Heavy metals in soils along unpaved roads in south west Cameroon: Contamination levels and health risks

Ngole‐Jeme, Veronica M.

doi:10.1007/s13280-015-0726-9

Cited by 29 publications

(15 citation statements)

References 34 publications

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“…Significant differences were therefore reported at a probability (p) value of 0.05. To determine the extent of heavy metal contamination in soils at the landfill, heavy metal contamination factor (CF) for each of the heavy metals analyzed was calculated according to equation (1) as recommended by Hakanson [41] and Ngole-Jeme [42]:…”

Section: Data Analysesmentioning

confidence: 99%

Soil Heavy Metal Distribution with Depth around a Closed Landfill and Their Uptake by Datura stramonium

Makuleke

Ngole‐Jeme

2020

Applied and Environmental Soil Science

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Landfills are major sources of environmental pollution. This study evaluated heavy metal concentrations in soils and plants around the closed Lumberstewart landfill in Bulawayo, Zimbabwe, to determine the pollution potential of a closed landfill and the risks they present to plants growing in this environment and surrounding communities. Soil samples were collected at depths of 0–30 cm, 30–60 cm, and 60–90 cm around the landfill and at a control site and characterized for various properties and concentrations of Cd, Cu, Cr, Fe, Ni, and Zn. Samples of Datura stramonium, collected from the same sites where soil samples were collected, were also analyzed for the same heavy metals. The soils were sandy, mostly acidic (5.01 < pH < 7.65) with low organic matter content (<2%) and cation exchange capacity (<15 meq/100 g). These properties varied with depth around the landfill. Heavy metals concentrations in the soils and Datura stramonium followed the order Fe > Zn > Cu > Cr > Ni > Cd with samples from around the landfill having higher concentrations than samples from the control site. Soil heavy metal enrichment was highest at a depth of 30–60 cm. Pollution load index (PLI) values indicated that all sites around the landfill were polluted (PLI > 1). Heavy metal transfer coefficient in Datura stramonium ranged between 0.0 and 209 with <60% of the variation observed in heavy metal transfer coefficient in Datura stramonium explained by the extent of heavy metal enrichment in the soils. More than 20 years after closure of the landfill, there are indications that leachate migration may still be going on around the landfill. Monitoring of environments around closed landfills needs to be ongoing to mitigate negative impacts on humans and the environment.

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Section: Data Analysesmentioning

confidence: 99%

Soil Heavy Metal Distribution with Depth around a Closed Landfill and Their Uptake by Datura stramonium

Makuleke

Ngole‐Jeme

2020

Applied and Environmental Soil Science

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“…Furthermore, owing to the fact that this change is quite recent, leaded fuel may still be a source of Pb enrichment since Pb from gasoline is normally found in aerosol particles for a long time after the introduction of unleaded fuel. Also, according to Ngole (2016), cultivation areas near highways are also exposed to atmospheric pollution in the form of metal containing aerosols.…”

Section: Heavy Metal Contamination In Cabbage and Carrotmentioning

confidence: 99%

An assessment of heavy metal exposure risk associated with consumption of cabbage and carrot grown in a tropical Savannah region

Fonge

Larissa

Egbe

et al. 2021

Sustainable Environment

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Indiscriminate use of fertilizers by vegetable growers and poor water quality of irrigational water characterize vegetable production in most parts of Cameroon. The concentrations of As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in the soil, cabbage and carrot cultivated in Santa, North West Region, Cameroon were assessed to determine potential ecological and human health risk associated with the consumption of these two vegetables. Heavy metal concentrations were determined using a ContrAA 300 Atomic Absorption Spectrophotometer after microwave digestion. The concentrations of As (0.51 mg/kg and 0.38 mg/kg), Co (1.41 mg/kg and 1.39 mg/kg) and Pb (1.36 mg/kg and 1.31 mg/ kg) in the cabbage and carrot, respectively, were above the WHO/FAO, permissible limits for human consumption. Health risk index values for Co in cabbage (2.31 mg/kg) and carrot (2.26 mg/kg) indicated significant risks from Co exposure. Geo-accumulation Index indicated that soils from most sites were contaminated. The populations consuming these vegetables are at risk of As, Co and Pb toxicity. Monitoring and sensitization of farmers on the effects of indiscriminate use of agrochemicals is very necessary to protect the health of consumers and preserve the soil quality.

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“…If some heavy metals with both carcinogenic and teratogenic enter the bloodstream, they can dissolve red blood cells, destroy normal cells 27 . For example, Zn generates gastrointestinal distress including nausea, vomiting, and abdominal pain as well as irritation of the respiratory system 28 . Besides, cholesterol balance and fertility may be affected by Zn with long-term high dose exposure 29 .…”

Section: Introductionmentioning

confidence: 99%

Retrieving zinc concentrations in topsoil with reflectance spectroscopy at Opencast Coal Mine sites

Guo

Zhang

et al. 2021

Sci Rep

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Heavy metals contaminations in mining areas aroused wide concerns globally. Efficient evaluation of its pollution status is a basis for further soil reclamation. Visible and near–infrared reflectance (Vis–NIR) spectroscopy has been diffusely used for retrieving heavy metals concentrations. However, the reliability and feasibility of calibrated models were still doubtful. The present study estimated zinc (Zn) concentrations via the random forest (RF) and partial least squares regression (PLSR) using ground in-situ Zn concentrations as well as soil spectral reflectance at an Opencast Coal Mine of Ordos, China in February 2020. The coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), and the ratio of performance to deviation (RPD) were selected to assess the robustness of the methods in estimating Zn contents. Moreover, the characteristic bands were chosen by Pearson correlation analysis and Boruta Algorithm. Finally, the comparison between RF and PLSR combined with eight spectral reflectance transformation methods was conducted for four concentration groups to determine the optimal model. The results indicated that: (1) Zn contents represented a skewed distribution (coefficient of variation (CV) = 33%); (2) the spectral reflectance tended to decrease with the increase of Zn contents during 580–1850 nm based on Savitzky–Golay smoothing (SG); (3) the continuous wavelet transform (CWT) demonstrated higher effectiveness than other spectral reflectance transformation methods in enhancing spectral responses, the R2 between Zn contents and the soil spectral reflectance achieved the highest (R2 = 0.71) by using CWT; (4) the RF combined with CWT exhibited the best performance than other methods in the current study (R2 = 0.97, RPD = 3.39, RMSE = 1.05 mg kg−1, MAE = 0.79 mg kg−1). The current study supplied a scientific scheme and theoretical support for predicting heavy metals concentrations via the Vis–NIR spectral method in possible contaminated areas such as coal mines and metallic mineral deposit areas.

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Heavy metals in soils along unpaved roads in south west Cameroon: Contamination levels and health risks

Cited by 29 publications

References 34 publications

Soil Heavy Metal Distribution with Depth around a Closed Landfill and Their Uptake by Datura stramonium

Soil Heavy Metal Distribution with Depth around a Closed Landfill and Their Uptake by Datura stramonium

An assessment of heavy metal exposure risk associated with consumption of cabbage and carrot grown in a tropical Savannah region

Retrieving zinc concentrations in topsoil with reflectance spectroscopy at Opencast Coal Mine sites

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