Heavy metal contamination in tailings and rocksamples from an abandoned goldminein Southwestern Nigeria

Pollution and Ecological Risk Evaluation of Heavy Metals in the Soil and Sediment around the HTM Tailings Pond, Northeastern China

Tailings ponds are a main heavy metal pollution source in mining areas. In this study, the geo-accumulation index (Igeo) and the potential ecological risk index (RI) are used to evaluate the environmental impact of Hongtou Mountain (HTM) tailings pond on the surrounding area. Farmland soil, surface water, and sediment samples in the Hun River around the HTM tailings pond were collected. Heavy metal contents in the samples were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results show that Cu, Zn, and Cd content in the farmland soil and sediment around the lower reaches of the Hun River (HTM tailings pond section) are obviously higher than the upper reaches. The Igeo values show that the farmland soil near the outlet of the tailings pond is the most polluted area. Cu was classified as moderate-strongly pollution, Zn was moderately pollution, and Cd was strongly pollution. Cd is the major pollutant in farmland soil, the monomial ecological risk (Eri) for Cd is a very high potential ecological risk. The potential ecological risk of sediment in the dry season is more serious than in the raining season. In the dry season, the Igeo index shows strong pollution for Cu and Cd at the confluence of the Hun River and the tributary from the HTM tailings pond, and a moderate-strongly pollution for Zn. Whereas, the Eri index shows that the monomial ecological risk for Zn at H3 is low, and Cu is moderate. The potential ecological risk at H3 is high, and Cd is the main source of the ecological risk around the HTM tailings pond.

Potentially toxic elements in urban topsoils and health risk assessment for the mining W-Mo center in the Baikal region

The main threats to health are associated with the entry of potentially toxic elements (PTEs) into human bodies. The aim of this study is to assess the impact of the Zakamensk W-Mo deposit development on soil surface horizons and the health of the local population. The results of the geochemical survey of 2012 revealed the spatial distribution patterns and abundances of 15 PTEs. The elements bulk contents were determined by ICP-MS and ICP-AES. The impact of geochemical situation on the health of the population of Zakamensk was also assessed using the mortality rates from diseases of the digestive and respiratory organs, neoplasms, including malignant tumors of the digestive and respiratory organs in 2008-2012. The tailing dumps have increased concentrations of W, Cd, Pb, Sb, Mo, Cu, Zn, Sn, As, and Co due to petrochemical characteristics of the ore. The soils of the industrial zone accumulate W, Cd, Mo, Pb, Sb, Zn, Cu, and Sn due to the waste storage sites deterioration and the thermal power plant and the foundry emissions. The multi-story residential zone soils accumulate W, Cd, Pb, Zn, and Mo. Tungsten, Pb, Sb, Co, V, and Cr cause the greatest harm to adults and children and together account for 92-96% of the hazard index. Cadmium and Cr are the most dangerous carcinogenic elements in Zakamensk. Despite the closure of DTMP more than 15 years ago, the level of the total risk of developing malignant diseases indicates a catastrophic environmental situation.

Contamination of soils by potentially toxic elements in the impact zone of tungsten‑molybdenum ore mine in the Baikal region: A survey and risk assessment

Mining of mineral resources exerts strong impact on the environment and leads to irreversible changes in vegetation, soils, atmosphere, surface and ground waters. The aim of this study is to assess the modern geochemical state of soil cover in Zakamensk, a city located in Buryat Republic (Russia) and known as one of the biggest ore mining center in the former Soviet Union. The center was operating for 68 years and closed 17 years ago. Soil-geochemical survey was conducted in 2012 and included collection of 103 soil samples in Zakamensk and 27 samples in the background areas. The bulk contents of 16 potentially toxic elements (PTEs) in the soil samples were determined by mass spectrometry and by atomic emission spectrometry with inductively coupled plasma. Background sites are characterized by increased concentrations of ore elements W and Mo. The mineral deposit development and physical and chemical weathering of tailings' material have led to a sharp increase in Bi, Cd, Cu, Mo, Pb, Sb, W and Zn levels in the soils of different land-use areas. Near the tailings, the concentration of Sb in soils was 356 times higher than in the background area; Cd - 70 times; Mo, Bi, Cu, and W - 42-55 times; Pb and As - 34-37 times; and Zn and Sn - 6-12 higher. In the north of the city a prominent anomaly of PTEs occurs in sandy sediments of the Modonkul floodplain. It was formed due to the washout and subsequent sedimentation of suspended matter carried by the Modonkul River from the Barun-Naryn, the Dzhida, and emergency tailings. So, the anthropogenic activities are the most important source of ore and accompanying elements in the urban soils. High levels of accessory elements also depends on natural factors such as physicochemical properties of soils, position in the landscape, and genesis of parent materials. The environmental assessment of topsoils in Zakamensk showed that Pb, Sb, Cd, and As concentrations exceeds the Russian MPCs by 1.7-7.8 times, which creates a significant hazard for the environment and adversely affects human health.

