Research & reports

Cecilia Herbón, María Teresa Barral, Remigio Paradelo · Applied Sciences · Spain (Santiago de Compostela)

The concentrations of trace elements Cu, Pb, Zn, Ni, Cr, and As were investigated in 55 urban soils in Santiago de Compostela, northwestern Spain. While most soils showed higher trace element concentrations than regional backgrounds, they were not classified as contaminated according to Spanish regulations. However, geoaccumulation index values indicated low to moderate pollution levels in most soils, with Cu, Pb, and Zn highest in city center green areas, and Cr and Ni linked to parent material lithology.

Elisabeth Ziss, Wolfgang Friesl‐Hanl, Sophia Götzinger, Christoph Noller, Markus Puschenreiter, Andrea Watzinger, Rebecca Hood‐Nowotny · Sustainability · Europe

In the "Heavy Metal City-Zen" citizen science project, community members in urban gardens in Vienna, Austria collaborated on collecting soil and plant samples to assess heavy metal contamination risk. Trace metal concentrations were generally below guideline thresholds, but at a few garden sites soil concentrations of lead, cadmium and zinc exceeded Austrian recommended limits, and at two sites plant trace metal concentrations exceeded European food standard limits; the project proposes expanding the citizen-led sampling to all of Vienna so new gardens can assess local soil risk before planting.

Yuliia V. Medvedeva, Анатолій Кучер, Joanna Lipsa, Maria Hełdak · International Journal of Environmental Research and Public Health · Europe

A study assessed the safety of apples sampled across different functional zones of Kharkiv, Ukraine — from industrial areas to school gardens — for consumption. Heavy metal levels exceeded maximum allowable limits in apple samples from all sampling sites, with lead 11.47 to 38.86 times and cadmium 1.76 to 5.68 times the FAO/EU norms; the most contaminated samples came from residential areas, partly due to significant land pollution from various waste types. Hazard index (HI) values varied by age group: 24.37-70.11 for children aged 1-6, 10.28-29.59 for children aged 7-16, and 0.88-2.53 for adults aged 18-65. Non-carcinogenic risks were linked to disorders of the immune, blood, urinary, and nervous systems and to liver and kidney function, and the total carcinogenic risk from eating the apples exceeded the permissible level.

Małgorzata Ćwieląg‐Drabek, Agata Piekut, Klaudia Gut, Mateusz Grabowski · Scientific Reports · Europe

A study of family allotment gardens (FAGs) in Silesia Province, one of the most polluted regions in Poland, analyzed 219 soil samples and 64 edible plant samples to link the geochemical disturbance caused by past mining and smelting activity to consumer exposure to toxic and carcinogenic metallic trace elements. Contents of these elements in topsoil were spatially diverse and depended primarily on the location of industrial pollution sources. Average cadmium (0.52 mg/kg fresh weight) and lead (0.57 mg/kg fresh weight) content in vegetables exceeded maximum permissible concentrations under European quality standards. A human health risk assessment based on three dietary exposure scenarios found that, in every scenario, potatoes — a staple of the Polish diet — carried the highest average daily dose for all three elements. The study concludes that consuming vegetables grown in Silesia Province's family allotment gardens may pose a significant health risk to consumers.

Anna Margenat, Víctor Matamoros, Sergi Dı́ez, Núria Cañameras, Jordi Comas, Josep M. Bayona · Environment International · Spain (Barcelona)

A study assessed 16 trace elements and 33 organic microcontaminants in lettuce, tomato, cauliflower, and broad beans from peri-urban farms near Barcelona, Spain, and a rural site. Concentrations ranged from non-detectable to 17.4 mg/kg for trace elements and non-detectable to 256 μg/kg for organic microcontaminants, with tomatoes showing the highest levels. Risk assessment indicated a low human health risk from consuming these vegetables in the peri-urban area, comparable to the rural site.

Christine Aubry, Nastaran Manouchehri · OpenEdition (OpenEdition) · France (Paris)

Urban and peri-urban agriculture is exposed to various forms of pollution related to cultivation methods and urban air and soil quality, with different crop types exhibiting varied reactions to pollutants. The T4P and REFUGE programs on urban farms in the Paris region, and the ADURAA and QUALISANN programs studying vegetable-growing in Antananarivo, Madagascar, aim to assess health risks and oversee practices using methodological frameworks.

