Artisanal gold‐mining in a rural environment: Land degradation in Kenya

Abstract

Artisanal gold‐mining (AGM) is one of the most important activities in the districts of Migori and Transmara (Kenya). Gold‐mining, however, is known to release vast quantities of arsenic and metals (some of which are very toxic like As, Hg, Cd, or Pb), which poses a serious threat to not only miners but also to the ecosystem and local populations. We, herein, determine the concentrations of arsenic and some heavy metals in several sample types (i.e., ore, soil, river sediment, and mine tailing) collected from the districts of Migori and Transmara. We also employ lichens and mosses as pollution bioindicators. Geostatistical tools and canonical correlation analysis were used to identify the relevant factors that affected arsenic and metal concentrations in the analysed samples. The following concentration ranges were reported in topsoil: As (1–17,250 mg kg−1), Cd (0.01–15.10 mg kg−1), Cu (7–9,238 mg kg−1), Cr (1–214 mg kg−1), Ni (5–766 mg kg−1), Pb (3–1,149 mg kg−1), and Zn (22–1,271 mg kg−1). It was concluded that the ecosystem in both districts was highly polluted by heavy metals whereas the arsenic concentrations in topsoil were among the highest reported worldwide. The results of this study provide new evidence on the impact of AGM on the environment and may further contribute to the design of policy measures with the aim of reducing environmental and human health risks associated to AGM activities.

Soil organic carbon stock on the Majorca Island: Temporal change in agricultural soil over the last 10 years

“…The general linear model included two-way and interactions between main effects. A simple geostatistical analysis was used to generate kriging maps of the percentages of SOC, BD and coarse fragments fraction (Goovaerts, 1997;Lv et al, 2015;Odumo et al, 2018;Rodriguez Martin et al, 2014). Spherical models were used to fit the experimental semivariograms and ordinary kriging (OK) was utilised to estimate SOC (%), BD (g cm -3 ) and Stoniness (%) as a map grid of 100 x 100 m (1 ha).…”

Kenya’s Mineral Landscape: A Review of the Mining Status and Potential Recovery of Strategic and Critical Metals through Hydrometallurgical and Flotation Techniques

“…Lamu County is rich in Ti, gas, and oil, whereas Migori County has commercially exploitable deposits of Zn, diamond, Au, Al, Fe, and Cu. Au generation in Migori and other regions is a significant driver of the nation's economic development and growth, contributing approximately USD 10.3 million/year to the country's economy [24]. Transmara and Migori districts began to mine Au in the year 1930.…”

“…This is mainly predominant when sulphide minerals are involved while extracting Au. Other metals released during artisanal Au mining in regions like Migori and related industries include Cu, Cd, Ni, Zn, Pb, and As, all discharged into soil and water bodies [24].…”

Assessing Social and Environmental Impacts of Artisanal and Small-Scale Gold Mining Practices in Lolgorian, Kenya

“…According to Odumo et al (2018), the Transmara-Migori mining environment is heavily contaminated by heavy metals. Mining trends and practices have an impact on the level of environmental degradation in Lolgorian, with 60.4% agreeing that present mining activities have increased deforestation and environmental degradation.…”