Đang chuẩn bị liên kết để tải về tài liệu:
Ebook: Assessing the Hazard of the Metals and Inorganic Metal Substances in Aquatic and Terrestrial Systems - Chapter 5

Chương này diễn tả độc tính, cụ thể, phát sinh từ tác hại của việc tiếp xúc với kim loại và kim loại sinh vật các chất vô cơ (gọi chung là kim loại). Trọng tâm của chương này là môi trường nước, nó xem xét tiếp xúc từ cột nước, từ trầm tích, và từ ăn phải thực phẩm hoặc trầm tích. Tiếp xúc với động vật hoang dã trên cạn IS Được coi là riêng rẽ trong Chương 6. Để cho phép thành lập công ty độc tính vào bảng xếp hạng dựa trên rủi ro, ưu tiên,. | 5 Aquatic Toxicity for Hazard Identification of Metals and Inorganic Metal Substances Andrew S. Green Peter M. Chapman Herbert E. Allen Peter G.C. Campbell Rick D. Cardwell Karel De Schamphelaere Katrien M. Delbeke David R. Mount and William A. Stubblefield 5.1 INTRODUCTION This chapter deals with toxicity specifically harmful effects arising from exposure of biota to metals and inorganic metal substances collectively referred to as metals . The focus of this chapter is the aquatic environment it considers exposure from the water column from sediment and from ingestion of food or sediment. Exposure of terrestrial wildlife is considered separately in Chapter 6. To allow incorporation of toxicity into risk-based ranking prioritization and screening assessments referred to as categorization there must be a means of aggregating toxicological data into a form that effectively expresses the toxicological potency of metals. The aggregation of metals toxicity data must be sensitive to issues affecting their quality applicability and interpretation. There are many factors that affect metal toxicity the most important being chemical speciation and bioavailability. In addition to these 2 key factors the following considerations apply In many regulatory assessments there is great focus on the most sensitive organisms or end points in an effort to preclude environmental risks. For categorization rather than risk assessment the approach should not strictly be as conservative as possible but rather as comparable as possible because the goal is to rank relative hazard or risk across different substances including metals. Though metals occur in many forms their toxicity is expected to relate to a very few dissolved chemical species primarily the free metal ion. 89 2007 by the Society of Environmental Toxicology and Chemistry SETAC 90 Assessing the Hazard of Metals and Inorganic Metal Substances Evaluation of metal toxicity data is therefore centered on characterizing 1 dissolution