Anne Barbillon, Christine Aubry, François Nold, Stéphane Besançon, Nastaran Manouchehri · Agricultural Sciences · France

This study assessed health risks from soil trace metals (lead, cadmium, mercury, copper, and zinc) at three urban farms near Paris (Ile-de-France region), evaluating two main exposure pathways: soil and vegetable ingestion. All three farms had soil trace-metal levels above geochemical background values and the thresholds used in France as reference values for sludge spreading. Using a Hazard Quotient (HQ)-based risk assessment (HQ being the ratio of estimated daily intake to tolerable daily intake), the riskiest scenarios were urban farmers working on-site daily year-round (HQtot = 1.02), child gardeners (HQtot = 1.29), and regular child consumers eating exclusively the farm's vegetables under a maximalist scenario (HQtot = 1.6). The adult gardener scenario followed (HQtot = 0.9), while the lowest-risk scenarios were adult consumers (HQtot = 0.62) and farm workers (HQtot = 0.45).

Anne Barbillon, Christine Aubry, Nastaran Manouchehri · HAL (Le Centre pour la Communication Scientifique Directe) · France

This French guide, "R.E.F.U.G.E.," developed by AgroParisTech, sets out a four-step methodology to help urban-planning actors in the Île-de-France region assess and manage soil contamination risk before establishing urban agriculture on available land: a historical and environmental site study, a sampling strategy, interpretation of soil analyses, and, where warranted, a formal health risk assessment. Based on France's national methodology for managing polluted sites and soils, it is intended as a first harmonized technical tool for the field and was slated for a testing phase applying it to future urban agriculture projects. The abstract itself does not report contamination measurements or findings from any specific site; it describes the assessment procedure rather than presenting soil contamination data.

Martin Dawson, Mike Hutchins, Nuria Bachiller‐Jareno, Steven Loiselle · Freshwater Science · United Kingdom (London)

A citizen-science study from 2014 to 2016 assessed water quality in a 5.6-ha urban community garden in southwestern London, using borehole water. Measurements of specific conductance and tryptophan-like fluorescence were taken over 28 months. The study found no evidence of external contamination sources or temporal changes in water quality. However, significant variations in water quality between boreholes were directly linked to on-site manure storage and use, and local geological conditions.

Cécile Le Guern, Liliane Jean‐Soro, Béatrice Bechet, Thierry Lebeau, Dorine Bouquet · Land Degradation and Development · France

Urban allotment gardens in Nantes, France, were found to have soil contamination, with lead (Pb) levels ranging from 100–400 mg kg−1, posing health risks. Local actors collaborated to characterize soil, evaluate sanitary risks, and discuss management options. The most frequent solution was replacing polluted soils with clean soils, while other strategies included on-site management of excavated soil, non-accumulative cropping, or changing land use.

Piotr Krzyk, Bogusława Kwoczyńska · Problemy Drobnych Gospodarstw Rolnych / Problems of Small Agricultural Holdings · Poland (Cracow)

This study quantitatively assessed the conversion of agricultural land to investment purposes in Cracow's Mogiła and Wyciąże neighborhoods from 2010-2013, based on local plans. It also addressed soil quality, heavy metal content, and pH. Analysis of spatial management plans for these areas indicated a systematic decline in the share of biologically active areas.

Mireia Ercilla‐Montserrat, Pere Muñoz, J.I. Montero, Xavier Gabarrell, Joan Rieradevall · Journal of Cleaner Production · Spain (Barcelona)

This study measured heavy metal content in air and hydroponic lettuce leaves at four sites in Barcelona, including high-traffic areas, to assess potential contamination from atmospheric pollution. The results showed that heavy metal concentrations in lettuce leaves were below EU-legislated limits in all cases, and air concentrations were less than 50% of legislative limits. The study concluded that Barcelona's air heavy metal content is low and not a source of contamination for urban crops, even near high-traffic areas.

