No abstract

This study is carried out to characterize the CHU-MEL effluents discharged into the Cotonou lagoon to assess the potential hazards of these releases for this ecosystem. To achieve this goal, the effluents collected at the end of the spillways have been analyzed. The results obtained from the physicochemical and microbiological analysis made it possible to assess the quality of the effluents. The pH, temperature and conductivity measured in-situ are, on average, 6.65, 30.3 °C and 763 μS/Cm. The average contents of dissolved oxygen, nitrite, nitrate, ammonium and Nitrogen Total Kjedhal (NTK) are respectively 1.

Health-risk market garden production linked to heavy metals in irrigation water in Benin Production maraı ˆche`re a `risques lie´s aux me´taux toxiques dans l'eau d'irrigation au Be´nin

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 with Zeeman 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.

According certain studies, smoking could be associated with an increase of health risk link to heavy metals and these risks would be more important in developed countries. So, this study attempted to verify these informations throuth the comparison of the levels of lead (Pb), cadmium (Cd) nickel (Ni) and arsenic (As) in some cigarettes sold in Benin and France. Composite samples of cigarette brands purchased in Benin (developing country) and France have been taken in the same periods from the two countries. Samples were analyzed for cadmium (Cd), lead (Pb), nickel (Ni) and arsenic (As) by atomic absorption spectrophotometer. The amounts (average ± SD) have been compared by the statistical Student p test (T>t) = 0.05. The results showed that all the cigarettes tobacco is differently contaminated with Cd, Pb, Ni and As. The amounts reveal that for all metals the regulatory limits are over passed but the level of contamination varies from one brand to another one. However, it could not be obvious to conclude that the cigarettes in developed countries are more concentrated in heavy metals than those of developing countries. This affirmation has been discussed. Indeed, it appeared that the level of lead and arsenic obtained in some cigarette brands purchased in Benin were significantly higher than (p<0.05) those sold in France. Otherwise, all the France cigarette brands contain about two or three times more cadmium that Beninese cigarettes. However, excepted these particularities, there was no significant differences (p<0.05) between heavy metals contents in cigarette brands sold in Benin and France. Overall, findings from this study suggest that, Beninese cigarettes did not differ in heavy metals contents from cigarettes sold in France markets. The high levels of toxic metals recorded in some cigarette tobacco from each country are probably the result of soil conditions where tobacco is grown. But, the presence of high levels of heavy metals may constitute a global health concern. The adoption of reasonable behavior are needed to preserve the public health.