The study was conducted to monitor the concentration of pesticide residues in three staple vegetables (tomato, cabbage, lettuce) collected from 12 prefectures belonging to 4 agro-ecological regions of Togo. A total of 150 samples of ripe tomato, cabbage and lettuce were collected from the study areas and analyzed for 20 OCPs (organochlorine pesticides) residues, which can be grouped into DDTs, Drins, Heptachlors, Chlordanes and HCHs. The data revealed that 100% of the analyzed vegetable samples were contaminated by one or more pesticide residues; 83.32% and 100% were below the maximum residue limits (MRLs) set par European Union and FAO/WHO respectively whereas 16.68% were above the EU (MRLs) adopted values. Overall, cabbage contained the highest number of samples with pesticide residues above the MRLs followed by tomato, whilst none of lettuce samples contained pesticide residues above the MRLs. It is therefore proposed to perform continuous monitoring studies of pesticide residues in vegetables cultivated in Togo.

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Région des Plateaux in Togo is the highest producer of cash crops (coffee, cocoa, cotton) as well as vegetables. This region is the area with the supreme use of chemical pesticides to enhance agricultural production in Togo (west Africa). As effective as these chemicals may be in achieving this goal, the incidence of their residues on the environment, together with the associated adverse effects, have been of serious concerns. The objective of this study is to assess soils contamination by organochlorine pesticides in vegetable production areas within this region. Fifty-four soil samples were randomly collected from selected farmers' plots within six villages. The analytical methods included solvent extraction of pesticide residues and their subsequent quantification using gas chromatography -electron capture detector (GC-ECD). Twenty one different organochlorine pesticides were analyzed. The analytical results showed that only aldrin, endosulfan (α-, β-and sulfate), and hexachlorocyclohexanes (HCH) isomers, including α-HCH, β-HCH, δ-HCH and γ-HCH were detected in various concentrations. The residuals of aldrin varied from detection limit (DL) (< 0.001 µg/kg) to 0.93 ± 0.03 µg/kg, the concentrations of α-endosulfan from DL to 1.88 ± 0.41 µg/kg, β-endosulfan from DL to 0.4 ± 0.01 µg/kg and endosulfan sulfate from DL to 3.87 ± 0.19 µg/kg. On the other hand the concentration of each isomer of HCH ranged from DL to 0.89 ± 0.07 µg/kg (α-HCH), 14.6 ± 0.12 µg/kg (β-HCH), 4.27 ± 0.61 µg/kg (γ-HCH) and 2.92 ± 0.05 µg/kg (δ-HCH). The pesticide residue concentrations found in the studied soils were highly below maximum residue limits varying from 100 to 8000 µg/kg set by Food and Agriculture Organization of the United Nations (FAO). The detected pesticide residues reflected the type of pesticides that have been used in the study areas. The differences in the concentrations of these pesticide residues in the soil samples are likely the result of substantial inter-farm variation in intensive use of pesticide as well as the variation in their degradation dynamics. The findings of this study provide information on residue levels of organochlorine pesticides in soils from "Région des Plateaux" in Togo. Routine monitoring of pesticide residues in these study areas is necessary for the prevention, control and reduction of environmental pollution, leading to minimize health risks.Palabras clave: oeste de África, producción vegetal, contaminaciónRev. Int. Contam. Ambie. 33 (Especial Biotecnología e ingeniería ambiental) 33-42, 2017 DOI: 10.20937/RICA.2017.33.esp01.03 L. Kolani et al. 34 RESUMENLa región "des Plateaux" en Togo es una de las más grandes productoras de cultivos comercials (café, cocoa, algodón), así como también de verduras. Esta región es el área con el mayor uso de pesticidas químicos para mejorar la producción de la agricultura en Togo (oeste de África). Así como son de efectivos estos químicos, la incidencia de sus residuos en el ambiente también lo es, al igual que los efectos adversos asociados a ellos, ...

Camarero Simon A. (1997). The influence of solid urban waste compost and nitrogen -mineral fertilizer on grow the and productivity in patatoes. Commun. Soil. Sci.Plant anal., 28, pp: 1653-

This study was carried out to evaluate the contamination severity of Lake Togo by organochlorinated pesticides historically used in agriculture and in health programs against disease vectors in public health. A total of 48 samples of sediments and 48 samples of water were seasonally collected. For both sediment and water 3 samples per site were collected at 8 sites in the 2014 rainy season and in the 2015 dry season. Water samples were processed using a liquid-liquid method solvent extraction while Soxhlet extraction was used for sediment samples. The sediment and water extractions were cleaned-up and qualitative-quantitative analysis performed on gas chromatograph equipped with electron capture detector (GC-ECD). Pesticides residue levels in water ranged from < 0.001 to 0.093±0.20 µg l-1 (lindane) in rainy season and from < 0.001 to 0.352±0.07 µg l-1 (dieldrin) in dry season. They were lower than that found in sediment which ranged from < 0.001 to 0.98±0.18 µg kg-1 dry weight (pp′-DDE) in rainy season and from < 0.001 to 2.19±0.31 µg kg-1 dry weight (heptachlor epoxide) in dry season. The concentrations of the organochlorinated residues in water and sediment were higher during the dry season. Except pp′-DDE, pp′-DDD, heptachlor and heptachlor epoxide, the others pesticide residues concentrations detected in water samples in dry season were above the maximum acceptable concentration of 0.1 µg l-1 for individual pesticides set by the European Union (EU) for the protection of human health. Pesticide contamination level of Lake Togo is therefore, likely to be harmful to human health in dry season.