Research & reports

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.

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.

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.

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.

Subhash Aswal, Harshal Purohit, P. K. Gupta, K. K. Yadav, Laxman Jat, Shipra Jaiswal, R. A. Kaushik · International Journal of Plant & Soil Science · India (Kota)

A quarterly survey in Kota district, Rajasthan, India, characterized wastewater-irrigated soils by comparing them with tube well water-irrigated soils from ten urban sites. The study found decreased sand content, pH, and dehydrogenase activity, while porosity, EC, BOD, COD, OC, available-NPK, SO4, Cl, and heavy metals (Mn, Fe, Zn, Cu, Ni, Cd, Pb, Cr) increased. Some parameters exceeded Indian standard permission limits, indicating contamination, with highest values observed in summer.

Hae Jong Yang, Tae‐Woo Kang, Byungwoong Choi, Soon Hong Hwang, Dongseok Shin, Won-Pyo Park · Sustainability · South Korea

This study verified heavy-metal pollution levels in sediments of an urban-agricultural watershed in the Yeongsan River basin, South Korea, through evaluation of Sediment Quality Guidelines (SQGs), a pollution load index (PLI), and a potential ecological risk index (PERI), and analyzed statistical relationships between pollution levels, land use, and potential pollution sources. Pb, Zn, Cu, Cd, and Hg concentrations were highest at mid-upstream sites, while As, Cr, and Ni concentrations were similar across most sites. Sites showing potential toxicity to benthic organisms relative to SQGs were most frequently observed at mid-upstream, and PLI and PERI evaluations likewise confirmed high anthropogenic pollution and ecological risk there. Mid-upstream sites with high heavy-metal pollution correlated strongly with urban land use — the largest land-use category — indicating links to population density and industrial complexes; statistical analysis confirmed this relationship. The findings indicate that urban areas are highly likely to cause anthropogenic heavy-metal pollution of sediments via point and non-point sources such as domestic sewage and industrial wastewater.

Seema Purushothaman, Sheetal Patil, Raghvendra S. Vanjari, A. R. Shwetha · · India (Bengaluru)

A participatory assessment in Byramangala, Bengaluru, explored farmers' perspectives on using wastewater (domestic sewage with industrial effluents) for irrigation. The study found that farmers were adapting to a heavily polluted environment, which resulted in restricted crop choices, lower produce prices, health impacts, and socio-cultural consequences. Despite concerns about water quality, farmers prioritized health-imparting agriculture and were keen to continue farming, but their preference for treated wastewater was overshadowed by its potential diversion for urban use.

Dong BaoCheng, Wei Li, Wenyong Xu · Antibiotics · China

A field experiment in peri-urban agricultural soil in China investigated the effects of partially substituting chemical fertilizer with organic fertilizers like pig manure and sewage sludge on soil quality and antibiotic residues. Organic substitution significantly increased residual antibiotic levels in agricultural soil, with antibiotic sequestration rising by 138.1~332.5%. This indicated that organic fertilizers can promote antibiotic persistence in soil by modifying soil quality, demonstrating a contamination risk.

Xingjia Wang, Wenbo Li, Dongyan Wang, Songze Wu, Zhuoran Yan, Jiaqi Han · Ecological Indicators · China

A 'trinity' assessment method was developed to evaluate heavy-metal contamination in peri-urban soil–crop systems in Northeast China, covering total, available, and accumulated heavy metals. While traditional methods indicated less contamination, the trinity method revealed spatial clustering of heavy-metal contamination in cultivated lands caused by urbanization and industrialization, and a decreasing urban–rural trend in contaminated areas, particularly in transition zones.

Mila Siti Fatimah, M.S Ir. Eko Hanudin, Ph. D. Toru Watanabe · · Vietnam

This study investigated heavy metal contamination in soils, vegetables, and irrigation water in peri-urban agricultural areas of Hue, Vietnam, from May 2018 to January 2019. Samples from three sites revealed that while irrigation water and agricultural soils were not seriously contaminated, 14% of vegetables were contaminated by Cr, 76% by Cd, and 47% by Pb. The consumption of vegetables was categorized as a tolerable health risk.

