (920 mg kg−1), copper (740 mg kg−1), cadmium (5.1 mg kg−1), mercury (7.4 mg kg−1), and arsenic (5.1 mg kg−1). This contamination, likely from industrial and urban waste used for mine infilling, compromises soil quality and poses potential health and ecological risks.

Haofan Xu, Peng Hu, Hailong Wang, Peter Croot, Zhiwen Li, Cheng Li, Shaowen Xie, Hongyi Zhou, Chaosheng Zhang · Environmental Pollution · China

This study in Gaoming county, China, integrated PMF and K-means clustering to identify sources and contamination patterns of 8 potentially toxic elements (PTEs) in peri-urban agricultural soils. Average concentrations of PTEs were reported, with PMF identifying geogenic, industrial/traffic-related, and agricultural sources. The highest PTE concentrations were found in urbanized zones, confirming significant human impact and underscoring the dual influences of agriculture and urbanization on PTE contamination.

Ebenezer Boahen · Discover Agriculture · Ghana

This study assessed the awareness and practices of 50 purposively selected vegetable farmers along the Accra-Tema Motorway, Ghana, regarding heavy metal contamination from vehicular emissions and its potential health implications. Data were collected through structured questionnaires and one-on-one interviews. Results showed that 96% of the farmers were unaware of heavy metal contamination, though 80% expressed a willingness to discontinue farming near the motorway if they were informed of the risks. Farmers face challenges such as limited access to clean irrigation water and dependence on informal agricultural knowledge. The study highlights the urgent need for targeted educational interventions to raise awareness about the risks of heavy metal exposure and to encourage safer farming practices.

Katja Hombrecher · Gefahrstoffe Reinhaltung der Luft · Germany

A pilot study in Germany investigated the impact of road traffic emissions on food plants grown near roads. Bioindicators like kale, chard, Lollo Rosso, and lettuce were exposed for four weeks at four roadside locations and compared to plants in a garden away from roads. While pollutant levels generally did not exceed background or EU maximum limits, significant traffic-related inputs of PAK 4, antimony, aluminum, chromium, and vanadium, and lesser inputs of copper, iron, and lead were detected compared to the control. The findings indicate a potential contamination risk for certain vegetable plants from road traffic.

YAO, Kouadio Assemien François, OUEDRAOGO, Moussa, BROU, Konan Richmond, COULIBALY, Léréyaha, OUATTARA, Ismaïla, N'CHO, Odon Clément, YAO, Koffi Blaise · Zenodo (CERN European Organization for Nuclear Research) · Côte d'Ivoire

Nine groundwater samples were collected in March 2025 from urban farming areas of the Man municipality, western Côte d’Ivoire, to assess their physicochemical and metallic quality. Analysis revealed high concentrations of major ions and nitrites (up to 101.7 mg/L) in the groundwater, exceeding WHO standards. Extreme pollution by cadmium, iron, and zinc was confirmed, with an overall contamination degree of 793.6. These groundwaters are unsuitable for human consumption and require regular monitoring and sustainable water resource management.

Carithers, Jaci, Gowen, Samantha, Jenney, Francis · Digital Commons - PCOM (Philadelphia College of Osteopathic Medicine) · United States (Atlanta)

A study in a Metro Atlanta residence, United States, analyzed lead contamination in soil and plant samples using inductively coupled plasma mass spectrometry (ICP-MS). The research found substantial lead contamination, particularly in areas where crops were grown. Results demonstrated the propagation of lead from contaminated soil into local vegetation over time, with an average level of 143.9 mg/kg, ranging from 5.1 mg/kg to 499.5 mg/kg.