The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory te...The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory testing.The results show that the methyl mercury contents in water,sediment and soil in gold-mining areas are much higher than those in the control site,indicating that gold-mining activities intensify the methyl mercury pollution in the study area.Methyl mercury contents are in a descending order of sediment > soil > water in the environment,and in a descending order of brain > viscera > muscle > skin in Rana chensinensis.There are significant correlation between methyl mercury contents in Rana chensinensis and those in water and sediment.In particular,the methyl mercury content in the skin of Rana chensinensis is positively correlated with those in water and sediment in spring.Therefore,skin is one of main intake pathways for methyl mercury due to its high permeability.展开更多
Land tenure is a major determinant of the types of land use in a region or area and, by extension, affects its conservation. Most of the land that falls under public or communal land-tenure systems in developing count...Land tenure is a major determinant of the types of land use in a region or area and, by extension, affects its conservation. Most of the land that falls under public or communal land-tenure systems in developing countries such as Mali faces numerous challenges among them being natural resource overexploitation. This is mainly because the land is openly accessible to all people around it, and thus the tendency to overexploit the land resources leading to degradation, and food and environmental insecurity. In Mali, land ownership falls under three categories: Public or Government, Communal and Private. This study was undertaken to assess the land ownership types in Yanfolia District, Mali, a gold-mining area that lies some 170 km southern east of capital district of Bamako and upstream of Selingué dam on Sankarini River. A social survey of 200 households was done using a structured questionnaire. Additional research instruments were focus group discussion, key informant interviews and observation check-lists. The data was analyzed using both descriptive and inferential statistics. The study findings indicated that most of the land under gold-mining was owned by the government followed by community and finally private. There were significant associations between size of land under gold-mining and land tenure types: communal land (<em>χ</em><sup>2</sup> = 30.52;p = 0.000);private land (<em>χ</em><sup>2</sup> = 65.09;p = 0.000) and public or government land (<em>χ</em><sup>2</sup> = 177;p = 0.000). Gold-mining takes place mostly on lands classified under public/government and communal compared to that which takes place on lands classified as private. It is recommended that the relevant Malian governmental regulatory and enforcement agencies implement and enforce existing environmental laws with respect to land and environment. These agencies should adopt participatory and sustainable approaches to land and natural resources management for improved food and environmental security.展开更多
基金Under the auspices of National Natural Science Foundation of China (No. 40673059)Testing Foundation of Northeast Normal University
文摘The distribution characteristics of methyl mercury in Rana chensinensis and water,sediment and soil in gold-mining areas of the upper reaches of the Songhua River,China were studied by field sampling and laboratory testing.The results show that the methyl mercury contents in water,sediment and soil in gold-mining areas are much higher than those in the control site,indicating that gold-mining activities intensify the methyl mercury pollution in the study area.Methyl mercury contents are in a descending order of sediment > soil > water in the environment,and in a descending order of brain > viscera > muscle > skin in Rana chensinensis.There are significant correlation between methyl mercury contents in Rana chensinensis and those in water and sediment.In particular,the methyl mercury content in the skin of Rana chensinensis is positively correlated with those in water and sediment in spring.Therefore,skin is one of main intake pathways for methyl mercury due to its high permeability.
文摘Land tenure is a major determinant of the types of land use in a region or area and, by extension, affects its conservation. Most of the land that falls under public or communal land-tenure systems in developing countries such as Mali faces numerous challenges among them being natural resource overexploitation. This is mainly because the land is openly accessible to all people around it, and thus the tendency to overexploit the land resources leading to degradation, and food and environmental insecurity. In Mali, land ownership falls under three categories: Public or Government, Communal and Private. This study was undertaken to assess the land ownership types in Yanfolia District, Mali, a gold-mining area that lies some 170 km southern east of capital district of Bamako and upstream of Selingué dam on Sankarini River. A social survey of 200 households was done using a structured questionnaire. Additional research instruments were focus group discussion, key informant interviews and observation check-lists. The data was analyzed using both descriptive and inferential statistics. The study findings indicated that most of the land under gold-mining was owned by the government followed by community and finally private. There were significant associations between size of land under gold-mining and land tenure types: communal land (<em>χ</em><sup>2</sup> = 30.52;p = 0.000);private land (<em>χ</em><sup>2</sup> = 65.09;p = 0.000) and public or government land (<em>χ</em><sup>2</sup> = 177;p = 0.000). Gold-mining takes place mostly on lands classified under public/government and communal compared to that which takes place on lands classified as private. It is recommended that the relevant Malian governmental regulatory and enforcement agencies implement and enforce existing environmental laws with respect to land and environment. These agencies should adopt participatory and sustainable approaches to land and natural resources management for improved food and environmental security.
