Spatial distribution and potential ecological and health risks associated with heavy metals in the Ijero-Ekiti mining site,Nigeria

Artisanal gold mining,a labor-intensive and antiquated technique,is a growing industry and the source of income for rural communities all over the world.However,artisanal gold mining has potential negative and long-term effects on economy,environment,and society.This study collected soil samples from 16 sample points including a control point to examine the pollution degrees and spatial distribution of heavy metals,as well as ecological and health risks associated with heavy metal pollution in the Ijero-Ekiti mining site,Nigeria.Geographical Information System(GIS)and remote sensing technologies were used to identify regions with high concentrations of heavy metals and assess the environmental impact of gold mining activities.The results show that the mean heavy metal concentrations of 16 soil pointa are 8.94(±5.97)mg/kg for As,0.18(±0.54)mg/kg for Cd,0.11(±1.06)mg/kg for Co,14.32(±3.43)mg/kg for Cr,6.89(±0.64)mg/kg for Cu,48.92(±11.77)mg/kg for Fe,135.81(±30.75)mg/kg for Mn,5.92(±0.96)mg/kg for Ni,5.72(±1.66)mg/kg for Pb,and 13.94(±1.38)mg/kg for Zn.The study reveals that heavy metal concentration in soils follows the order of Mn>Fe>Cr>Zn>As>Cu>Ni>Pb>Co>Cd.An analysis of soil samples indicates that 3 principal components(PCs)account for 70.008%of the total variance and there are strong positive correlations between various pairs of heavy metals.The total potential ecological risk index(309.599)in the study area is high.Non-carcinogenic risk suggests that there may be long-term health impacts on people who work in the mining areas due to chronic exposure to the environment.Based on the study,the hazard index of carcinogenic health risks associated with heavy metals through ingestion is 520.00×10^(–4).Dermal contact from As and Cr also increases the risk of cancer,with the highest hazard index value of 18.40×10^(–4).The lowest exposure pathway,with the hazard index value of 0.68×10^(–4),indicates that the inhalation of heavy metals has a comparatively low risk of cancer.This study recommends the formulation of policies to monitor the Ijero-Ekiti mining site and other regions in Nigeria where indiscriminate artisanal gold mining activities exist.

Distribution characteristics and environmental risk assessment following metal(loid)s pollution incidents at Southwest China mining site

Limited information is available on long-term effects of metal(loid)s pollution incidents. Here, we analyze the distribution characteristics and quantification of elements in the Southwest China Keda mining site, which is one of the most populated sites and enables human health and ecological risk assessments of elemental pollution. The results on modified degree of contamination indicated that the soil and sediment were highly contaminated near Dahu Lake.The health risk of children was almost 2.5 times that of adults in surface water, and 7.1 times in soil, respectively.Moreover, Tl and As were the main health risk contributors in surface water and soil, respectively, and As posed the highest ecological risk both in soil and sediment. These results indicated the potential impact of toxic metal(loid)s on the health of residents and environment. Hence, more scientific attention and proper management need to be paid to this environmental challenge in the future.

Microinvasive analysis of textile relics from an ancient Silk Road turquoise mining site

The Xinjiang region,with its unique location and climate,exhibits well-preserved relics of great academic interest.This paper focuses on the microinvasive analysis of textile samples obtained from an ancient turquoise mining site in the Heishanling region of Xinjiang,active between 820 and 400 BC.Various analytical techniques,including optical microscopy,scanning electron microscopy,Fourier-transform infrared spectroscopy with attenuated total reflection,and liquid chromatography-mass spectrometry,were employed to investigate these textiles.The results revealed that the textiles were composed of wool and dyed using indigo and purpurin.The bluegrass and madder-derived dyes were likely sourced locally or imported from wetter regions such as the Chinese Central Plains.The infrared deconvolution spectra and the results demonstrated that red and blue dyes considerably influenced the movement of wool fiber chains,leading to a more rapid decay of dyed fibers compared to those that were undyed.In addition,the medium dyeing process and Ke techniques were employed to create unique color shades and special patterns.This scientific and technological analysis of the textiles provides essential data for elucidating the materials available to ancient laborers.Furthermore,it offers scientific evidence supporting the cultural exchange between the western regions and the Central Plains and integration along the Silk Road.

Development of plant communities after restoration of the Antaibao mining site, China

To investigate the dynamic changes in the artificial vegetation in an abandoned mining site,we analyzed the re lationships among community types,environmental variables and community structure in the process of vegetation restoration in the Antaibao mining site,China by survey of the communities and use of biological dating methods.By means of the quantitative classification method(two-way indicator-species analysis,TWINSPAN)and the ordination technique(de-trended correspondence analysis,DCA;and de-trended canonical correspondence analysis,DCCA),the plant communities were classified into seven groups:community I,Robinia pseudoacacia+Pimus tabulaeformis-Caragana kor-shinskii-Agropyron cristatum;community II,Robinia pseudoacacia-Hippophae rhamnoides-Artemisia capil-laries;community II,Ulmus pumila-Elaeagmus angu-stifolia-Artemisia capillaries;community IV,Caragana korshinskii-Agropyron cristatum+Artemisia capillaries;community V,Hippophae rhamnoides-Elymus dahur-icus;community VI,Elaeagnus angustifolia+Hippophae rhamnoides-Brassica jucea;community VII,Hippophae rhammoides+Elaeagnus angustifolia-Salsola collina.We conclude that the community types and diversity are mainly influenced by the succession time and the soil organic matter content.The forest community is more adaptable to the special inhabitation than the shrub community.

