Research & reports

Mohamed Haythem Msaddek, Mohsen Ben Alaya, Lahcen Zouhri, Yahya Moumni, Bilel Abdelkarim · Water · Global

This study developed a Geo-AI ensemble modeling framework to assess groundwater contamination dynamics in peri-urban agricultural aquifers. Applied to the Manouba aquifer in Tunisia using 295 samples from 85 wells (2005-2025), the spatial analysis revealed severe contamination expanded from 7% of the study area in 2005 to 55% in 2025. Urban expansion and agricultural intensification were found to reduce recharge, increase pollutant loading, and accelerate contaminant accumulation.

L Cao, Jingsheng Wang, Yanbin Zhao (1549129), Shuping Zheng, Ruike Pan, Ruiqi An (19738761), Xuhui Yue, Yifan Wang (380120), Jianan Li (290570), Yan Liu (25061), Jie Wang (16762), Peng Wang (34436), Yangmei Mo, Ning Pan (186987), H. Z. Shi, Jiayin Dai (218672), Kun Zhang (108291) · Figshare · China (Shanghai)

An integrated assessment of agrochemical contamination in Shanghai's peri-urban agricultural surface waters across 193 sites revealed exceptionally high chemical diversity and mixture complexity. 91 pesticides and 263 formulation adjuvants were widely detected, with adjuvants showing comparable detection frequencies and response intensities to pesticides, indicating they are a major, underappreciated component of agrochemical pollution. In vivo zebrafish embryo assays showed that representative pesticides and adjuvants induced adverse developmental effects at environmentally relevant concentrations, identifying peri-urban agriculture as a critical source of complex agrochemicals.

Ndiaye Awa, Diallo Ibrahima, Dieng Amadou, Ba Ibrahima, Sembene Mbacke · African Journal of Environmental Science and Technology · Senegal

This study in Dakar, Senegal, assessed Salmonella contamination in irrigation water and lettuce across three urban agricultural sites. Sites using wastewater (Pikine and Patte d’Oie) showed high Salmonella prevalence in water (70-90%) and vegetables (20-80%), while a tap water site (Lendeng) had no contamination. Market-sourced lettuce also tested positive (28.57%), indicating public health risks from untreated wastewater use.

Réné Kasende Disashi, Belloty Mundadi Ngeteke, Dorcas Sola Tabitha, Prescilia Mabubu Pembe, Fanny BAKOMBA KIKOBO, Denise OKITO WIKANU, Esther MPIANA MUKANIA, Sarah Kinsona Bombili, Esther Kimpala Karuna, Clément Munganga Kilingwa, Rosie Mubindukila Nzamba · European Scientific Journal ESJ · Congo (Kinshasa)

A study conducted from June 10 to July 20, 2025, in peri-urban market gardens of Kimwenza and Ndjili Cecomaf in Kinshasa, Democratic Republic of Congo, surveyed 68 market gardeners on the use of prohibited and unauthorized pesticides. The findings revealed an alarming reliance on informal supply channels, with six out of 27 identified pesticides being formally prohibited. Despite 94.3% of gardeners acknowledging risks, only 9.6% used full protective equipment, and 32.7% took no precautions.

Nelson Joseph Msacky, Amelia Alfred, Oscar Punguti, Edson Protas, Iddi Mapande, Novatus, Shukrani Phillip, January G Msemakweli · Open MIND · Global

This systematic review aims to synthesize current scientific evidence on the effectiveness of fruit-waste-derived biochar in immobilizing potentially toxic elements (PTEs) in contaminated agricultural soils. It will evaluate how fruit-waste biochar reduces metal bioavailability, plant uptake, and associated human health risks from vegetable consumption. The review also seeks to identify which fruit wastes are used as biochar feedstocks and which biochar properties and production conditions influence immobilization performance, noting that existing research is fragmented.

Hajra Kanwal, Qudrat Ullah, Waqas Haider, Mujahid Farid, Zaki Ul Zaman Asam, Muhammad Zubair, Abdulrahman Alasmari, Sarah Owdah Alomrani, Muhammad Munir, Shafaqat Ali · Open MIND · Global

This study investigated the interactive effects of contaminated wastewater with cadmium, mercury, lead, and polyethylene microplastics from exfoliating personal care products on chili plants (Capsicum annuum). Plant growth parameters were reduced by 71–82% at high wastewater and microplastic levels, accompanied by significant losses in photosynthetic pigments and soluble proteins. Oxidative stress markers increased by 124–230%, and heavy metal uptake was significantly increased, facilitated by microplastics.

Pari Diwahar, Chandran. S, Paramasivan SatheeshKumar · International Journal of Drug Delivery Technology · India (Madurai District, Tamil Nadu)

This study in Kaluvankulam, Madurai District, India, assessed the adaptability of treated municipal wastewater for marigold irrigation, where paddy yields have declined. Analysis of treated wastewater showed oil and grease and chemical oxygen demand (COD) levels exceeded permissible irrigation standards. Soil analysis revealed elevated phosphorus, potassium, and iron concentrations, indicating nutrient accumulation.

Michael J. Ormsby, Luke Woodford, James Joseph Mwesiga, Winnie Ernest, Dativa J. Shilla, Daniel Abel Shilla, Richard S. Quilliam · Environmental Pollution · Africa

This study investigated plastic debris as a reservoir for multidrug-resistant (MDR) enteric bacterial pathogens at two peri-urban agricultural sites in Dar es Salaam, Tanzania. Analysis of 140 environmental samples (soil, water, vegetation, plastic debris) showed higher concentrations of culturable pathogens on plastic debris, with presumptive E. coli loads of ~1 × 10^3 CFU per piece. Plastic debris harbored a greater proportion of MDR strains, including E. coli and K. pneumoniae resistant to critically important antimicrobials, indicating that plastic waste facilitates the survival of MDR pathogens and poses health risks.

