Human Health Risks from Exposure to Heavy Metals of Suspended Particulate Matter around the Tongon Gold Mine, Côte d’Ivoire

The Tongon mine, the largest gold mine in C?te d’Ivoire, has been in operation since April 2010. However, to our knowledge to date, no study has been conducted on metallic contamination in suspended particulate matter (PM10 and PM2.5) where there is a lack of information on the carcinogenic and non-carcinogenic risk to human health associated with the exposure of populations in the Tongon area to these pollutants. The general objective of this study is to evaluate the level of contamination of PM10;PM2.5 by heavy metals and their impact on the health of populations exposed to these pollutants in the Tongon gold mine area. The sampling and measurement of suspended particulate matter (PM10 and PM2.5) were done using a MiniVol TAS passive air sampler. Heavy metal concentrations were determined by inductively coupled plasma mass spectroscopy (Nex ION 2000 ICP-MS, USA). The results indicate that the average concentrations of suspended particles (PM2.5 and PM10) obtained are all above the recommended exposure limits. In addition, among the heavy metals contained in the suspended particles, the concentrations of arsenic and nickel are high and all above the standard limit values. The assessment of the health risks related to the inhalation of PM10 particles reveals that their inhalation over a long period could cause a carcinogenic risk.

Problem of the Profitability of Irrigated Agriculture in the Sahel Environment: Case of Producers of the Konni Hydro-Agricultural Development

In Niger, a poor and arid country in West Africa, irrigated agriculture is undoubtedly the means with the greatest chance of ensuring food and nutritional security, increasing incomes and therefore reducing poverty, especially in rural areas. This research aims to analyze the profitability of irrigated agriculture at the level of the hydro-agricultural development of Konni. The methodological approach adopted is based on the method of “Rapid Participatory Diagnosis and Planning of actions to improve the performance of irrigated perimeters (DPRP)”. The documentary research made it possible to capitalize on the information available on the question. The collection of primary data in the field was carried out using questionnaires and interview guides submitted to actors directly or indirectly involved in the management of Konni’s AHA, taken individually or in focus group discussions. The data collected was processed with SPSS software to be analyzed and graphically illustrated with the Excel spreadsheet. The performance analysis made it possible to identify yields and constraints to the development of irrigated agriculture. The results show that on the Konni perimeter, there is a general trend towards a reduction in areas both in SS and in SH, with higher development rates in SH (80% to 90%), whereas they are very low in SS (8% to 25%). The main crops favored by Konni producers are onions, tomatoes, cabbage, corn and sorghum. Onion and tomato crops are more important sources of income than dune crops. In this context, the main challenges to be met for a better profitability of irrigated agriculture concern the socio-economic context of production, insufficient financing of infrastructures and their maintenance, small areas often below the break-even point, environmental degradation.

Assessment of Soil Contamination and Human Health Risk around an Industrial Gold Mine in Côte d’Ivoire: The Case of Arsenic

The Tongon mine generates millions of tons of waste rock and tailings, which are stored in landfills in the vicinity of the mine. These tailings contain arsenic. The risk of soil contamination in this area is evident. This study assesses the arsenic contamination of soils around the mine and the health risks to the local population. Soil samples were taken from plastic bags and other materials used as working tools. Arsenic concentrations were determined by inductively coupled plasma mass spectroscopy, after the soil samples had been concentrated and digested. Metal contamination indices were used to assess the degree of soil contamination. The results obtained indicate that soils in the industrial zone of the Tongon gold mine have very high average concentrations, well above the world average for uncontaminated soils of 6 mg/kg arsenic. Geoaccumulation index values range from 1.28 to 3.40. These values highlight severe arsenic soil contamination. The human health risk assessment revealed that exposure risks are well above the critical limit of 1 and are, in descending order, children > adult women > adult men. These results indicate an ecological risk, requiring environmental monitoring, underpinned by the development of an effective remediation strategy to reduce local pollution and contamination.

Stratigraphic Data and Groundwater Resources in the Coastal Sedimentary Basin of the Pointe-Noire Region (Republic of Congo)

The synthesis of geological and petroleum research undertaken in the coastal Sedimentary Basin of the Pointe-Noire region enabled the establishment of a lithostratigraphic scale. It has been observed that the order in which the series observed in outcrop and those encountered by deep wells succeed each other has allowed a value to be given to this relative scale. The study area corresponds to a longitudinal tectonic accident, fault or flexure. It belongs to the Cretaceous and Tertiary coastal sedimentary basin covered by the Plio-Pleistocene age formations (series of circuses), formed of highly permeable sands comprising multiple resistant horizons that store large bodies of water whose reserves are considered very important. Hydrographic network is composed of four main basins with a mediocre size. The quality of this groundwater is considered to be satisfactory for household consumption, but the sustainable management of these reserves requires constant checks on their quality as well as on the level of the reserves. All these resources put the agglomeration of Pointe-Noire close to large exploitable water reserves that meet the need for drinking water, even if, on the whole, the agglomeration is still experiencing many difficulties in terms of its drinking water supply.

