Mining resources are offered by the natural milieu and liable to exploitation. Raw materials extracted are essential for jewellery and economy. But in most cases, the environmental impact assessment is disappointing. ...Mining resources are offered by the natural milieu and liable to exploitation. Raw materials extracted are essential for jewellery and economy. But in most cases, the environmental impact assessment is disappointing. In this study conducted at Betare Oya, mining residues are directly disposed in the immediate environment without passing through the tailing ponds for treatment, despite environmental laws and standards. Soluble components of matter are slowly dissolved, drained by meteoric water and flowed into tail bay vicinity. Soil and mining residues were sampled in Mari, Mbigala, Mboufa and Bedobo, respectively, four sub-watershed of Lom, the main river of the region. Concentration of nine MTE （metallic trace elements）： As, Cd, Cr, Cu, Co, Ni, Pb, Zn and Hg were determined by ICP-MS （inductively coupled plasma-mass spectrometry）. Highest concentrations of trace and toxic metals in soil and mining residues are： Cr （210 mg·kg-1） 〉 Zn （136 mg·kg-1） 〉 Ni （64 mg·kg-1） 〉 As （34 mg·kg-1） 〉 Cu （30 mg·kg-1） 〉 Pb （25 mg·kg-1） 〉 Co （17 mg·kg-1） 〉 Cd （0.5 mg·kg-1） 〉 Hg （0.1 mg·kg-l）, respectively. These results let assume that it is a risk of environmental pollution and poisoning relative to these elements around Betare Oya opencast mining area, with impact on human health.展开更多
In Cameroon, most farmers rely on their perceptions for fertility evaluation and choice of agricultural land units. However, because of environmental change, this knowledge is mostly disregarded. The use of farmers＇ ...In Cameroon, most farmers rely on their perceptions for fertility evaluation and choice of agricultural land units. However, because of environmental change, this knowledge is mostly disregarded. The use of farmers＇ knowledge is important for the identification of relevant information for the choice of agricultural land units. The objective of this study was to compare farmers＇ perceptions of soil fertility with a conventional scientific approach in two locations of the forest margin zone of Center Cameroon. Through interviews and soil analysis, this study spelled and weighed the relationships between farmers＇ perceptions and soil fertility status. One hundred and twenty households＇ heads were interviewed and 30 soil samples collected. Farmers＇ perceptions were used to assess the topsoil fertility status across the studied areas, while a conventional scientific approach was used to quantify soil fertility status by the means of a soil fertility index （SFI）. Results showed that farmers, for soil differentiation, used color, texture, depth, drainage and vegetation. Soil＇ names delivered key messages for their location. Although the low overall SFI approximated by the conventional approach, farmers＇ perceptions could differentiate fertility levels between soils. This knowledge is relevant for the design of technical innovations in perceived fertility niches.展开更多
The nexus between water, food and energy is one of the most fundamental relationships and challenges for society. Indeed, seepage of wastes stored into dumping sites of Edea township, favor their lixiviation. Soluble ...The nexus between water, food and energy is one of the most fundamental relationships and challenges for society. Indeed, seepage of wastes stored into dumping sites of Edea township, favor their lixiviation. Soluble components of matter are slowly dissolves, drained by meteoric water and flowed into tail bay vicinity. Knowledge of trace and toxic metal concentrations in the biotic matrices is important for assessing the effects of pollutants and the risk of exposure. In this study, A1, Mn, Cd, Cr, Cu, Pb and Zn were quantified respectively in 33 samples of soil and water, using ICP-MS （Inductively Coupled Plasma Mass Spectrometry）, Pb were found between 1.38-88.28 mg/L. Higher concentrations of Al were found in Alucam industrial wastes （315,502.33 mg/kg）, and in Hysacam domestic wastes （54,126.93 mg/kg）. Concentrations of Cd （1.955 mg/kg）, Pb （469.00 mg/kg） and Zn （853.00 rng/kg） are higher in domestic wastes. The ones of Mn （696.96 mg/kg） and Cu （1,320.10 mg/kg） are higher in industrial wastes. Higher concentrations of Pb and Cu let assume that it is a risk of poisoning relative to these elements around this area. These findings illustrate that lixiviation of dumping wastes has great influence on water and soils pollutions of the study ecosystem.展开更多
