Research & reports

Abdul Rahim Mohammed Sabtiu, Isaac Amankona Hinne, Isaac Kwame Sraku, Daniel Kodjo Halou, Richard Tettey Doe, Simon K. Attah, Fred Aboagye‐Antwi, Yaw A. Afrane · Malaria Journal · Ghana (Accra)

A study in Accra, Ghana, investigated mosquito larval habitats and their impact on Anopheles gambiae s.l. larvae density, conducting surveys at 15 locations during 2022's dry and rainy seasons. Of 727 potential habitats, 65.34% were positive for Anopheles larvae, with drainage ditches being the most common type. Irrigated urban farming sites showed the highest abundance of An. gambiae s.l. larvae, particularly during the rainy season, indicating that urban farming contributes to increased mosquito breeding habitats.

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.

Blessing Nyamasoka‐Magonziwa, Esther Simango, Hatirarami Nezomba · Frontiers in Agronomy · Zimbabwe (Chitungwiza)

This study evaluated climate-smart crop production practices by urban farmers in Chitungwiza District, Zimbabwe, and their effects on household diets. Mixed methods research, including focus group discussions with four farmer groups and interviews with 107 households in 2022, classified only 23% of farmers as climate-smart. While climate-smart crop production positively influenced household diets, with climate-smart households having a significantly higher Household Dietary Diversity Score (3.3 vs. 2.9; p=0.02), there were no significant differences in maize yield between climate-smart and non-climate-smart farmers (2.10 t/ha vs. 2.27 t/ha, respectively, in the 2020/2021 season).

Álvaro Luis José Reyes Córdova · Horizontes Amazónicos · Ecuador

A bibliographic review of research on water quality in the Puyo River and its tributaries in Pastaza, Ecuador, compiled studies from scientific databases and institutional repositories reporting physicochemical, microbiological, and heavy metal parameters. The main sources of contamination were found to be wastewater discharges, fecal coliforms, and accumulation of heavy metals such as lead and mercury linked to urban, agricultural, and mining activities, with community perception aligning with technical findings as most of the population rated the water poor quality and associated it with health problems. Over the past twenty years, a progressive deterioration in water quality parameters has been documented, with increases in turbidity and pathogenic microorganisms despite some isolated recovery efforts, and the review concludes that lack of attention from the municipality and prefecture, together with the absence of continuous monitoring, is worsening the water crisis and demands comprehensive, participatory governance.

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.

Pierre‐Alexandre Deyris, Franck Pélissier, Claire M. Grison, Claude Grison · Journal of Hazardous Materials Advances · Global

Herbicide use worldwide has doubled over the past 30 years, and diuron contamination of tropical aquatic ecosystems — affecting food crops such as pineapple — has been reported across Southeast Asia, the Pacific, and Africa. This perspective article examines taro (Colocasia esculenta), a widely cultivated crop whose tubers are consumed locally, as a nature-based means of mitigating diuron impact on tropical aquatic ecosystems through rhizofiltration, i.e., phytoaccumulation of the herbicide by the roots. Analysis of treated tubers found that diuron levels in the tuber core were below recommended European standards, indicating the tubers could remain edible for the local population and confirming compatibility with existing food uses.

Sarah Corcoran, Rachael Condley, Rachel A Liebe, Tuba Khan, Jillian Joyce, Deana Hildebrand, Ashlea Braun · Journal of Hunger & Environmental Nutrition · United States (California)

At a hybrid food and resource center with an attached community garden in California, USA, a longitudinal, sequential explanatory mixed-methods study of 30 patrons (mean age 45.9, 73.3% women) combined quantitative measures (survey and skin carotenoids) with qualitative semi-structured interviews to examine barriers to and facilitators of fruit and vegetable intake. Skin carotenoid levels, a biomarker of fruit and vegetable intake, were largely unchanged before and after (P = .51); among the 26 participants interviewed, facilitators cited included perceptions of quality and alignment with health goals, while barriers included mental health and competing priorities, leading to the conclusion that programs aiming to improve fruit and vegetable intake should prioritize non-diet determinants.

Abubakar Mohd Habu, Ali Sanusi Hassan, Adeniyi Olarewaju Adeleye, Michael Edet Nkereuwem, Ijanu Emmanuel Madu, Garba Barde Bate, Olukemi Adeleye, Usman Mohammed Isah · Biological Environment and Pollution · Nigeria

This study assessed heavy-metal accumulation and non-carcinogenic health risks in commonly consumed leafy vegetables -- lettuce, spinach, and cabbage -- cultivated with wastewater in Zawaciki, Kano State, Nigeria. Vegetable and rhizospheric soil samples were analyzed for cadmium, lead, chromium, nickel, zinc, and copper using atomic absorption spectrophotometry, and bioaccumulation factors (BAFs) were calculated as the ratio of metal levels in plant tissue to soil. Metal concentrations varied significantly across the vegetables (p < 0.05), with lead in lettuce leaves exceeding the FAO/WHO permissible limit by more than 120 times; chromium in cabbage reached 32.22 mg/kg, while lettuce showed elevated zinc (19.83 mg/kg) and copper (9.26 mg/kg). Hazard-quotient risk assessments found HQs for chromium and lead both exceeding 1, and the cumulative hazard index exceeded 1 for all vegetables, reaching its highest value of 18.861 in lettuce.