Urban Market-Gardening in Parakou (Republic of Benin): Spatial Dynamics, Food Security, Protection of the Environment and Creation of Employments

Nowadays, African cities are subjected to upsets which result from the extraordinary growth of urban populations. The growth of the population of cities has induced some changes in the structure of the activity of those cities. Agriculture which was formerly confined to the countryside henceforth develops in the urban area and occupies a preponderant place as a strategy of survival, of insertion and of food supplying of the city-dwellers. It has become an activity integrated to the urban tissue through systems of occupying and exploitation of land in the urban area. Population growth (4.81%) between 2002 and 2013 is a critical poverty rate (65%) of the population of Parakou city, entailing a misery perceptible in all its social and economic dimensions. The market-gardening activity has integrated itself to the urban tissue. The objective of this study is to understand how urban agriculture through market-gardening can be a solution for rural farmers who have moved to Parakou city. In this study, documentary research, interviews and field observation are used for data collection. The main results to be signaled among others are: evolution and status of the market-gardening areas in Parakou, the reduction of food insecurity with the permanent availability in quantity and in quality of market-gardening products accessible to the population: the protection of the environment through the drainage of the urban area and the preservation of the diversity of vegetables;the increase of the income of the households of the farmers and the creation of employments.

Quantitative Assessment of Vulnerability to Flood Hazards in Downstream Area of Mono Basin, South-Eastern Togo: Yoto District

The population located along Mono River in the Yoto district faces great challenges in terms of repeated flood disasters in recent years. This paper aims at assessing the conditions which influence flood damage in the study area by using indicators to compute a Flood Vulnerability Index (FVI). The study relies on Turner?et al.’s vulnerability framework and distinguishes three main components (exposure, susceptibility and resilience) that allow a more in-depth analysis and interpretation of local indicators. As a result flood disaster in the study area is not only due to the extreme variability in terms of flood magnitude and frequency in the Mono River, but also to the interaction between human and the environment. The lack of vegetation along the river bank, the closeness of households’ farmlands to the river body, the type of construction and the position of settlements, the household size, the low level education of household head, the lack of diversification of livelihood strategies, the lack of adequate flood warning system, the lack of willingness and ability to take responsive actions coupled with inadequate emergency services, are identified as main determinants increasing communities’ vulnerability to flood disaster. Furthermore, the computation of Flood Vulnerability Index (FVI) offers easy comparison of communities’ vulnerability to flood disaster and pinpoints the most vulnerable communities. At the end of the study, flood exposure, susceptibility, resilience and vulnerability maps were generated.

Stochastic Model for Multiple Classes and Subclasses Simple Documents Processing

The issue of document management has been raised for a long time, especially with the appearance of office automation in the 1980s, which led to dematerialization and Electronic Document Management (EDM). In the same period, workflow management has experienced significant development, but has become more focused on the industry. However, it seems to us that document workflows have not had the same interest for the scientific community. But nowadays, the emergence and supremacy of the Internet in electronic exchanges are leading to a massive dematerialization of documents;which requires a conceptual reconsideration of the organizational framework for the processing of said documents in both public and private administrations. This problem seems open to us and deserves the interest of the scientific community. Indeed, EDM has mainly focused on the storage (referencing) and circulation of documents (traceability). It paid little attention to the overall behavior of the system in processing documents. The purpose of our researches is to model document processing systems. In the previous works, we proposed a general model and its specialization in the case of small documents (any document processed by a single person at a time during its processing life cycle), which represent 70% of documents processed by administrations, according to our study. In this contribution, we extend the model for processing small documents to the case where they are managed in a system comprising document classes organized in subclasses;which is the case for most administrations. We have thus observed that this model is a Markovian ML×K/ML×K/1 queues network. We have analyzed the constraints of this model and deduced certain characteristics and metrics. In fine, the ultimate objective of our work is to design a document workflow management system, integrating a component of global behavior prediction.

Social Vulnerability Assessment to Flood in Medina Gounass Dakar

This paper is about the assessment of social vulnerability (SV) as a critical component of comprehensive disaster risk assessment. This study was conducted in Medina Gounass Dakar, Senegal, to bring out evidence that flooding was a threat to human security. The aim of this present study is to assess the social vulnerability to flood in Medina Gounass. Survey was carried out using structured questionnaires drawn on one hundred randomly selected households. For vulnerability assessment, the Methods for the Improvement of Vulnerability Assessment in Europe (MOVE) framework and Arc GIS are used to characterize vulnerability through three key factors, namely, 1) exposure, 2) susceptibility, and 3) lack of resilience. As a result, Medina Gounass inhabitants have a particular relationship with the place they have been living for decades. Although facing diseases and many challenges in their everyday life, people actually resist the government’s relocation projects because of their symbolic relationship with the area.

