EURASIAN JOURNAL OF SOIL SCIENCE, 2015, 4(1): 22-29, Jan 1, 2015
Bulk elements and grain sizes in sediments collected at upstream and downstream of Manwan Dam wer... more Bulk elements and grain sizes in sediments collected at upstream and downstream of Manwan Dam were studied to demonstrate the spatial distribution of heavy metals in the sediments and to assess their risk. Correlation analysis showed that the spatial distribution of Cd, Zn and Mg were significantly affected by dam construction. PCA analysis demonstrate that Cd and Zn were both controlled by Ca, As, Pb, organic matter and clay. Mg was controlled by silt, Al, P and K. The risk assessment demonstrated that the pollution of Cd, As, Zn were more serious than other heavy metals. Fine-grained sediments with higher risk level were found in the section near the upstream of dam, while coarse-grained ones with lower risk level were found in the section far away from the downstream of dam. The sections in tributary were lower in risk than those in the main stream. Heavy metal concentrations in the mainstream sediments were influenced by dam construction and those in tributary were influenced by both dam construction and human activities in locality. Unusual high concentrations of Cd, As, and Zn in both sections implied that more pollution prevention measures are needed in the Manwan Dam in order to prevent increased heavy metal pollutions in the Lancang-Mekong River.
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by environmental degradation, but the sector also has positive impact on society. Since 1930, mineral extraction incomes have been helping to forge socio-economic development in the small nation although
critics argue that the impact is barely felt or seen. Over the years, mineral resources have been the main source of export and direct foreign exchange earning for Sierra Leone. Artisanal and large-scale mining
have provided jobs for thousands of people of Sierra Leone over the past decades. Income from mining especially in rural community’s support livelihood and regulate the local economy in mining communities.
Revenues generated from mining in the form of taxes, exploration fees, environmental impact assessment and monitoring fees, surface rent, license fees and customs taxes among others have help the government in undertaking massive infrastructural development across the country. Mining companies over the years have built schools, clinics, police stations, community centers, bridges, engaged in road maintenance, provide scholarship for outstanding student within the mining communities, support agribusiness ventures, support sporting activities and provided loan to local for business startups as part of their corporate social responsibilities. Nonetheless, improper reporting, corruption, civil war, weak mining policies, inadequate reporting of revenue collected from and lack of transparency prompted public mistrust on benefits of mining in Sierra Leone. It is recommended that revenue generated by mining companies be made public and
corporate social responsibilities (CSR) undertaken be published regularly.
by environmental degradation, but the sector also has positive impact on society. Since 1930, mineral extraction incomes have been helping to forge socio-economic development in the small nation although
critics argue that the impact is barely felt or seen. Over the years, mineral resources have been the main source of export and direct foreign exchange earning for Sierra Leone. Artisanal and large-scale mining
have provided jobs for thousands of people of Sierra Leone over the past decades. Income from mining especially in rural community’s support livelihood and regulate the local economy in mining communities.
Revenues generated from mining in the form of taxes, exploration fees, environmental impact assessment and monitoring fees, surface rent, license fees and customs taxes among others have help the government in undertaking massive infrastructural development across the country. Mining companies over the years have built schools, clinics, police stations, community centers, bridges, engaged in road maintenance, provide scholarship for outstanding student within the mining communities, support agribusiness ventures, support sporting activities and provided loan to local for business startups as part of their corporate social responsibilities. Nonetheless, improper reporting, corruption, civil war, weak mining policies, inadequate reporting of revenue collected from and lack of transparency prompted public mistrust on benefits of mining in Sierra Leone. It is recommended that revenue generated by mining companies be made public and
corporate social responsibilities (CSR) undertaken be published regularly.