Assessment of Environmental Geochemistry of Lead-Zinc Mining at Ishiagu Area, Lower Benue Trough, Southeastern Nigeria

Abstract

Mining activities have long been recognized as a major source of environmental contamination associated with heavy metals and metalloids. This study evaluated the relationship between the occurrence and mining of lead-zinc sulphide ores at Ishiagu, Nigeria, and heavy metal and metalloid contamination. A comparative study of two zones in the area, with and without mining activities was also made Water, soil, stream sediment and ore samples were analyzed, after acid digestion, using atomic absorption spectrophotometer (AAS).  The concentration levels of seven heavy metals and a metalloid namely Pb, Cu, Ni, Zn, Mn, Co, Cd and as were evaluated. While the highest concentration levels of As, Co and Pb (5.20 mg/l, 0.54 mg/l and 3.40 mg/l respectively) were found in water, those of Ni and Mn (2.26 mg/l and 5.48 mg/l respectively) occurred in soil.  For Cu and Zn, highest levels of concentration (2.80 mg/l and 0.41 mg/l respectively) occurred in stream sediments. The variations in the concentration levels of these elements in varying geologic media (soil, water and sediment) indicate influence of rock types, human activities and media physiochemical characteristics. Geostatistical analyses using QQPlot, semivariogram and kriging showed normal distribution of these elements. Distribution and dispersion patterns of the heavy metals indicated increase in concentration levels in the local stream flow direction. Pb, Cu, As, Cd, Mn, and Ni concentrations had reached pollutant levels in water based on WHO standards, while Zn level is below. Since the local people use untreated surface water and groundwater for drinking and other domestic purposes, soil for farming and lead for cosmetics, long term exposure poses significant health risk for humans, animals and plants.

Enrichment of Cd, Cr, Pb and Biological Detoxification Strategies in Sewage Irrigated Soils

“…Parent rocks and metallic minerals are examples of natural sources" [3]. According to [4,5,6] "anthropogenic causes include energy production (power plants, leaded petrol, etc. ), metallurgy (mine, smelting), agriculture (fertilisers, pesticides, etc.…”

Effect of the Substrate and Inoculation of Phosphate-Dissolving Bacterial and Fungal with Humic Acids in the Activity of the Alkaline Phosphatase Enzyme in Cadmium-Contaminated Soil

“…The main natural sources are volcanic eruptions, weathering of rocks containing these metals, and sea spray (Li et al, 2019; Khan et al, 2021). As for human sources of these metals, It occurs through various human activities such as mining, smelting, electroplating, coal combustion, vehicle exhaust, factories, chemical compounds, electric power, electronic devices, batteries, medical waste, and oil derivatives, which increases the occurrence of disturbance in the biological environment with the accumulation of large quantities of heavy metals in the environment, especially in the soil (Wang et al, 2019;Odika et al, 2020;Rajendran et al, 2022a).…”

Sequential Extraction and Mobility Factor of Metals in the Urban Soil of Warri-Nigeria (A Case Study of the Environment of Esisi Open Dump)

“…Heavy metals are metals that have atomic number greater than 20 and density greater than 5 g/cm 3 [1]. Basically, heavy metals are unarguably the transition and post transition metals, and the examples which are common in various literatures are lead (Pb), cadmium (Cd), vanadium (v) cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), arsenic (As), nickel (Ni), manganese (Mn), tin (Sn) zinc (Zn), and mercury (Hg).…”