Jane Entwistle, Patrick M. Amaibi, John R. Dean, Michael E. Deary, Daniel Medock, Jackie Morton, Ilia Rodushkin, Lindsay Bramwell · Environment International · United Kingdom

This study assessed gardeners' lead exposure in urban agriculture sites (UAS) to improve the derivation of soil assessment criteria. Researchers sampled nearly 280 paired soil and crop samples across 31 UAS gardens in the United Kingdom and measured blood lead levels (BLL) of 43 gardeners and 29 non-gardening neighbors. While 98% of sampled soils had lead concentrations above the current UK UAS soil guideline (80 mg/kg), all participants' BLL were below 0.1 mg/kg despite high soil lead. The study indicated that soil-to-plant concentration factors (SPCFs) used for UAS significantly over-predicted lead uptake.

Marthe Ortolo · Infoscience (Ecole Polytechnique Fédérale de Lausanne) · Netherlands

This study outlines a plan to assess air pollution risks in urban agriculture in the Netherlands, focusing on heavy metal (Cd, Hg) and PAK accumulation in spinach in Amsterdam urban gardens. It includes a literature review, policy maker interviews, and practical measurements of airborne contamination. The study aims to model different uptake routes by plants, but actual findings on contamination levels are not presented in this abstract.

Marta Bożym · Ochrona Środowiska i Zasobów Naturalnych · Poland

A study measuring heavy-metal content (cadmium, lead, copper, zinc, nickel, chromium) in compost and resident earthworms sampled from home composters and allotment gardens in the Opole region of Poland. The compost samples themselves were not contaminated with heavy metals and stayed within Polish legal limits for solid organic fertilizers. However, metal accumulation in earthworms varied by metal: the bioaccumulation factor (BAF) was high for cadmium, lead and zinc, while no accumulation was found for nickel, chromium or copper. The authors conclude that earthworm species native to Poland, such as Eisenia fetida, can serve as potential bioindicators of metals in the environment.

Eduardo De Miguel, Miguel Izquierdo‐Díaz, Amaia Gómez, Juan Mingot, Fernando Barrio‐Parra · Environmental Toxicology and Chemistry · Spain (Madrid)

Forty-two soil samples from seven urban gardens in Madrid, Spain, were collected to measure concentrations of arsenic, antimony, and selenium, along with soil properties. Antimony concentrations exceeded recommended values for agricultural use in 70% of the urban gardens. A human health risk assessment indicated acceptable levels for noncarcinogenic and carcinogenic risks, though carcinogenic values were elevated, with arsenic identified as the main risk driver.

Andrew Hursthouse, T. E. Leitão, Annette Voigt, Avigail Heller, Béatrice Bechet, Paulo Brito da Luz · HAL (Le Centre pour la Communication Scientifique Directe) · Europe

This chapter overviews factors influencing the chemical, physical, and biological status of soils, water, and the biosphere in urban allotment gardens. It highlights that urban garden soils, water, and biosphere are affected by pollution due to their location in city centers or suburbs, with traffic infrastructure and industrial zones widely identified as impacting soil and water quality. Concerns over long-term risks from pollutant transfer (mainly metals) from soil to plants in these uncontrolled environments have been widely publicized.

Piotr Godyń, Maria Zielińska, Agnieszka Dołhańczuk-Śródka, Zbigniew Ziembik · Geology Geophysics & Environment · Poland

Soil samples were collected from 19 sites around the Opole industrial zone in Poland to determine the influence of the local metallurgical industry on soil contamination with metals, using Pb-210 as a contamination tracer. Results indicated that the metallurgical industry is not a source of environmental pollution in the immediate vicinity. Excessive lead concentrations ranged from 1 Bq/kg d.m. to 100 Bq/kg d.m. but were not strongly correlated with distances from the presumed source of contamination.

Marcelo Ortega Romero, Juan Mingot Marcilla, María Jesús García Martínez, Eduardo de Miguel, Miguel Izquierdo‐Díaz, Amaya Gómez · · Spain (Madrid)

This study evaluated the potential health risk from trace elements in urban garden soils in Madrid, Spain. Thirty-six composite soil samples were collected from the top 20 cm of six urban gardens, and concentrations of cobalt, chromium, copper, nickel, lead, and zinc were determined. The findings indicated that urban soils are significantly enriched in trace elements relative to background levels, suggesting a potential health risk.