Aspects of surface and environment protection in German mining areas

Hard coal mining in the German Ruhr district has a tradition of more than 200 years. Starting in the south near the river Ruhr with mining of seams near to the surface, mining wandered to the north with coal seams deeper and deeper. In the same way all environmental effects of mining wandered from south to north, as there are abandoned mining sites, contaminated areas, burning mining dumps, subsided areas and gas accesses at day ground. This all happened in a very high populated area with more than four million inhabitants. Therefore Germany has a long tradition in solving environmental problems of mining activities. The very good interaction of mine authority, mining companies and the mine workers’ union is the main reason why the problems of decreasing mining activities in Germany were solved without economic, environmental or social hazards.

Deformation features and failure mechanism of steep rock slope under the mining activities and rainfall

Underground mining activities and rainfall have potential important influence on the initiation and reactivation of the slope deformations,especially on the steep rock slope. In this paper,using the discrete element method(UDEC),numerical simulation was carried out to investigate deformation features and the failure mechanism of the steep rock slope under mining activities and rainfall. A steep rock slope numerical model was created based on a case study at the Wulong area in Chongqing city,China. Mechanical parameters of the rock mass have been determined by situ measurements and laboratory measurements. A preliminary site monitoring system has been realized,aiming at getting structure movements and stresses of unstablerock masses at the most significant discontinuities. According to the numerical model calibrated based on the monitoring data,four types of operation conditions are designed to reveal the effect of mining excavation and extreme rainfall on the deformation of the steep rock slope.

Visceral Leishmaniasis at the National Reference University Hospital Center of N’Djamena (Chad): Epidemiological, Clinical, Diagnostic, Therapeutic and Prognostic Aspects

Introduction: leishmaniasis is a group of parasitic diseases caused by a parasite of the genus Leishmania transmitted by the bite of an infected vector called a sandfly. There are four forms. Visceral leishmaniasis is the most severe form. The aim of our work is to study the epidemiological, clinical, diagnostic, therapeutic and prognostic aspects of the disease in the Infectious Diseases Department of the Centre Hospitalier Universitaire de Référence Nationale in N'Djaména. Methodology: Patients were recruited on the basis of clinical signs suggestive of visceral leishmaniasis, i.e. prolonged fever, splenomegaly and altered general condition. Biological confirmation was performed with a rapid diagnostic test using recombinant K39 parasite antigen, which is known to have good specificity and sensitivity. Epidata version 3.1 software was used to process patient data. Results: From 05/04/21 to 15/12/23, 153 positive cases were managed. The mean age of patients was 18 years, with a sex ratio of 9.2. Of these patients, 103 (67.3%) had recently stayed at gold mining sites. Patients testing positive were treated with sodium stibogluconate combined with paromomycin for 17 days. The mortality rate was 13.2%. Conclusion: Leishmaniasis is a serious and little-known disease in Chad. In order to respond to the disease, it is necessary to reinforce the capacities of health structures and to carry out appropriate actions in the outbreaks.

Soil quality index as a tool for Scots pine(Pinus sylvestris) monoculture conversion planning on afforested,reclaimed mine land

In Central Europe, a large portion of post-mining sites were afforested with Scots pine, which is characterized by good adaptability and a tolerance for poor habitat at the beginning of forest ecosystem development. Conversion of monoculture on mine sites into more biodi- verse mixed hardwood forests, especially on more fertile deposits, can be an emerging need in this part of Europe in next decades. The ability to classify the forests at these post-mining sites will facilitate proper species selection as well as the management and formation of the developed ecosystem＇s stability. This work describes the guidelines that can be followed to assess reclaimed mine soil （RMS） quality, using the mine soil quality index （MSQI） and a classification of developed forest sites as a basis of tree-stand species selection and conversion of pine monocul- tures. The research was conducted on four post-mining facilities （lignite, hard coal, sulphur, and sand pit mining areas） on different RMS sub- strates dominant in Central Europe. Soil quality assessment takes into account the following features of the soil： texture soil nutrients （Ca, Mg, K, Na, P）; acidity （pH KC1）; and Corg-to-Nt ratio in the initial organic horizon. An analysis was conducted of classification systems using the MSQI validation correlation （at p =0.05） with vegetation features af- fected by succession： aboveground biomass of forest floor and ecological indicators of vascular plants （calculated on the basis of EUenberg＇s （2009） system）. Eventually, in the analysed data set, the MSQI ranged from 0.270 for soils on quaternary sands to 0.720 for a mix of quaternary loamy sands with neogene clays. Potential forest habitat types and the role of the pine in the next generation of tree stands on different RMS parent rock substrate were proposed.

Enduring legacy of coal mining on the fungal community in a High Arctic soil after five decades

Mineral extraction is known to affect soil fungi in polar environments,but it is unknown how long these effects persist.Here,by amplifying the internal transcribed spacer regions of rRNA genes in soil fungi,we compared soil fungal community in intact natural tundra with that in a nearby former coal mining area,abandoned 52 years previously,on Svalbard in the High Arctic.Compared with those in intact tundra,soils in the former mining area were more acidic and had lower plant coverage.Despite of similar diversity in the two areas,the fungal community was dominated by Basidiomycota in the intact tundra,but by Ascomycota in the former mining area.Ectomycorrhizal genera formed a major part of the tundra community,but were notably less abundant in the mining area.The principal variation among samples was soil pH.Surprisingly,network connectivity analysis indicated that the fungal community in the former mining area had greater network connectivity than that in the tundra area.Overall,the ecosystem in the former mining area has made only limited recovery towards the natural tundra state even after more than five decades.It is unclear whether the recovery of the fungal community is limited more by the low primary productivity,slow migration of fungi and plants,or slow changes in soil parameters.Our findings emphasize the susceptibility of polar ecosystems to disturbance,given their particularly slow recovery back towards the natural state.