Wojciech Mrozik, Soydoa Vinitnantharat, Thunchanok Thongsamer, Nipapun Pansuk, Pavinee Pattanachan, Parinda Thayanukul, Kishor Acharya, Marcos Quintela‐Baluja, Charles R. E. Hazlerigg, Aidan Robson, Russell J. Davenport, David Werner · The Science of The Total Environment · Asia

A study of three family-owned peri-urban aquaculture operations downstream of Bangkok, Thailand — spanning extensive, semi-intensive and intensive practices — used micropollutant analysis, genetic markers and 16S rRNA amplicon sequencing to assess water quality against aquaculture standards. Canals draining Bangkok did not meet quality standards and were sources of faecal coliforms, Bacteroides, Prevotella, human E. coli, tetracycline-resistance genes and nitrogen entering the ponds, causing algae blooms. The aquacultures in turn discharged salinity and the herbicide diuron into the canals; diuron was detected in shrimp, though not at a level of concern to human health. The extensive aquaculture attenuated an estimated 20 population equivalents of nitrogen pollution and trillions of faecal coliform inputs per year.

M. L. Dotaniya, V. D. Meena, S. Rajendiran, M. Vassanda Coumar, Asha Sahu, J. K. Saha, S. Kundu, Hiranmoy Das, A. K. Patra · Journal of the Indian Society of Soil Science · India (Bhopal)

A case study in peri-urban agricultural lands near Patranala, Bhopal, India, investigated the impact of over 50 years of untreated sewage water irrigation on soil properties. Findings showed higher concentrations of heavy metals in surface soils of sewage-irrigated fields, posing a major concern. Conversely, soil microbial population, enzymatic activities, and organic carbon content were also higher, indicating enhanced carbon sequestration.

Dan Luo, Haifeng Zheng, Ye Chen, Philippe Deleporte, Tianpeng Xie, Siobhán Staunton, G. Wang · Soil Use and Management · China (Fujian Province)

A large-scale survey across 515 sites and 24 crop species in Fujian Province, SE China, assessed nickel (Ni) accumulation in food crops and associated dietary health risks. Crop Ni content was influenced by both soil Ni (DTPA-extractible) and plant species, though PCA did not show strong correlations between soil-to-crop transfer factors and soil properties. The study concluded that dietary intake of foods with mean Ni content could lead to health risks, particularly for children, and that sandy soils rich in organic matter with high Ni content are unsuitable for growing rice and legumes.

Kamal Kishore Yadav, Pradeep Kumar Singh, R. C. Purohit · Water science and technology library · India (Udaipur)

A study in the peri-urban area of Udaipur City, India, investigated heavy metal contamination in soil, vegetable crops, and groundwater due to wastewater reuse. While groundwater-irrigated vegetables showed heavy metal levels within WHO limits, wastewater-irrigated spinach, tomato, and radish at site 3 (Kanpur – Madri Villave) exceeded maximum permissible limits for Fe, Zn, and Cd. Urban wastewater-irrigated spinach was found to accumulate Fe, Zn, and Cd significantly above permissible limits at all three selected locations, making it unsafe for human consumption.

Arti Bhatia, Shivdhar Singh, Amit Kumar · Water Environment Research · India (Delhi)

A study in Delhi, India, investigated heavy metal contamination (cadmium, lead, zinc, copper) in irrigation water, soil, and vegetables from four peri-urban and one wholesale site. Most samples from peri-urban areas exceeded safe limits for lead and cadmium. Vegetables from the wholesale market showed only higher lead concentrations. Among peri-urban vegetables, only okra exceeded the safe limit for cadmium, while several wholesale vegetables (potato, coriander, chilies, pea, carrot) exceeded the limit for lead regarding health risk.

Prem José Vazhacharickal, Sumita Gupta Gangopadhyay · Kobra (Universitätsbibliothek Kassel) · India

This paper examines urban and peri-urban agriculture (UPA) in India, focusing on wastewater irrigation and its associated human health risks. The study identifies potential health hazards for farmers, laborers, and consumers, including microbial pathogens and helminth (intestinal parasites). While UPA is presented as an option to address urban food demand, the paper emphasizes that "good practice UPA" requires integrated approaches and suitable risk reduction mechanisms to improve safety.

