Contamination of boreholes water by 76 pesticides molecules in the cotton zone of Kérou

Analysis campaign of underground water was done in 2010 on five boreholes water samples situated in agricultural cotton zone. The obtained results showed the presence of various active matters of at least 76 residues of pesticides, especially insecticides, herbicides and fungicides, with accumulated contents which could average 0.350 or 350 ƒÊg/L per borehole. Indeed, all the prospected boreholes were contaminated. Every molecules of pesticides analyzed were present with at least 1 ƒÊg/L, some molecules concentration such as: aldrine (7 } 0.7 ƒÊg/L), dieldrin (2 } 0.7 ƒÊg/Ls), phorate (7 } 2 ƒÊg/L) and terbufos (7 } 1 ƒÊg/L), highly exceeded maximum residue limits. The most affected zones of the contamination of the underground water by pesticides were those areas where the cotton faming is practiced.Keywords: Kerou, cotton farming, water of boreholes, pesticides

Evaluation de la contamination des eaux du fleuve Couffo dans la zone cotonnière de Djidja (Bénin) par les pesticides

Dans la commune de Djidja, les champs de coton et autres cultures sont parfois installés non loin des berges des cours d’eau et sont souvent traités avec des pesticides. L’objectif de ce travail est d’évaluer le niveau de contamination des eaux du fleuve Couffo par les pesticides dans la commune de Djidja. Neuf (09) échantillons d’eau ont été prélevés en neuf (09) points le long du fleuve. L’analyse de ces échantillons a été faite par chromatographie en phase gazeuse après extraction et purification. Les résultats montrent une contamination des eaux par le glysophate qui varie entre 0,193 et 0,105 μg/l, par le profénofos variant entre 0,095 et 0,128 μg/l, par l’acétamipride qui varie entre 0,043 et 0,082 μg/l et par la cyperméthrine variant entre 0,096 et 0,133 μg/l. Un programme de surveillance régulière doit être établi afin de limiter au mieux la contamination de ces eaux par les pesticides.Mots clés: Djidja, pesticides, coton, eau, contamination

Assessment of groundwater to pollution by the toxic metals in the municipality of Kerou (Benin) in watershed of the Niger

This case study has assessed the vulnerability of boreholes water to pollution by toxic metals in the cotton zone of Kerou, in northern Benin. Toxic metals (lead, copper, cadmium, zinc, nickel and iron) were analyzed by atomic absorption spectrophotometry. The results show high values for lead, nickel and iron, which means that 7 out of 18 boreholes are contaminated. Only the lead level exceeds the standard for the boreholes of Ganbore and Korigourou (0.0613 and 0.098 mg/l against 0.04 mg/l) The level of contamination of Cadmium, zinc and copper is very irregular, but however one must notice that the two aforementioned boreholes are contaminate with the concentration of cadmium above the permitted limit (0.0234 and 0.0244 mg/l against 0.005 mg/l). These findings allow us to say that, apart from the two boreholes of the localities of Ganbore and Korigourou located in cotton farm, most of the boreholes are resistant to pollution. So the responsible factors, of the noticed contamination are defined. It is above all due to the cultivation of cotton in this area. The assays witness of the Mekrou River has revealed high contamination by lead (0.060 mg/l) and the iron (1.4341 mg/l): this result can highlight the ongoing relationship of surface water with groundwater.Keywords: Vulnerability, groundwater, contamination, toxic metals, cotton cultur

Assessment of pesticides residues in fish (Tilapia guineensis) in the Couffo River in Djidja (Benin)

In Benin, the main cash crop is the cotton of which the level of production is largely insufficient to satisfy the national and International market. The main food crops (corn, cassava, yam, bean, rice, etc.) permit to cover the food needed globally, but remain again extensively on this side of the potentialities offered by the ecological conditions of the country. In the process to increase the agricultural production, the herbicides, insecticides and the fertilizers are used now in higher quantity that in the past. The aim of this work was to assess the level of contamination of fish (Tilapia guineensis) in the Couffo River in Djidja (Benin) by the pesticides. Nine (09) samples of fish (Tilapia guineensis) have been collected in nine (09) points along the Couffo River. The analysis of these fish has been done by gas chromatography after extraction and purification. In fish, the detected concentrations in average ranged between 0.123 µg/kg and 0.191 µg/kg for the glyphosate, from 0.095 to 0.128 µg/kg for the profenofos, between 0.112 and 0.125 µg/kg for the acetamiprid and 0.127 and 0.139 µg/kg. To assess the risk to public health, pesticides intake by fish consumption was estimated and compared with Estimated Daily Intake (EDI) values reported by the Codex Alimentarius. This comparison showed that fish consumption does not pose a risk for public health

Pesticides et métaux lourds dans l’eau de boisson, les sols et les sédiments de la ceinture cotonnière de Gogounou, Kandi et Banikoara (Bénin)

