Pesticide contamination of water used for urban market gardening in Bamako (Mali)

The use of natural and synthetic pesticides is increasingly common in developing countries, particularly in pest control efforts to improve crop yields. Misuse of these plant protection products can lead to a loss of efficacy on crops and the development of certain diseases. Among the most widely used insecticides in the world, pyre-throids are generally very fast acting against all insects but are also very toxic to the aquatic environment. In Mali, there are few studies on the risks of these phytosanitary products for market gardening on the health of rural populations and on the environment. It is in this context that we are conducting our research on phyto-sanitary products intended for various vegetable crops. The objective is to determine the level of pesticide contamination of water used for urban market gardening in Bamako, particularly by pyrethroids. In order to carry out these analyses, we collected water from wells, boreholes, marigots and the Niger River during the dry season and in winter. We chose a solid phase extraction (SPE) for the active substances present in the water. For their separation, we used an Ultra Performance Liquid Chromatography (UPLC) chromatograph, which allows a single separation for the active substances present in the water. The analytical results show the presence of cypermethrin residues. Market gardening uses a large quantity of synthetic pesticides, but there is a change in practice with the use of biopesticides, which would eventually reduce the risks for the environment and the health of the applicators.