Jan Grossarth · Discover Cities · Global

This paper critically examines the dominance of quantification—certification scores, KPIs, life-cycle assessment—in sustainability practice for cities and buildings (including urban agriculture), arguing that data-driven metrics strip out the emotional and narrative meaning of sustainability. The authors label the shift from a culturally rich orientation to a purely technical, quantitative practice a "tragedy of sustainability," and argue that narrative-focused interviews and real-life storytelling in architecture and urban planning should not just accompany KPIs and ratings but be prioritized over them. The paper is a conceptual argument, not an empirical study with data or case findings.

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.

Jarosław Chmielewski, Barbara Gworek, Alicja Walosik, Magdalena Florek-Łuszczki · Annals of Agricultural and Environmental Medicine · Poland

Soil (N=196) and root vegetable (N=94) samples from 16 allotment gardens in Warsaw, Poland, were analyzed for manganese, zinc, copper, lead and cadmium and assessed for health risk. Parsley, carrots, beetroots and celery grown in these gardens accumulated elevated levels of all five metals, and the health risk assessment found an increased risk of carcinogenic effects from cadmium and lead in consumers of these root vegetables; the authors conclude consumption of vegetables from the examined gardens should be very limited or eliminated from the diet entirely.

Ikrema Hassan, Innocent Mugudamani, Saheed Adeyinka Oke · Environments · Canada

Top and subsoil samples from Carleton community garden in New Brunswick, Canada, affected by an industrial fire hazard, were analyzed for toxic heavy metals using ICP-OES and ICP-MS, with ecological risk assessed via the ecological risk factor and potential ecological risk index (PERI) and human health risk assessed using a standard approach. Mean concentrations of lead, zinc, copper and tin exceeded permissible limits under Canadian soil quality guidelines and upper continental crust values; nickel posed a high ecological risk across both soil layers while all other metals showed low ecological risk, and overall PERI indicated low ecological threat. In the human health assessment, children faced non-carcinogenic and carcinogenic risk from arsenic exposure while adults did not face risk from any of the metals studied, identifying arsenic as the primary contaminant of concern and children as the most vulnerable population.

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.

Kelley AT, Boger R · EcoHealth · 米国・ニューヨーク市ブルックリン

A survey of mosquito larval abundance and genera across 22 community gardens in Brooklyn, New York. The authors frame these gardens as social spaces providing food sovereignty to many New Yorkers, while the arrival of Aedes albopictus and the longtime presence of Culex pipiens make socialising in them more dangerous — Ae. albopictus is associated with dengue, Zika and chikungunya, and Cx. pipiens is a longstanding West Nile virus vector. Because both breed in human-made plastic containers, knowing their preferred container types and locations can inform gardeners' best management practices. Non-purposeful container types and lower total volumes of water were significant predictors of higher mosquito densities, though these variables did not predict egg-laying preference.

U.S. Environmental Protection Agency · U.S. Environmental Protection Agency (EPA) · United States

This EPA page (last updated December 22, 2025) explains chromated copper arsenate (CCA), a wood preservative used since the 1940s for utility poles, posts, and other structural lumber. Manufacturers voluntarily ended CCA use for residential wood products in December 2003. EPA notes cancer and non-cancer health risks for workers and environmental risks to aquatic invertebrates and plants, while stating there is no health risk to the general public; removal of existing CCA structures is not mandated, though periodic sealant coating is recommended to reduce leaching.

Chmielewski J., Wszelaczyńska E., Pobereżny J., Florek-Łuszczki M., Gworek B. · Sustainability · Poland

The study sampled 112 items — 72 vegetable and 40 fruit — from 16 allotment gardens in Warsaw and measured Fe, Mn, Zn, Cu, Pb and Cd. Vegetables accumulated markedly more heavy metals than fruits, and leafy vegetables grown near high-traffic roads carried the highest Pb, Cd and Zn. Lead exceeded permissible limits by six to twelve times and cadmium by one to thirteen, leading the authors to advise against growing tomatoes in urban settings. Only trace amounts appeared in fruits, and the Hazard Index rated the fruits alone as safe. The paper calls for continuous monitoring of urban garden soils, remediation of contaminated ground and safer growing practices.