Mucig Charlotte · · France

A survey on rainwater harvesting in community gardens in France indicates that while this practice has been ongoing for years, it is poorly documented and faces challenges in adapting to new French regulations. The findings highlight public health issues for both garden users and consumers of fruits and vegetables, as well as environmental and operational concerns.

Vittori Antisari, Livia; Dipartimento Di Scienze E Tecnologie Agroambientali, University Of Bologna, Bologna, Serena Carbone, Ferronato, Chiara; Dipartimento Di Scienze E Tecnologie Agroambientali, University Of Bologna, Bologna, Simoni, Andrea; Dipartimento Di Scienze E Tecnologie Agroambientali, University Of Bologna, Bologna, Vianello, Gilmo; Dipartimento Di Scienze E Tecnologie Agroambientali, University Of Bologna, Bologna · Archivio istituzionale della ricerca (Alma Mater Studiorum Università di Bologna) · Italy (Bologna)

Concentrations of heavy metals (Ba, Cd, Co, Cr, Cu, Ni, Pb, V, Zn) were determined in topsoil, plants, and moss tissues in the suburban area of Bologna, Italy, due to an urban waste incinerator and other atmospheric emission sources. No correlation was found between metal content and the incinerator plant's distance. The pollution load index (PLI) for soil and moss indicated low environmental pollution, but the highest values in sites downwind of the incinerator and in a craft area indicated moderate pollution.

Zbigniew Ziembik, Agnieszka Dołhańczuk-Śródka, Grzegorz Kusza · Proceedings of ECOpole · Poland

Soil samples were collected from the former "Piast" cement plant within Opole city borders, Poland, and nearby allotment gardens to study radioisotope activity concentrations. Naturally occurring radioisotopes and artificial Cs were found, with K and Cs showing the biggest radioactivity concentration. No significant differences in radionuclide activities were found between soil samples from the former industrial estate and the allotment gardens.

Anna‐Katarina Schilling, Helmut Hotzel, Ulrich Methner, Lisa D. Sprague, Gernot Schmoock, Hosny El‐Adawy, Ralf Ehricht, Anna-Caroline Wöhr, Michael Erhard, Lutz Geue · Applied and Environmental Microbiology · Germany

This study investigated the presence of zoonotic agents in small ruminants kept on city farms in southern Germany, sampling feces and nasal liquid from 48 animals (28 goats, 20 sheep) across 7 city farms and one activity playground. Findings revealed that 100% of sampled sheep and 89.3% of goats carried Shiga toxin-producing Escherichia coli (STEC). Staphylococcus spp. were detected in 75% of both sheep and goats, and Campylobacter spp. in 25% of sheep and 14.3% of goats. Neither Salmonella spp. nor Coxiella burnetii was found.

Cezary Kabała, T. Chodak, L. Szerszeń, Anna Karczewska, Katarzyna Szopka, Urszula Fratczak · Fresenius environmental bulletin · Poland (Wroclaw)

An analysis of 180 allotment garden soils in Wroclaw, Poland, found that concentrations of Cu, Pb, and Zn (12.5-659 mg Pb kg-1, 38.1-2103 mg Zn kg-1, 12.9-595 mg Cu kg-1) were influenced by industrial pollution sources, organic matter, pH, and macronutrients. Soils in gardens on former housing or industrial areas had significantly higher metal concentrations. Up to 35% of soils in the city zone were excessively contaminated, making them unsuitable for vegetable and fruit production and requiring reclamation.

C. Paul Nathanail, Caroline McCaffrey, Naomi Earl, Neil D. Foster, A. G. Gillett, Richard Ogden · Human and Ecological Risk Assessment An International Journal · United Kingdom

This paper describes a deterministic method for deriving Site-Specific Assessment Criteria (SSAC) in the UK for human health risks from chronic exposure to heavy metals, metalloids, and organic substances in soil. The SSAC indicates soil concentrations above which unacceptable health risks may occur, considering standard and non-standard land uses and various exposure pathways. The method is not intended to generate or replace UK Soil Guideline Values, as this is the responsibility of UK authoritative bodies.