Research & reports

Bruce Frayne, Jane Battersby, Robert Fincham, Gareth Haysom · · South Africa

This study examines urban food security in South Africa, focusing on Cape Town, Msunduzi, and Johannesburg, and includes a critique of the City of Cape Town's urban agriculture policy. The abstract indicates that the policy was found to have significant shortcomings, particularly concerning local production and access to food. The research highlights various policy issues related to food access, dietary diversity, local production, and local markets within these urban contexts.

Shahzad Kouser, Mr. Abedullah, Abdus Samie · The Pakistan Development Review · Pakistan (Faisalabad)

This study, conducted in 2006 with 200 farmers in two peri-urban villages of Faisalabad, Pakistan, estimated the economic values of negative health externalities from wastewater use in cauliflower production. While wastewater use appeared profitable without considering externalities, factoring in health costs strongly discouraged its use. The health externalities for a three-month cauliflower crop on 741 acres amounted to Rs 3.2 million, and for 5,283 acres of vegetables cultivated with wastewater in Faisalabad, the annual total was Rs 90.7 million. The findings indicate a significant economic loss due to wastewater use, suggesting that installing a water treatment plant is a viable option to minimize these external effects.

Y. A. Iyaka, SE Kakulu · African Research Review · Nigeria

This study determined the levels of copper (Cu) and zinc (Zn) in soil samples collected from cultivated farmlands near abandoned industrial sites in Minna and Bida, Niger State, Nigeria, using flame atomic absorption spectrophotometry. Concentrations ranged from 12-89 mg Cu kg-1 and 2.8-41 mg Zn kg-1 for Minna, and 2.4-6.5 mg Cu kg-1 and 0.57-36 mg Zn kg-1 for Bida. Apparent accumulation of Cu was found in Minna cultivated farmlands, with a mean Cu content of 24 ± 22 ppm, which was almost five times that of the control soils. Other mean values were similar to soil background averages.

Justin Stoler, John R. Weeks, Arthur Getis, Allan G. Hill · American Journal of Tropical Medicine and Hygiene · Ghana (Accra)

A 2003 study in Accra, Ghana, surveyed 3,164 women to examine the relationship between self-reported malaria and proximity to urban agriculture (UA). The odds of self-reported malaria were significantly higher for women living within 1 km of UA compared to those living near an irrigation source, with the association disappearing beyond this distance. Malaria prevalence was often elevated in communities within 1 km of UA, even with more favorable socioeconomic characteristics.

Stefan Dongus, Dickson Nyika, Khadija Kannady, Deo Mtasiwa, Hassan Mshinda, Laura Gosoniu, Axel Drescher, Ulrike Fillinger, Marcel Tanner, Gerry F. Killeen, Márcia C. Castro · Geospatial health · Tanzania (Dar es Salaam)

A cross-sectional survey in urban Dar es Salaam, Tanzania, investigated the influence of agricultural and geographical features on Anopheles larvae presence. The study found that agricultural areas, covering over 5% of the 16.8 km2 study area, had a 1.7 times higher proportion of habitats containing Anopheles larvae compared to other areas. However, breeding sites originating from urban agriculture accounted for less than a fifth of all malaria vector breeding sites in the city.

Lei Yan-hua · · Australia

This paper discusses the state of therapeutic horticulture in Australia, describing the field as largely project-driven with little government or philanthropic funding to sustain long-term growth. It notes that recent initiatives in community gardens, school and children's gardens, and horticultural therapy services have expanded the scope of activity and, while still small compared with many other countries, are high-profile, community-led, and have secured significant government funding. However, the paper states that this needs to be balanced against numerous barriers facing the sector: insufficient research, limited organization and representation, few education and training opportunities, and a lack of outreach and community services.

Nigel L. Webb, Harrison Kasumba · Africanus Journal of Development Studies · South Africa

In Ezibeleni near Queenstown, Eastern Cape, South Africa, a sustainable-development framework was used to gather empirical findings on vegetable crop cultivation, covering duration of crop consumption, the value of produce to households, environmental benefits, and social/psychological benefits. Both the scale of cultivation and the benefits obtained were found to be modest, reinforcing prior studies that focused on the actual practice of urban agriculture rather than its hypothetical potential.

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.

Sophie Graefe, Eva Schlecht, Andreas Buerkert · Outlook on Agriculture · Niger (Niamey)

Semi-structured interviews with 130 households in Niamey, Niger, characterized urban and peri-urban agriculture (UPA) and assessed resource use. The study found high use of livestock manure and indiscriminate use of nutrient-loaded wastewater for irrigation, leading to significant nutrient surpluses in UPA gardens. Initial calculations suggested large gaseous emissions of nitrogenous compounds and and leaching of nitrogen, phosphorus, and potassium to groundwater.

Eveline Klinkenberg, Philip J. McCall, Michael D. Wilson, Felix P. Amerasinghe, Martin J. Donnelly · Malaria Journal · Ghana

This study investigated the impact of urban agriculture on malaria transmission risk in Accra, Ghana, through larval and adult mosquito surveys. It found that Anopheles spp. and Culex quinquefasciatus outdoor biting rates were three and four times higher, respectively, in areas around agricultural sites compared to areas far from agriculture. The annual Entomological Inoculation Rate (EIR) was also higher in agricultural areas (19.2) than non-agricultural areas (6.6), suggesting that urban agricultural areas may increase malaria transmission risk by providing resting sites for adult mosquitoes.

Erastus K. Kang’ethe, Delia Grace, Thomas F. Randolph · East African Medical Journal · East Africa

This study synthesizes current knowledge on urban agriculture (UA) in East Africa, focusing on its human health impact. It identifies UA as an important source of food security, but notes that many zoonotic and food-borne diseases are associated with it, with a lack of evidence on human health impact and management. Major constraints include illegality and limited access to inputs and markets, indicating a need for more research to understand both positive and negative health impacts.