Preliminary data on arsenic and trace metals concentrations in wetlands around artisanal and industrial mining areas (Cote d'Ivoire, West Africa)

This data article is issued from the research article ‘’Distribution trends and ecological risks of arsenic and trace metals in wetland sediments around gold mining activities in central-southern and southeastern Côte d’Ivoire’’ [1]. It presents arsenic and trace metal Cd, Pb, Cu, Zn, Cr, Co, Fe, Al, Mn, and Ni loadings in surface sediments collected from industrial mining, artisanal and small scale mining, and non-mining areas (West Africa). Are also provided, hierarchical dendrograms and factor loadings derived from the Hierarchical Clustering Analysis (HCA) and the principal component analysis (PCA), respectively. Data ranged from <LD-561 µg/g for As, 0.10–2.70 µg/g for Cd, 1.10–16.9 µg/g for Pb, 2.00–71.8 µg/g for Cu, 5.60–116 µg/g for Zn, 16.3–439 µg/g for Cr, 0.70–46.4 µg/g for Co, 11.9–175 mg/g for Fe, 7.49–93.3 mg/g for Al, 4.30–6442 µg/g for Mn, and 3.10–68.6 µg/g for Ni. These data are relevant for future research and sediment quality policy making at a regional level.

Speciation, Fate and Transport, and Ecological Risks of Cu, Pb, and Zn in Tailings from Huogeqi Copper Mine, Inner Mongolia, China

Tailings collected from the tailing reservoir at Huogeqi Copper Mine, located in Inner Mongolia, China, were used in a leachate study to evaluate the acid potential, neutralization potential, and possibility for producing acid mine drainage (AMD) from the site. The speciation of Cu, Pb, and Zn contained in the tailings was also determined during the leachate study to further access the potential migration abilities of these metals. The results showed that the tailings did not produce significant AMD as the pH of the leachate ranged from 7 to 9 and decreased with time. The Cu, Pb, and Zn concentrations were high, ranging from 439.1 to 4527 mg/kg in the tailings and from 0.162 to 7.964 mg/L in the leachate, respectively. Concentrations of metals in the leachate and tailings were positively correlated. Over 60% of the Cu in the tailing samples existed in an oxidizable form. Most of the Pb also existed in its oxidized form, as did the silicate and Zn. Metals usually have higher mobility in their exchangeable and oxidizable forms and as such represent a higher potential risk to the environment. Results of risk assessment code also revealed that metals in tailings exerted medium to high risks to the environment.

Biotechnology of siderophores in high-impact scientific fields

Different aspects of bacterial and fungal siderophore biotechnological applications will be discussed. Areas of application presented include, but are not limited to agriculture, medicine, pharmacology, bioremediation, biodegradation and food industry. In agriculture-related applications, siderophores could be employed to enhance plant growth due to their uptake by rhizobia. Siderophores hindered the presence of plant pathogens in biocontrol strategies. Bioremediation studies on siderophores discuss mostly the mobilization of heavy metals and radionuclides; the emulsifying effects of siderophore-producing microorganisms in oil-contaminated environments are also presented. The different applications found in literature based in medicine and pharmacological approaches range from iron overload to drug delivery systems and, more recently, vaccines. Additional research should be done in siderophore production and their metabolic relevance to have a deeper understanding for future biotechnological advances.

Urinary Metal Levels in a Chilean Community 31 Years After the Dumping of Mine Tailings

BACKGROUND

Between 1938 and 1975, the city of Chañaral, located in the north of Chile, received 200 megatons of unregulated mining waste, which created an artificial beach 10 kilometers long and covering an area larger than 4 km2. In 1983, this deposit was classified as a serious case of marine pollution in the Pacific Ocean, according to the Organization for Economic Cooperation and Development. In 1989, dumping ceased due to a judicial order. Until now, the effects of this pollution on the population living around these mine tailings has been unknown.

OBJECTIVE

To determine the prevalence of exposure to metals by dust from mine tailings in Chañaral, a city located in the northern mining area of Chile.

METHODS

The level of urinary metals in a representative sample of adults from Chanaral was determined.

RESULTS

Urinary levels of total arsenic (44.6 μg/L), inorganic arsenic (17.0 μg/L) and nickel (2.8 μg/L) were higher than in other areas of Chile. Levels of copper (17.9 μg/L), mercury (1.6 μg/L) and lead (0.9 μg/L) exceeded international values. Of the total subjects, 67.5%, 30.4%, 29.4%, 16.9%, 13.2 and 9.3% presented with high levels of copper, nickel, total arsenic, inorganic arsenic, mercury and lead, respectively.

CONCLUSION

Thirty-one years after suspension of the discharge of mining waste, the local population in this area remains exposed to metals from the mine tailings. Surveillance and remedial actions addressing the Chañaral mine tailings are needed.