Contribution of Sentinel-2/Landsat-8 OLI Images to Extracting Vegetation Cover and Wetlands Area in Urban Zones: Case of the Dakar Region (Senegal)

Urban areas house vegetation cover in several forms, fulfilling several ecological functions like thermal regulator, biodiversity, air quality, etc. However, their extent is often not very well known, especially in African cities, making it sometimes difficult to assess their real impact on the urban ecosystem functioning. This work aims to analyse the capacity of satellite sensors for mapping vegetation and wetlands in urban areas. The data produced by the MSI sensors of Sentinel 2 and OLI of Landsat-8 are used to identify and map the vegetation cover in the Dakar region through a supervised classification with the Support Vector Machine (SVM) algorithm. The results show that it is sometimes not very easy to analyse urban vegetation with high spatial resolution images (HRS) resulting from the configuration of the vegetation in an urban environment, sometimes characterized by isolated trees or small green spaces. This explains why Sentinel-2 data which spatial resolution of 10 meters gives a better result compared to Landsat-8 data which is 30 meters. However, a good rendering is noted for the vegetation around the wetlands area for the two sensors resulting from the high density and the size of the vegetated perimeters in this part of the capital. Overall, there is an underestimation of urban vegetation cover, particularly for Landsat-8. The use of very high spatial resolution images could be necessary to better assess the potential of satellite data for monitoring urban vegetation in Sahelian context.

Critical Factors of Vulnerability That Enable Medina Gounass (Dakar/Senegal) to Adapt against Seasonal Flood Events

This paper focuses on people living in Medina Gounass where has been experiencing annually flood events during the rainy season. Besides the climatic conditions, the lack of formal amenity plan has led to the emergence of highly vulnerable urban communities, particularly through informal settlements and inadequate land management. Flood has disrupted their livelihood and caused huge loss of properties. Thus, inhabitants have a long experience of flood events. The study was carried out to assess critical aspects that led Medina Gounass inhabitants vulnerable to flood. Consequently, people in the study area have been practicing various methods at household to mitigate the probable losses. The study found that flood adaptation measures can be made more effective through community initiatives and their participation than at household level which sometimes causes harm in the neighborhood. Structural and non-structural flood management approach seems to be more efficient to alleviate Medina Gounass inhabitants from the flood problems.

Evaluation of the Physico-Chemical Quality and Potability of Groundwater Consumption in Department of Collines at Benin

The purpose of this study is to assess the physical and chemical quality of borehole water intended for consumption in the collines department in Benin. At the end of a sampling campaign, twenty-one (21) drinking water points were sampled. Different physico-chemical parameters were measured using standard analysis methods. The results of the analysis of the samples, showed that the groundwater of the department of the hills is characterized by a neutral pH and an average electrical conductivity in accordance with the WHO and Benin standard relating to the potability of groundwater. With this pH neutrality which would be linked to the nature of geological formations made up of crystalline rocks, the water in the hills is moderately hard with hardness values of 208 mg/L on average for magnesium ions of 22.54 mg/L on average and calcium ions of the order of 46.03 mg/L on average at the scale of the various localities and an alkalinity is of 43.81 mg/L on average. The values between 0 and 163.91 mg/L are low in the South-East and very high, even exceeding the standard accepted by WHO in the West and North-East of the study area. This nitrate pollution and the fairly high levels of organic matter in total nitrogen observed in the groundwater of the hills could also have an impact on the vulnerability of the water table. And this pollution with nitrates associated with electrical conductivity and chloride levels modifies and degrades from one drinking water point to another the potability of underground water in the hills.

人类活动与生态水文因素对塞内加尔北部费罗临时池塘周边的草本植物区系物种多样性的影响

在萨赫勒,临时池塘在保护物种多样性方面起着重要作用。本研究考察了塞内加尔北部费罗地区的两个放牧池塘以及一个未放牧池塘,探讨了人类活动与生态水文因素对池塘周边植物多样性的影响。每个池塘建立两条植物生态样带,确定并记录每条样带上平均植被单元情况(包括植被覆盖度、土壤暴露度、土壤质地、土壤湿度和酸碱度、平均高度以及坡度等)。研究结果表明,3个池塘周边共有草本植物22科41属55种。放牧池塘周边多为禾本科植物,尤其是画眉草属(Eragrostis tremula)与肠须草属(Enteropogon prieurii)植物,未放牧池塘周边则主要为其他科类植物,如牛膝属(Achyranthes sp.)、鸭跖草属(Commelina forsskaolii)、黄麻属(Corchorus sp.)植物等。Wendu Marodi池塘(未放牧池塘)的香农物种多样性指数(H′)为4.9,略高于Belel Lougal池塘和Belel Sow池塘(放牧池塘),这两个池塘的香农物种多样性指数分别为4.8和4.5。3个池塘的种类平均性指数相对都较高,分别为0.85、0.83和0.78。根据生态因子可分出4个物种群:蒺藜(Tribulus terrestris)种群,集中在限牧区与过度放牧区;平枝马唐(Digitaria horizontalis)种群与孟仁草(Chloris barbata)种群,见于过度带;以及土牛膝(Achyranthes aspera)种群,生长在人类活动较少且草本植物丰富的湿地。本研究强调了维持未放牧池塘或半保护池塘与放牧池塘景观镶嵌结构的重要性,以保护塞内加尔中心与萨赫勒地区草本植物的多样性。