Utility of pollution indices in assessment of soil quality around Madaga gold mining site, Niger state, North-central Nigeria

Abstract

The quality of soil in the vicinity of Madaka mining sites were investigated in this study using Environmental Pollution Indices. Geological mapping of the study area indicated that the area was dominated by schist and granite. The static water level measurement revealed a westward groundwater flow direction which also coincides with the regional structural trend of the area. Laboratory analyses of soil and stream sediment were carried out in National Geosciences Research Laboratory Kaduna. The results of the soil analyses revealed high concentrations of mercury, cadmium, lead and arsenic. The results of the laboratory analysis were further elucidated using pollution indices such as geo-accumulation index, contamination factor, degree of contamination, elemental contamination index and metal pollution index. These environmental indices revealed that the soil is seriously polluted with mercury, cadmium and lead, moderately polluted with arsenic, lightly polluted with iron and copper and very lightly polluted with manganese, zinc, nickel and cobalt in the order of: Hg > Cd >Pb> As > Fe > Cu > Mn > Zn > Ni > Co. The mean concentrations of the first four metals (Hg, Cd, Pb and As) exceeds their average crustal abundance, which is an indication of possible pollution. The concentrations map of the analyzed heavy metals indicated a westward decrease in concentration away from the mine sites. This was in agreement with the flow direction and the possible reduction in pollution intensity away from the mine sites could be attributed to the natural attenuation mechanism of soil in the course of groundwater migration as well as hydrogeological attributes of the area. The study recommends that the miners be grouped into association and trained on modern mining techniques that are environmental friendly. The polluted soils in the area should be remediated and proper sensitization on the dangers associated with artisanal mining should be carried out in the area. Periodic monitoring of the soil quality in the area is advocated. Keywords

Electrochemical determination of the levels of lead and cadmium in soil samples from Niger and Ogun States, Nigeria: remediation potential with chitosan phosphate and implications for human health and disease

“…The highest levels of Pb and Cd in the study where 808.16 and 116.91 mg/kg respectively. A study on the environmental impact of artisanal gold mining in Luku, Minna, Niger State, Nigeria has also been reported [17] The results shown in the present study as well as those reported in the literature [16] show that the soil samples from Maigiro, Kawo in Rafi LGA are heavily contaminated by Pb and Cd. Contamination in Madaka was found to be lower.…”

“…In a study on the utility of pollution indices in the assessment of soil quality around Madaga gold mining site, Niger State, North-Central Nigeria, it was reported that the soil around the gold mining sites is seriously polluted by mercury, cadmium and lead, moderately polluted with arsenic, lightly polluted with iron and copper and very lightly polluted with manganese, zinc, nickel and cobalt in the order of Hg > Cd > Pb > As > Fe > Cu > Mn > Zn > Ni > Co [16]. The highest levels of Pb and Cd in the study where 808.16 and 116.91 mg/kg respectively.…”

“…Several workers have carried out studies on the levels of heavy metals in soil samples from different communities in Zamfara State [9][10][11][12][13][14][15] but few studies have been carried out on soil contamination in mining communities in Niger State [16][17][18]. These studies employed the use of atomic absorption spectrometry (AAS) which involve pretreatment procedures such as wet digestion, dry ashing and microwave oven dissolution or extraction.…”

“…Metal concentrations in soil samples from selected locations in Niger and Ogun States to the artisanal gold mining activities in these locations in Rafi LGA of Niger State, Nigeria. Galena (PbS) has been reported as the compound in the gold ore present in this community[16]. After excavation, the galena is discarded by the miners as gangue on the soil in the environment where it is subsequently leached into the subsurface.…”

Effect of heavy metals and physicochemical parameters on diversity of plants at a gold mine tailings dam in Ghana

“…Moreover, Kabas et al (2017) indicated that under acidic conditions bioavailability of metals increases therefore accentuating their effect in plants. Comparatively, the pH and nutrient levels in soil are lower than other abandoned mine sites in China, Portugal, Poland and Nigeria (Guo et al, 2019;Amadi et al, 2017;Kasowska et al, 2018;Pratas et al, 2005). The low nutrient level at study area is known to impair optimal growth and development of plants (Mensah, 2015).…”