K.G. Rosin, Ravinder Kaur, Sushma Singh, Prabhat Kumar Singh, Digvijay Dubey · Procedia Environmental Sciences · India

A study was conducted in peri-urban agricultural sites around Faridabad, Haryana, India, to assess groundwater contamination and the contribution of salt/trace metal-laden irrigation waters. Mean EC, Cl, and F concentrations in root zone leachates were found to be far beyond permissible limits, and some trace metals posed a threat to deep percolating waters. However, due to existing cropping patterns and deeper water table depths, the groundwaters were not yet vulnerable to these salts/trace metals, and the presence of salts in the groundwaters was primarily geogenic.

Shazia Iram, Iftikhar Ahmad, Doris Stüben · Pakistan Journal of Botany · Asia

Soil samples were collected from peri-urban agricultural land in Lahore, Pakistan, irrigated by industrial and sewerage waste from the Hudiara drain, and from mine waste soil in Wiesloch, Germany, and analyzed for heavy metals by X-ray fluorescence and ICP-MS and for fungal diversity and frequency by a soil dilution method. X-ray fluorescence found higher Zn, As and Pb in the German mine waste soil, and the more sensitive ICP-MS found higher Fe, Mn, Cu, As, Sr, Mo, Cd, Sb, Ti, Zn and Pb there as well; the Pakistani peri-urban soils had lower heavy metal concentrations than the German mine waste but higher overall fungal frequency and diversity. Testing radial growth of isolated Aspergillus niger, A. flavus and A. nodulans against CdCl2, CuSO4, NiCl2 and ZnCl2 at 1-40 ppm, all tested fungi tolerated ZnCl2 (25 ppm) and NiCl2 (12 ppm) but none tolerated CdCl2 or CuSO4.

Euis Suryaningsih · Jurnal Hortikultura · Indonesia (Bandung)

From January to July 2001, a field experiment on vegetable disease control in a mosaic farming system in periurban agriculture was conducted at a farmer's field in Rancaekek, Bandung, Indonesia. Treatments included white plastic net cages, biorational pesticides, Bacillus subtilis, a mixture of Mancozeb and Bacillus subtilis, and an unsprayed control. All tested alternative control methods were very effective against major diseases of chili pepper, shallot, eggplant, beans, and cucumber, but the use of poisonous synthetic pesticides in periurban agriculture increases the likelihood of contaminating humans and the environment.

XU Yong-xian, Biao Huang · Soils · China

A study of a small-scale vegetable farming system in peri-urban Nanjing, China, monitored heavy metal balances and pollution potential from July 2003 to July 2004. Heavy metals entered the soil mainly through fertilization and irrigation, with organic manure application accounting for more than 98% of inputs. Annual heavy metal input in the area was significantly higher than in European farmland, while annual output was very low, under 10% of input, leading to accumulation of heavy metals in the plots; long-term vegetable cultivation had already caused heavy metal buildup in the soils. Copper, lead, zinc, and cadmium concentrations in vegetables and soil were still below national safety standard limits, so the vegetable farming system was assessed as currently safe. However, an evaluation that incorporated atmospheric deposition showed the region carries a high risk of copper, zinc, and cadmium contamination, and the study concludes that intensive vegetable cultivation will aggravate soil heavy metal pollution, potentially pushing the soil to Second Grade of the National Soil Environment Quality Standard within several decades.

Do Thuy Trang, Kåre Mølbak, Phung Dac Cam, Anders Dalsgaard · Tropical Medicine & International Health · Vietnam (Hanoi)

A cross-sectional study in a peri-urban area of Hanoi, Vietnam, surveyed 400 agricultural households and examined 807 stool samples from 620 adults and 187 children for helminth infections. The study found that 39% of samples were infected with helminths, with Ascaris sp. at 21.6%, Trichuris sp. at 9.8%, and hookworm at 21.8%. Wastewater exposure was not a major risk, but lack of sanitation facilities and use of fresh or inadequately composted human excreta in agriculture were important risk factors for infection.

Nigel Poole, DS Bhupal, Fiona Marshall, Dolf te Lintelo · · India

New knowledge is presented on the impacts of urban and peri-urban (UPU) environmental pollution on food safety attributes of vegetable marketing systems in India. Air pollution reduces crop yield and nutritional quality, and is a major source of particulate contaminants that accumulate at toxic levels in edible crops. The study explores the balance between public and private quality assurance initiatives and identifies wholesale markets as a potential entry point for quality assurance.