Research & reports

Johanna F. Lindahl · · Vietnam

The circulation of Japanese encephalitis virus (JEV) in pigs and mosquitoes was investigated around Can Tho city in Vietnam's Mekong Delta. Of 315 sows, 60% were JEV seropositive, and seropositivity was associated with more stillborn piglets in sows under 1.5 years old. Among 7885 mosquitoes collected in and around Can Tho city, seven pools collected near pigs tested positive for JEV, indicating co-circulation of JEV genotypes I and III. All 43 pigs sampled within Can Tho city were JEV seropositive, demonstrating that JEV can be a public health issue in urban areas.

Qing Tian · · China (Beijing)

Based on Agricultural Location Theory, 23 matched soil-wheat sample sets were collected from Beijing's central city, suburban plain and exurban plain zones to analyze the accumulation, chemical forms and bioavailability of lead under differing intensities of human activity. Urban soil showed lead contamination with an average concentration of 35.59 mg/kg above the limit, likely from traffic and industrial emissions, and suburban agricultural soil also showed localized lead contamination from long-term sewage irrigation, with lead more mobile in urban agricultural soil than in suburban soil and least mobile in exurban agricultural soil. The average bioconcentration factor of lead in wheat seeds was a low 0.0044, but some lead concentrations in wheat seeds grown in urban and suburban agricultural soil exceeded the standard limit, indicating a potential health risk to residents in those areas.

김혁수, 김영남, 김진원, 김계훈 · 한국토양비료학회지 · South Korea (Seoul)

This study investigated the physicochemical properties and heavy metal (Cd, Pb, Cu, Zn) contents in 21 urban agricultural soils in Seoul. The total heavy metal concentrations in these soils were found to be lower than the warning levels specified by the Soil Environmental Conservation Act of Korea for area 1. Phytoavailable concentrations of Cu, Pb, and Zn were also reported.

Hyuck-Soo Kim, Young‐Nam Kim, Jin‐Won Kim, Kye-Hoon Kim · 한국토양비료학회지 · South Korea (Seoul)

This study investigated the properties and total and phytoavailable contents of heavy metals (Cd, Pb, Cu, Zn) in 21 urban agricultural soils in Seoul, South Korea. The total heavy metal concentrations in the examined urban agricultural soils were found to be lower than the warning levels for area 1 according to the Soil Environmental Conservation Act of Korea. Phytoavailable-Cu, -Pb, and -Zn concentrations were also reported as 0.02-0.28, N.D-0.09, and 0.01-0.43 mg/kg, respectively.

Zhou Pei · · China (Shanghai)

A study conducted in Orchard Village, Nanhui District, Shanghai, from July to September 2009, investigated the effects of phosphorus non-point source pollution on groundwater in an urban agricultural region. Total phosphorus concentrations averaged 1.31 mg/L and phosphate concentrations averaged 0.42 mg/L, with phosphate significantly exceeding the V class surface water standard (0.4 mg/L), rendering the water unsuitable for drinking. Phosphorus non-point source transport was linked to land-use types, with phosphorus content near orchards changing with increased rainfall, and farmland phosphorus loss accelerating with runoff, fertilization, and water leach.

Zhou Pei · · China (Shanghai)

A study from July to September 2009 in an orchard village, Nanhui District, Shanghai, investigated the characteristics of non-point source nitrogen pollution in groundwater. Total nitrogen and its three forms (NO3-N, NH4-N, NO2-N) were monitored, revealing NO3-N as the main form (average 1.43-13.71 mg/L). Nitrogen pollution in groundwater depended on land use, with NH4-N pollution most serious under residential areas (average 0.074-0.457 mg/L). Total nitrogen pollution near the river and orchard (average 33.67-62.57 mg/L and 33.05-65.04 mg/L) was more severe than under residential areas.

Xiaona Li · Nongye huanjing kexue xuebao · China

A study measuring dioxin-like compound (PCDD/Fs) concentrations in 23 surface soil samples collected from different areas of Baiyin City, China, using HRGC/HRMS (high-resolution gas chromatography/high-resolution mass spectrometry). The concentration range of 2,3,7,8-PCDD/Fs was 0.42-8.56 pg I-TEQ/g, averaging 2.28 pg I-TEQ/g. By land-use type, concentrations averaged 3.37 pg I-TEQ/g in industrial areas, 1.31 in urban areas, 1.01 in agricultural areas, and 0.85 in background areas, following the order industrial > urban > agricultural > background. Higher-chlorinated isomers were the dominant contributors to total toxic equivalency (TEQ) in most samples.

W.-L. Rao, Z.-K. Zhang, Runzhong Li · Plant Disease · China (Kunming)

In June 2007, sweet cherry trees with mottling and mosaic symptoms were observed in a private garden near Kunming, Yunnan Province, China. Twenty-four samples from sweet cherry, sour cherry, flowering cherry, and peach trees in private and community gardens were tested for eight viruses by RT-PCR. Cherry virus A (CVA) was detected in two symptomatic sweet cherry trees, marking the first report of CVA in sweet cherry in China.

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.

Abha Singh, Salahuddin Mohd. · National Geographical Journal of India · India

In-depth field research around the Iglas sewage pumping station on the Aligarh-Mathura road in Aligarh, India, surveyed 41 farming households and some consumers across five peri-urban villages — Bhojpura, Hari Narayan ki Sarai, Hajipur Chohata, Kheri Khwaja Buddha and Daurala Nirpal — that had used urban wastewater for irrigation for many years. Farmers and vegetable sellers reported suffering from ailments including diarrhoeal disease, typhoid fever, hookworm, amoebiasis and skin infections, yet their primary concern was securing enough water to sustain crop productivity and income, while consumers were more focused on getting a fresh, steady supply of vegetables than on the health risk.

Seyed Esmaeil Mahdavian, R. Somashekar · ePrints@Bangalore University (Bangalore University) · India (Bangalore)

A study in Bangalore city, India, showed that urban consumers are at greater risk of purchasing fresh fruits with high levels of heavy metals beyond the legally permissible limits defined by the Indian Prevention of Food Adulteration Act, 1954. These national norms are less strict than international food safety standards.

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.

Jianguo Dai · Journal of Shenzhen Polytechnic · China (Shenzhen)

Urban agriculture in Shenzhen faces problems including decreasing farmland, inadequate skilled farmers, poor disaster resistance, immature insurance, increasing contamination of water, soil, air, and agricultural products, and poor modern enterprise management. Strategies proposed for sustainable development include specific laws, pollution protection, education, research, technology application, industrial technology application, leisure agriculture development, and diversification.

R. B. Singh · IAHS-AISH publication · India

A study on wastewater management in 300 class-I cities and 23 metropolitan cities in India found that the total wastewater generated is approximately 158x10^8 l/day, with treatment capacity being only 375x10^7 l/day. In metropolitan cities, only 30% of wastewater is treated before disposal, and most cities only have primary treatment facilities. Untreated water is being used for urban agriculture, posing risks to public health and potential surface and groundwater pollution.

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.

L.M. van den Berg · WIT transactions on ecology and the environment · Africa, Asia

Urban agriculture, despite severe competition for space, plays roles such as fresh food supply, leisure, supplementary income for the urban poor, and green space management. Case studies in Africa and Southeast Asia demonstrate the difficulty of maintaining these roles due to public health and environmental degradation concerns. Urban agricultural producers may rely on polluted streams for irrigation, cause soil erosion through inappropriate farming techniques, or poison surrounding residents with pesticides. The paper suggests that urban agriculture could be more beneficial to the urban system if treated by town planners as a normal urban function requiring both regulation and protection.