Untreated wastewater use in market gardens: a case study of Dakar, Senegal.

Abstract

Urban vegetable production in Dakar plays a significant role in fighting poverty, as it provides both income to farmers, and a source of nutritious food for the poor. However, the irrigation of these crops is cause for concern, as many farmers prefer untreated wastewater to freshwater due to the higher profits stemming from its greater availability, reduced fertiliser costs, and higher yields and production. While using such water, few take precautions to protect their health, and 60% are infected with intestinal parasites. The practice also poses a risk to public health, as three of the main crops produced (lettuce, tomatoes, and onions) are often or exclusively eaten raw. Thus, while there is a growing willingness among policymakers to encourage urban agriculture (UA), there is also the recognition that current irrigation practices are unsafe. Authorities looking to decentralise wastewater treatment need reassurance that community-level systems can be proven efficient and sustainable. It is recommended that action research be conducted that includes finding effective treatment systems, and that tests the feasibility of other management options such as increasing public awareness, using safer irrigation methods, and practising restricted irrigation. Additional research on the economic importance of UA is also necessary to encourage donors to fund research and development initiatives. Ultimately, action must be taken soon, or a repeat of the 1987 typhoid epidemic in Dakar could lead to backlash among consumers and policy-makers, with devastating consequences for both poor farmers and poor consumers.

Concentrations of Heavy Metals and Pesticide Residues in Leafy Vegetables and Implications for Peri-urban Farming in Nairobi, Kenya

“…Some studies show an association between exposure to pesticides and health problems such as cancer, attention deficit (hyperactivity) disorder, and nervous system disorders, and suggest that exposure to pesticides could weaken the immune system (Faruqui, Niang, & Redwood, 2004;Kakar et al, 2006;Karanja et al, 2010). In this study, we explore pesticide bioaccumulation in the leafy vegetable kale that is grown in peri-urban areas of Nairobi.…”

Effect of Alkaline Stabilized Domestic Wastewater on Soil Properties and Yield, Quality and Nutrition of Silage Maize

“…Research and experience have shown that domestic wastewater or biosolids can be beneficial both as soil conditioners and as a source of nutrients (Rosenqvist et al, 1997;Faruqui et al, 2002;Tamoutsidis et al, 2002). When biosolids are stabilized by high lime treatment, they can also have some value as a liming material for acidic soils and can substitute for agricultural lime (Jacobs and McCreary, 2001;El-Naim et al, 2004).…”

Managing wastewater agriculture to improve livelihoods and environmental quality in poor countries

“…In Nairobi, where irrigated production continues through the whole year, average annual family income generated from mostly wastewater irrigated agriculture was USD 279 (Cornish and Lawrence, 2001). Urban farmers in Dakar indicated that they earned USD 2234 annually (Faruqui et al, 2004). Likewise in Ghana, irrigated wastewater farming generated incomes ranging from USD 500-700 to 2000-8000 annually (depending on crop type and cropping intensity) that enabled these farmers to leap over the poverty line (at the time of study, approximately…”