文摘Mining resources are offered by the natural milieu and liable to exploitation. Raw materials extracted are essential for jewellery and economy. But in most cases, the environmental impact assessment is disappointing. In this study conducted at Betare Oya, mining residues are directly disposed in the immediate environment without passing through the tailing ponds for treatment, despite environmental laws and standards. Soluble components of matter are slowly dissolved, drained by meteoric water and flowed into tail bay vicinity. Soil and mining residues were sampled in Mari, Mbigala, Mboufa and Bedobo, respectively, four sub-watershed of Lom, the main river of the region. Concentration of nine MTE （metallic trace elements）： As, Cd, Cr, Cu, Co, Ni, Pb, Zn and Hg were determined by ICP-MS （inductively coupled plasma-mass spectrometry）. Highest concentrations of trace and toxic metals in soil and mining residues are： Cr （210 mg·kg-1） 〉 Zn （136 mg·kg-1） 〉 Ni （64 mg·kg-1） 〉 As （34 mg·kg-1） 〉 Cu （30 mg·kg-1） 〉 Pb （25 mg·kg-1） 〉 Co （17 mg·kg-1） 〉 Cd （0.5 mg·kg-1） 〉 Hg （0.1 mg·kg-l）, respectively. These results let assume that it is a risk of environmental pollution and poisoning relative to these elements around Betare Oya opencast mining area, with impact on human health.
文摘In Cameroon, most farmers rely on their perceptions for fertility evaluation and choice of agricultural land units. However, because of environmental change, this knowledge is mostly disregarded. The use of farmers＇ knowledge is important for the identification of relevant information for the choice of agricultural land units. The objective of this study was to compare farmers＇ perceptions of soil fertility with a conventional scientific approach in two locations of the forest margin zone of Center Cameroon. Through interviews and soil analysis, this study spelled and weighed the relationships between farmers＇ perceptions and soil fertility status. One hundred and twenty households＇ heads were interviewed and 30 soil samples collected. Farmers＇ perceptions were used to assess the topsoil fertility status across the studied areas, while a conventional scientific approach was used to quantify soil fertility status by the means of a soil fertility index （SFI）. Results showed that farmers, for soil differentiation, used color, texture, depth, drainage and vegetation. Soil＇ names delivered key messages for their location. Although the low overall SFI approximated by the conventional approach, farmers＇ perceptions could differentiate fertility levels between soils. This knowledge is relevant for the design of technical innovations in perceived fertility niches.
文摘The nexus between water, food and energy is one of the most fundamental relationships and challenges for society. Indeed, seepage of wastes stored into dumping sites of Edea township, favor their lixiviation. Soluble components of matter are slowly dissolves, drained by meteoric water and flowed into tail bay vicinity. Knowledge of trace and toxic metal concentrations in the biotic matrices is important for assessing the effects of pollutants and the risk of exposure. In this study, A1, Mn, Cd, Cr, Cu, Pb and Zn were quantified respectively in 33 samples of soil and water, using ICP-MS （Inductively Coupled Plasma Mass Spectrometry）, Pb were found between 1.38-88.28 mg/L. Higher concentrations of Al were found in Alucam industrial wastes （315,502.33 mg/kg）, and in Hysacam domestic wastes （54,126.93 mg/kg）. Concentrations of Cd （1.955 mg/kg）, Pb （469.00 mg/kg） and Zn （853.00 rng/kg） are higher in domestic wastes. The ones of Mn （696.96 mg/kg） and Cu （1,320.10 mg/kg） are higher in industrial wastes. Higher concentrations of Pb and Cu let assume that it is a risk of poisoning relative to these elements around this area. These findings illustrate that lixiviation of dumping wastes has great influence on water and soils pollutions of the study ecosystem.