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.

Andréa Andreis, Graziela Maria Schuh, Rejane Giacomelli Tavares · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) · Brazil (Novo Hamburgo)

An evaluation of parasite contamination in playground soils at Horta Comunitária Joanna de Angelis in Novo Hamburgo, RS, Brazil, detected rhabditoid larvae in 33% of soil samples. An enteroparasitological survey (n=22) confirmed parasitism in 59.10% of samples. However, it was not possible to establish a correlation between the presence of parasitosis in children and in the soil.

Chris Hillbruner, Rebecca Egan · Food and Nutrition Bulletin · Bangladesh (Dinajpur)

A study in Dinajpur, Bangladesh, from 2002 to 2003, investigated the impact of seasonality on food security and nutritional status in approximately 600 low-income urban households. Data collected through surveys and child measurements revealed significantly higher rates of food insecurity, wasting, and inadequate growth during the monsoon season compared to the dry season. While dietary diversity and lost work due to weather were identified as pathways affecting food security, child illness was not found to be a significant mechanism contributing to seasonal nutritional declines.

Bernard Keraita, Pay Drechsel, Flemming Konradsen · Journal of Risk Research · Ghana

A study in Ghana used participatory research methods to summarize farmers' perceptions of health risks and risk reduction measures in urban vegetable farming irrigated with untreated wastewater. Farmers were aware of health risks from wastewater, perceiving occupational skin infections as the greatest risk, while consumer health risks were rated very low. Many international risk reduction measures were deemed unsuitable by farmers, who preferred simple, low-cost alternatives.

Tamara García–Armisen, Josué Prats, Yociel Marrero, Pierre Servais · Water Science & Technology · Cuba (Havana)

The Almendares River in Havana, Cuba, receives wastewater from over 200,000 inhabitants, resulting in very poor microbiological water quality downstream due to high faecal bacterial indicators (FBIs). This water is used for urban agriculture and recreation, despite not meeting microbiological standards. This study compared FBI removal in three wastewater treatment plants (WWTPs): a conventional facility, a constructed wetland (CW), and a solar aquatic system (SAS). Natural systems (CW and SAS) showed approximately two log units higher FBI removal efficiency than the conventional plant. The large conventional WWTP was found to have a negative impact on the river's microbiological quality.

J.N. Hogard, Julius N. Fobil, Godfred K. Ofosu-Budu, D. Carboo, Nii‐Ayi Ankrah, Alexander K. Nyarko · · Ghana

This study in Ghana investigated the macro-nutrient content and heavy metal concentrations in solid waste composts to assess their potential for soil fertility amelioration and health implications in urban and peri-urban agriculture. Overall NPK concentration was low, with agricultural waste composts showing higher total N, K, and organic carbon than municipal solid waste (MSW) composts. Heavy metal concentrations for Ni, Zn, Cu, and Cd were generally low and within Australian standards. However, lead (Pb) concentration in mixed MSW composts was significantly high during the dry season, exceeding the Australian limit of 150 mg/kg Pb for unrestricted use. Seasons and composting processes were found to be important determinants of toxic metal concentrations in final compost products.

Bernard Keraita, Pay Drechsel, Flemming Konradsen · Water Science & Technology · Ghana (Kumasi)

A study in Kumasi, Ghana, assessed the use of on-farm ponds to reduce microbial contamination in wastewater-contaminated irrigation water, analyzing over 300 samples. It found that while ponds are common, their potential for pathogen removal via sedimentation is not fully optimized. Helminth eggs reduced by about 70% with careful water collection, but thermotolerant coliforms took six days in the dry season to meet WHO guidelines, indicating suboptimal performance for some pathogens.

Pay Drechsel, Olufunke Cofie, R. van Veenhuizen, Theophilus O. Larbi · Irrigation and Drainage · West Africa

Informal irrigation in urban and peri-urban agriculture (UPA) in West Africa offers benefits but is often hindered by water pollution, threatening public health. A multi-stakeholder process implemented since 2005 in six West African cities, including Accra, Ghana, aimed to integrate UPA into sustainable urban development. However, an internal lesson learned was that local partners may not prioritize every project, and capacity-building efforts might not provide expected incentives for commitment.

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.

M. B. David · African Affairs · Kenya

This study on urban agriculture in the Kenyan town of Nakuru illustrates health and environmental problems associated with keeping livestock in urban areas, the small size of plots cultivated, and the dependence of urban households on rural sources of food. These findings were observed in the context of economic hardships occasioned by structural adjustment programmes since the 1980s.

Dorothy Blair · The Journal of Environmental Education · United States

An evaluative review of U.S. literature on children's gardening found that quantitative studies showed positive outcomes in science achievement and food behavior. However, these studies did not consistently demonstrate improvements in children's environmental attitude or social behavior, and validity and reliability issues reduced general confidence in the results. Qualitative studies documented a wider range of desirable outcomes, but teacher enthusiasm varied based on support and horticultural confidence.

Evan Green · · United States (California)

A literature meta-analysis on lead contamination in urban farms was applied to Alemany Farm in San Francisco, California, where soil lead concentrations range from 60 to 720 ppm. It found that every food crop except tree fruits may pose a health risk if grown in Alemany Farm's soil. A phytoremediation plan using Indian mustard (Brassica juncea) to remove lead was found to exceed the farm's available budget, and its timescale made it impractical. The study concludes that phytoremediation is generally not feasible for small-scale urban farms and that other measures are needed to reduce lead exposure for urban farmers.

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.