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BIOGEOCHEMICAL, HEALTH, AND ECOTOXICOLOGICAL PERSPECTIVES ON GOLD AND GOLD MINING - CHAPTER 12

Asen mối nguy hiểm từ khai thác mỏ vàng cho con người, thực vật và động vật Ô nhiễm Asen của sinh quyển từ khai thác vàng khác nhau và các hoạt động tinh chế gây nguy hiểm cho sức khỏe và hạnh phúc của các cộng đồng sinh học. Phần này các tài liệu nguồn và mức độ thải asen môi trường liên quan với các hoạt động khai thác vàng, rủi ro asen đối với sức khỏe con người, với sự nhấn mạnh vào các thợ mỏ vàng, công nhân nhà máy lọc dầu vàng, và trẻ em cư. | CHAPTER 12 Arsenic Hazards from Gold Mining for Humans Plants and Animals Arsenic contamination of the biosphere from various gold mining and refining operations jeopardizes the health and well-being of biological communities. This section documents the sources and extent of arsenic discharges to the environment associated with gold mining operations arsenic risks to human health with emphasis on gold miners gold refinery workers and children residing near gold mining and refining activities arsenic concentrations in biota and abiotic materials near gold extraction and refining facilities lethal and sublethal effects of different chemical forms of arsenic to representative species of flora and fauna and proposed arsenic criteria for the protection of human health and selected natural resources. 12.1 ARSENIC SOURCES TO THE BIOSPHERE FROM GOLD MINING Gold-bearing ores worldwide contain variable quantities of sulfide and arsenic compounds that interfere with efficient gold extraction using current cyanidation technology. Arsenic occurs in many types of Canadian gold ore deposits mainly as arsenopyrite FeAsS niccolite NiAs cobaltite CoAsS tennantite Cu Fe 12As4S13 enargite Cu3AsS4 orpiment As2S3 and realgar AsS Azcue et al. 1994 . Some gold-containing ores in Colombia South America contain up to 32 of arsenic-bearing minerals and surrounding sediments may hold as much as 6300 mg As kg DW Grosser et al. 1994 . Arsenic enters the environment from a variety of sources associated with gold mining including waste soil and rocks tailings atmospheric emissions from ore roasting and bacterially enhanced leaching. The combination of open-cast mining and heap leaching generates large quantities of waste soil and rock overburden and residual water from ore concentrations tailings . The wastes especially the tailings are rich sources of arsenic Greer 1993 Lim et al. 2003 . In Nova Scotia 221 222 PERSPECTIVES ON GOLD AND GOLD MINING for example about 3 million tons of tailings .