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.

Candice M. Duncan, Fatemeh Ghezelsofla, Hlengilizwe Nyoni, Jazmin Escobar, Odette Mina · Toxics · United States

A study measuring per- and polyfluoroalkyl substances (PFAS) in irrigation water at two organic farms in Maryland, USA, with no known direct PFAS input, and assessing health risk via a Hazard Index (HI). At agricultural site 1 (AG1), the most abundant compounds were PFBS (37 ng/L), PFBA (24 ng/L) and PFHxA (22 ng/L); the HI showed compliance for branched PFHxS (0.39) but non-compliance for linear PFHxS (1.51). At agricultural site 2 (AG2), despite no known industrial or PFAS-related facilities nearby, HFPO-DA (GenX) was detected at 28 ng/L, and the HI exceeded the compliance threshold (HI = 2.83), with GenX accounting for most of the calculated risk. The findings show HI exceedances occurring at small farm sites with no identifiable contamination source.

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.

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.

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.

Laxman Barua, YOGITA ADHIKARI, Kuldeep Naik · International Journal of Agriculture and Nutrition · India (Prayagraj)

This research assessed heavy metal concentrations in agricultural soils near the Naini industrial area in Prayagraj, India, and evaluated remediation strategies. Lead and cadmium concentrations at 0.5 km from the industrial zone exceeded Indian permissible limits (Pb: 67.8 mg/kg vs 50 mg/kg; Cd: 6.4 mg/kg vs 5 mg/kg). A pot trial showed that Brassica juncea removed 34.7% of Pb and 41.2% of Cd, while lime + biochar reduced Pb by 52.4%. A combined approach reduced bioavailable Pb to below the permissible limit.

Justin B. Richardson, Eric Vukicevich, Eric C. Sirkovich · Bulletin of Environmental Contamination and Toxicology · United States

Soils, sap, and maple syrup were collected from four artisanal maple syrup producers in four suburban areas across the northeastern United States to assess nutrient and trace element concentrations. Soil arsenic and lead concentrations approached or exceeded EPA limits. Sap and syrup arsenic, cadmium, nickel, lead, and zinc concentrations reached or exceeded FDA limits for food.

Jacek Antonkiewicz, Iwona Paśmionka, Grzegorz Szychowski · Soil Science Annual · Poland

Following a flood that inundated allotment gardens in Nysa, southern Poland, for up to 14 days after the water rose on 14 September 2024, researchers analyzed 12 soil samples collected in early spring 2025 from two allotment garden sites. Most soils were found limed and disinfected, with high organic matter but low total potassium, sodium and sulfur. Zinc and copper concentrations exceeded the average for Polish arable soils, pointing to use of materials enriched with these elements.

Md. Rafiqul Islam, Syed Anisur Rahman, Tanvir Ahmed · International Journal of Agriculture and Food Science · Asia

Six heavy metals (lead, cadmium, chromium, nickel, copper, zinc) were measured by atomic absorption spectrophotometry in spinach, amaranth and fenugreek collected from four peri-urban sites around Dhaka, Bangladesh, during January-March 2024, where more than 2,000 hectares of vegetable land are irrigated with untreated industrial and domestic wastewater via canal networks. Lead in amaranth from the industrial-effluent site reached 0.94 mg/kg fresh weight, more than three times the WHO/FAO permissible limit of 0.30 mg/kg, while cadmium, chromium and nickel stayed within permissible limits at all sites and zinc, though highest in absolute terms (8.6-14.7 mg/kg), also remained within safe limits; contamination was highest at the industrial-effluent site and lowest at the borewell-irrigated control site, indicating a localized food-safety risk for consumers of peri-urban leafy greens grown with wastewater irrigation.

Jennifer Newell, Siobhan Cox, Rory Doherty · Urban Agriculture & Regional Food Systems · Global

A systematic review synthesized literature on the oral bioaccessible fraction (BAF) of arsenic, cadmium, chromium, nickel, and lead in vegetables grown on contaminated soils, drawing values from multiple online databases across potentially toxic elements (PTEs), in vitro test methods, and vegetable types. The review starts from the premise that many urban and peri-urban brownfield sites carry a legacy of soil metal and metalloid contamination, so crops grown there may pose human health risks. Median PTE BAFs ranked Cd > Ni > Cr > As > Pb; among in vitro methods, the unified BARGE method (UBM) produced the highest median BAFs (63.0% gastric, 59.6% gastrointestinal); and by crop type, BAFs ranked non-vegetables (e.g., rice, fungi) > legumes > root vegetables > bulb vegetables > leafy vegetables.

José Luis Chaves, Alexandre Boleira Lopo, G. M. OLIVEIRA, J. F. ARAÚJO, Luciano Sérgio Ventin Bomfim, J. A. CASTRO · Editora Científica Digital eBooks · Global

This systematic review investigated the viability of animal production in urban and peri-urban agriculture as a tool for food security, using the PRISMA methodology. The review found that while this practice offers benefits like domestic food security and income generation, it also presents negative aspects such as odors, noise, and the transmission of zoonoses. Public policies are needed to regulate the activity and minimize health risks.

Dragana Šunjka, Sanja Lazić, Slavica Vuković, Siniša Berjan, Hamid El Bilali · · Serbia

This chapter examines the food safety of urban agriculture systems in the Republic of Serbia through selected case studies. It highlights that agricultural products from urban production may be contaminated by polluted soil, water, and air, as well as by pesticides, heavy metals, persistent organic pollutants, nitrate and nitrite, and mycotoxins. The study emphasizes the need for strict control and reduction of synthetic pesticides and other agrochemicals in urban agriculture.

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.

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.

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.

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.