Wendy Demark-Wahnefried, Robert A. Oster, Kerry P. Smith, Harleen Kaur, Andrew D. Frugé, W. Walker Cole, Julie L. Locher, Gabrielle B. Rocque, Maria Pisu, Jennifer R. Bail, Harvey Jay Cohen, Douglas R. Moellering, Cindy K. Blair · JAMA Network Open · United States (Alabama)

A randomized trial in Alabama, USA, assigned 381 older cancer survivors (mean age 69.8 years, 69.0% female) with suboptimal vegetable and fruit intake, physical activity or physical function to a one-year home vegetable gardening intervention (supplies plus mentoring by certified master gardeners) or to a waitlist. The primary outcome — a composite index of improvement in vegetable and fruit intake, moderate-to-vigorous physical activity and physical function — did not differ significantly (4.5% intervention vs 3.1% waitlist, P=.53), nor did vegetable and fruit intake between arms (mean difference 0.3 servings/day, P=.10). The intervention arm did show significant gains in physical performance (2-minute step test +6.0 steps; 30-second chair stand +0.8 repetitions), perceived health (+8.4 points on a 100-point scale) and gut microbiome alpha diversity. The COVID-19 pandemic significantly moderated effects, so the trial does not establish that gardening halts functional decline in older adults.

Zhe Zhu, Faith Ka Shun Chan, Gang Li, Mengxia Xu, Meili Feng, Yong‐Guan Zhu · Soil & Environmental Health · China

This review examines urban agriculture in China, identifying three forms: small-scale, capital-intensive, and tourism-type, each with benefits and challenges shaped by local context and government policies. Despite benefits like improved community cohesion and environmental sustainability, urban agriculture in China faces significant limitations including land availability, capital shortage, market access, and insufficient governmental support. Strategies and four recommendations are proposed to address these challenges.

Yizhou Peng, Grigorieva Iya Yu · Ecological Indicators · China (Chengdu)

This study assessed heavy metal pollution in rural, urban-rural interface, and urban agricultural lands in Chengdu, China. It found varying degrees of heavy metal pollution across all areas, with arsenic (As) and cadmium (Cd) being the most severe pollutants. Concentrations of As and Cd in soil samples exceeded risk thresholds, and these elements showed high spatial variability, indicating significant anthropogenic influence. Pollution sources included livestock manure, natural sources, agricultural activities, and industrial activities in urban areas.

Roopika Sivaraman, Haritha Thulaseedharan Nair, Sharmila Krishnan, Perumal Siddhuraju · Soil and Sediment Contamination An International Journal · India (Coimbatore)

This study analyzed biocompost and water samples from four agricultural nurseries in semi-urban Coimbatore, India, for microplastic contamination using density separation and ATR-FTIR. While physicochemical properties met Indian standards, microplastic fragments (85%) and fibers (15%) were found in two biocompost samples (BC-B and BC-C), identifying PMMA, PP, and EVA polymers. No microplastics were detected in samples BC-A and BC-D, but the findings suggest semi-urban agricultural gardening may contribute to microplastic accumulation in terrestrial environments, potentially harming soil and plant health.

Sreejith Aravindakshan, Hage Aku, Michi Tani · · India

This study investigated factors inducing the emergence, sustenance, and sustainability of urban agriculture using primary data from urban farming households in Kerala and Arunachal Pradesh, India. The research indicates that urban agriculture has provided questionable environmental gains and has not significantly improved urban food security, especially among the poorer sections.

Beatriz Barbosa da Silva, Caroline Senatore, Manueli Monciozo Domingos, Jackline Freitas Brilhante de São José · Ensaios e Ciência C Biológicas Agrárias e da Saúde · Brazil (Vitória)

From March to May 2023, the microbiological quality of food and medicinal plants, soil, and irrigation water was evaluated in an urban garden at an educational institution in Vitória, Brazil. 16.6% (n=2) of the analyzed plants exceeded legal limits for total coliforms at 35ºC, and Salmonella spp. was detected in 41.6% (n=5) of plants. Salmonella spp. was also found in 80.0% (n=4) of soil samples, suggesting a potential source of plant contamination.

Prajal Pradhan, Daya Raj Subedi, Kshitij Dahal, Yuanchao Hu, Prakriti Gurung, Sijal Pokharel, Sagar Kafle, Biplav Khatri, Sudeeksha Basyal, Monika Gurung, Aruna Joshi · Cell Reports Sustainability · Global

This systematic analysis of 1,450 urban agriculture publications examined its impacts on Sustainable Development Goals (SDGs). It found urban agriculture is linked to all SDGs, with 142 targets showing positive sentiments and 136 showing negative sentiments, with positive sentiments roughly double the negative. The study concludes that urban agriculture does not inherently contribute to sustainability, as its impacts depend on specific practices and require tackling identified hurdles.

Laura S. Tuominen, Heikki Helanterä, Patrik Karell, Lauri Rapeli, Timo Vuorisalo, Jon E. Brommer · npj Urban Sustainability · Finland (Turku)

This before-after study in Turku, Finland, examined the influence of the COVID-19 pandemic on urban box gardening from 2019 to 2021. While box gardening's importance for resilience increased and gardeners remained motivated, participants reported receiving fewer benefits from gardening during the pandemic. This suggests a negative influence of the pandemic on well-being, extending to urban gardening outcomes.

Beata Sirowy, Deni Ruggeri · ˜The œGeojournal library · Global

This chapter reflects on urban agriculture practices in public spaces, emphasizing their unique role in the individual and communal well-being of city dwellers. It concludes with a brief reflection on the future trajectories for urban agriculture practices in compact cities.