In order to protect and improve market garden crops, market gardeners use large quantities of plant protection products and water in the production area. This has an impact on soil quality. The aim of this study was to determine the level of soil pollution downstream of the Daloa Regional Hospital. Twenty-four soil samples were taken from six sites in the study area. These samples were analysed by liquid/liquid chromatography coupled with mass spectrophotometry.
The results of the analyses revealed the presence of seven medicinal residues, including five antibiotics (Ciprofloxacin, Erythromycin, Tetracycline, Sulfamethoxazole and Norfloxacin), a beta-blocker (Propranolol) and an anti-inflammatory (Salicylic Acid). The average concentrations of these antibiotic residues ranged from 3.41 to 50.34 µg/kg; the anti-inflammatory and the beta-blocker recorded values of 112.67 µg/kg and 17.35 µg/kg respectively. Eleven residues of active ingredients, including Chlorothalonil, Cypermethrin, Metamidophos, Endrin, Deltamethrin, Dimethomorph, Profenofos, Beta-endosulfan, Etoenprox, Furathiocarb and Carbendazim, were quantified at levels ranging from 0.04 to 39.62 µg/kg. These active ingredients belong to five families of plant protection products: organochlorines, organophosphates, carbamates, thiocarbamates and synthetic pyrethroids. The constant discharge of these medicinal and phytosanitary residues contaminates the soil and poses a threat to humans and their environment.