Dans cette expérimentation, nous avons évalué la contamination de l’eau de boisson, du sol et des sédiments par les métaux lourds et les pesticides liés à la culture du coton dans la zone cotonnière de Gogounou, Kandi et Banikoara (Bénin). Les résidus de pesticides (pyréthrinoïdes, insecticides et organophosphorés) sont recherchés par chromatographie en phase gazeuse ; les métaux lourds (cadmium, plomb, arsenic, nickel, zinc et mercure), par spectrophotométrie d’absorption atomique. Les résultats ont montré dans les trois régions une contamination régulière de l’eau de pompe par les métaux à l’exception du mercure (0.000 ppb) et de l’arsenic (0.000 ppb). Les teneurs les plus élevées avoisinent 0,126 ppb et 0,100 ppb respectivement pour le plomb et le zinc. Pour les pesticides, la contamination est aussi régulière pour chaque matière active au sein d’une même famille de pesticides. Les teneurs en cyfluthrine des pyréthrinoïdes tournent autour de 0,200 ppm dans les sédiments et celles de l’endosulfan des organophosphorés, autour de 0,080 ppm dans tous les sols. Mais les concentrations de métaux lourds et de pesticides sont plus élevées dans les sédiments que dans les sols.© 2010 International Formulae Group. All rights reserved.Mots clés : Culture cotonnière, sol, eau de pompe, sédiments, métaux lourds, pesticides

Preliminary assessment of the contamination of the marine water and fish by trace metals in Cotonou (Benin)

Facing the problem of the pollution of the watery ecosystems world-wide, a preliminary assessment of the contamination of marine environment was performed on samples of water and fish coming from the Atlantic Ocean on the coasts of Cotonou. Aluminium (Al), cadmium (Cd), chromium (Cr), copper (Cu) and lead (Pb) were quantified by electrochemicalatomic absorption spectrophotometer (Varian A300), in the Laboratory of Toxicology and Applied Hygiene /UFR of the Pharmaceutical Sciences (Bordeaux-France). Results show that acceptable limits are exceeded for cadmium and chromium in the fish. Aluminium, lead and copper should nevertheless be supervised. These findings evidence of the pollutionof the marine environment by toxic metals along the Benin. This survey also permits us to conclude some fish, so important in the food of the populations of Benin, are unfortunately unfit to the consumption and therefore, would be to the origin of human health problems.Keywords : Benin, marine pollution, toxic metals, fish quality

An assessment of the contamination of Achatina achatina by toxic metals in Okpara village (Benin)

The assessment of the contamination by toxic metals (Pb, Al, Cd, Cu, Cr, Zn, Mn) has been achieved in samples of the giant snails (Achatina achatina) in the Okpara village (North of Benin). This work has been performed for, lately a survey revealed a strong contamination by toxic metals in sediments, water and fish in the Okpara River which waters this village. Otherwise, it is in this environment watered by the Okpara River,that snails are picked and consumed. The appropriated samples underwent the necessary treatment by mineralization before the analysis by electrochemical atomic absorption spectrophotometer (Varian A300 withZeeman correction), in the Laboratory of Toxicology and Applied Hygiene/UFR of the Pharmaceutical Sciences (Bordeaux-France). The results of the analysis revealed a high bioaccumulation of heavy metals in all the samples and the concentrations exceed the recommended limits for human consumption. Only the level of chromium respects the recommended limits. This study permitted us to confirm as it has already proved by several authors, that the snail is a toxic metal bioaccumulator and can be considered therefore like a bioindicator of pollution, whose consumption will be a risk for health.Keywords: Environment pollution, snail quality, bioaccumulation, consumption risk

Sanitary Risks Connected to the Consumption of Infusion from Senna rotundifolia L. Contaminated with Lead and Cadmium in Cotonou (Benin)

This study carried out an assessment of sanitary risks connected to the consumption of Senna rotundifolia Linn. contaminated with lead and cadmium. This plant was collected and analyzed by atomic absorption spectrophotometry. The results revealed a contamination of plants from markets of Dantokpa, Vossa, and Godomey with heavy metals. Senna from Vossa was higher in cadmium and lead levels (Pb: 2.733 mg/kg ± 0.356 mg/kg; Cd: 0.58 mg/kg ± 0.044 mg/kg) compared to the two other places (Pb: 1.825 mg/kg ± 0.133 mg/kg, Cd: 0.062 mg/kg ± 0.015 mg/kg and Pb: 1.902 mg/kg ± 0.265 mg/kg, Cd: 0.328 mg/kg ± 0.024 mg/kg), respectively, for Dantokpa and Godomey. In terms of risk assessment through the consumption of Senna, the values recorded for lead were nine times higher with children and six times higher with adults than the daily permissive intake (Pb: 3.376 × 10−2 mg/kg/day for children and 2.105 × 10−2 mg/kg/day for adults versus 3.6 × 10−3 mg/kg/day for DPI). With respect to cadmium, there was no significant difference between the recorded values and the DPI (Cd: 1 × 14 10−3 mg/ kg/day for children and Cd: 0.71 × 10−3 mg/ kg/day for adults versus Cd: 1 × 10−3 mg/kg/day for adults). This exposure of the population to lead and cadmium through the consumption of antimalarial healing plants could pose public health problems