Physico-chemical and bacteriological quality of groundwater in a rural area of Western Niger: a case study of Bonkoukou.

The precariousness of the rural population in Africa is often symbolized by the lack of potable and safe drinking water. This study investigates the physico-chemical and bacteriological characteristics of 32 water samples with respect to WHO standards. The water samples were collected from wells, boreholes and small drinking water supply systems (DWS) in and around the township of Bonkoukou (Niger). The Water Quality Index (WQI) tool was used to assess the overall water quality with different physico-chemical parameters. Where the pH of the samples was acceptable, the samples showed higher levels of mineralization and deoxygenation. Overall, the samples were slightly hard, chlorinated and sulfated but much alkaline and contained nitrate and nitrite ions 2-16 times higher than the WHO standards. The use of WQI shows that samples in the DWS are safe for drinking. Samples coming from wells are the most polluted (58.50%) compared to those taken from boreholes (53.00%), while the percentage of samples from boreholes, unfit for drinking, is higher (41.00%) than that of the samples taken from wells (25.00%). Moreover, water in this area was characterized by the presence of total germs indicating bacteriological pollution. Hence, for the supply of safe drinking water to the larger number of people in such a rural area, the capacity of actual DWS must be improved and widespread.

Techno-economic data for decentralised energy system sizing for rural areas in Benin. A case study of the village of Fouay.

This data article is related to the research article "O.D.T. Odou, R. Bhandari, R. Adamou, Hybrid off-grid renewable power system for sustainable rural electrification in Benin, Renew. Energy. 145 (2020) 1266-1279. doi:10.1016/j.renene.2019.06.032.''. The data presented are grouped into four (04) groups as follows: Load, Ressources, Components costs and specification and Optimization and Simulation data. The data are mainly acquired from onsite survey for the load demand, National Direction of Water (DGeau) for rivers streamflow, National Direction of Meteorology (DNM) for meteorological data, expert knowledge and HOMER software model output data. An empirical method is used to estimate the river streamflow at Fouay from the known gauged streamflow data. The purpose of this article is to make available reliable open access data to allow replicability and enhance research in similar studies while giving first-hand information to users.

Exposure assessment of operators to pesticides in Kongou, a sub-watershed of Niger River valley.

The use of pesticides in horticultural sector in Niger has become an integral part of modern agriculture. Nevertheless, their inappropriate use can generate negative health effects to operators. A study was carried out among Kongou farmers in order to assess their potential dermal exposure (PDE). The UK-POEM model was used to quantify the PDE during mixing/loading and application according to the local practices. In order to determine which parts of the operator body are subject to most contamination during spraying and to validate the theoretical model used, a patch method was used with a tartrazine dye. The deposits of the tartrazine on patches were measured by colorimetry thanks to the absorbance value determined after their extraction in water and a calibration curve. A total of ten spraying trials (five trials with the hand-held sprayer and five others with the backpack sprayer) were performed by different producers at 0.5 and 1 m height for each trial. The survey shows that 92% of the farmers are illiterate and the most common active substances identified are organophosphate or pyrethroids insecticides. Seventy percent of operators do not use any personal protective equipment (PPE) during mixing/loading or spraying. The predictive systemic exposure levels vary from 0.0027 mg kg-1 bw per day to 0.7692 mg kg-1 bw per day for backpack sprayer and from 0.0261 mg kg-1 bw per day to 0.9788 mg kg-1 bw per day for hand-held sprayer, several times higher the Acceptable Operator Exposure Level (AOEL) for some actives substances. Theoretical modeling indicates more exposure of operator by a hand-held sprayer than a backpack sprayer. The patch method results show that the deposits of dye increase when the position of sprayer nozzle increases from 0.5 to 1 m for the two sprayers. All parts of the operator body are contaminated but lower body parts and chest are the most exposed. The patch method results also show that hand spraying contaminates operator more than backpack spraying, confirming the results of the theoretical model.

Photochemically-induced fluorescence dosage of non-fluorescent pyrethroid (Etofenprox) in natural water using a cationic micellar medium.

An analytical method based on the use of UV-irradiation to produce fluorescent derivatives from Etofenprox a non-fluorescent pyrethroid insecticide is described. The impact of cetyltrimethylammonium chloride (CTAC) micellar medium on the Etofenprox photochemically-induced fluorescence (PIF) is reported. Parameters influencing the sensitivity and repeatability of the PIF method have been optimized. The alkaline medium (NaOH 6 × 10(-2) M) + CTAC surfactant molecules (3.84 mg/ml) in acetonitrile is found to be very suitable for this pyrethroid insecticide analysis in environment matrices. Linear dynamic range is established over more than two orders of magnitude. The limit of detection is lower than 5 ng/ml. The method seems to be suitable for environmental matrices quality control. Application to the analysis of spiked natural waters gave recoveries rate ranged from 94 to 104% and 107 to 115% respectively for river and pound water.

Fluorimetric determination of histamine in fish using micellar media and fluorescamine as labelling reagent.

An analytical method based on the use of fluorescamine to produce a fluorescent derivative with histamine and combined with micellar-enhanced fluorescence detection of the formed complex is developed for the sensitive and rapid determination of histamine in fishes. The fluorescence properties of the obtained complex in water and micellar solutions of sodium dodecyl sulfate (SDS), cetyltrimethylammonium chloride (CTAC) and brij-700 are reported. Physicochemical variables influencing the sensitivity of the method (pH, micellar, fluorescamine and NaCl relative concentrations) have been optimized. The stability of the formed complex, as shown by kinetic study, depends on the pH of the solution. Linear calibration curves allowing an effective histamine determination were established with large linear dynamic range (LDR), and low limits of detection (LOD) between 0.5 and 33 ng mL-1, according to the solvent. Application to the analysis of fish samples (sardines) yielded satisfactory results. The method seems to be suitable for environmental fish quality control.