Research & reports

Bernard Keraita, Pay Drechsel, Philip Amoah · Environment and Urbanization · Ghana (Kumasi)

This study in Kumasi, Ghana, investigated the influence of urban wastewater on stream water quality and peri-urban agriculture through interviews and water quality assessments. It found that population increase and underinvestment in sanitation facilities led to large volumes of untreated wastewater entering streams. High levels of faecal coliform were recorded in the city's streams, downstream areas, and on vegetables sold in Kumasi’s markets due to contaminated wastewater.

Jeroen H. J. Ensink, Wim van der Hoek, Yutaka Matsuno, Sarfraz Munir, Muhammad Rizwan Aslam · CGSPace A Repository of Agricultural Research Outputs (Consultative Group for International Agricultural Research) · Pakistan

The use of untreated wastewater for irrigation is widespread in Pakistan's peri-urban agriculture, driven by water scarcity and lack of treatment funds. This practice has led to an uncontrolled expansion of wastewater use. The paper emphasizes the need to document this practice to find improvement methods within the financial constraints of low-income countries.

Guéladio Cissé · Infoscience (Ecole Polytechnique Fédérale de Lausanne) · Burkina Faso (Ouagadougou)

This thesis investigates the sanitary risks of using polluted water for urban agriculture in Ouagadougou, Burkina Faso, where vegetables, including those eaten uncooked, are irrigated with such water. The study aims to assess diarrhoea incidence, parasitic infection prevalence, microbiological pollution levels in water, soil, and vegetables, and sociocultural factors. Initial findings indicate that peripheral sectors are more polluted than central ones, and exploited surfaces vary significantly by season. The abstract highlights potential sanitary risks due to pathogenic germs surviving in water, soil, and plants.

James R. Preer, Ahmed N. Abdi, Harkewal S. Sekhon, George B. Murchison · Journal of Environmental Science and Health Part A Environmental Science and Engineering and Toxicology · Global

This study investigated cadmium (Cd) and zinc (Zn) concentrations in vegetables grown in community gardens on different urban soils. Vegetables from a low-pH urban soil without contamination history showed higher Cd and Zn levels than those from a reclaimed landfill with digested sewage sludge, and also higher than a low-metal, neutral-pH site. Liming on the low-pH site reduced Cd and Zn concentrations in beet, lettuce, radish, and Swiss chard leaves, reaching background levels after four years. The findings indicate that soil pH is more important than total soil Cd and Zn in determining vegetable metal availability.