tailieunhanh - Introduction to ENVIRONMENTAL TOXICOLOGY Impacts of Chemicals Upon Ecological Systems - CHAPTER 11

Đánh giá rủi ro sinh thái GIỚI THIỆU Một số lượng lớn độc tố môi trường được thực hiện với mục tiêu cuối cùng thực hiện một đánh giá rủi ro. Một số lượng lớn các nghiên cứu được thực hiện trong lĩnh vực này là hướng tới việc xác định nguy cơ sản xuất một sản phẩm mới hoặc phát hành một trừ sâu, nước thải đối với môi trường. Do sự tương tác giữa chất độc môi trường và đánh giá rủi ro, một sự hiểu biết cơ bản và rõ ràng về đánh giá rủi ro sinh thái. | CHAPTER 11 Ecological Risk Assessment INTRODUCTION A great deal of environmental toxicology is performed with the eventual goal of performing a risk assessment. A great deal of the research performed in the field is geared toward the determination of the risk of producing a new product or releasing a pesticide or effluent to the environment. Because of the interaction between environmental toxicology and risk assessment a basic and clear understanding of ecological risk assessment in necessary. Appendix B contains a reprint of the recent . EPA document A Framework for Ecological Risk Assessment . This document is a relatively clear review of the basics of ecological risk assessment as percieved in the early 1990s. Since the original publication of this framework additional case studies and a guidance document have been published . EPA 1993 1996 . This chapter reviews the structure of ecological risk assessment and introduces some current developments. The latter sections also provide a suggested approach for the risk assessment of wide-area sites with multiple stressors. Two points should be considered carefully as regards the relationship between environmental toxicology and risk assessment. First environmenal toxicology should not be seen as dependent upon risk assessment as its justification. Risk assessment is a management tool used for making decisions often with a great deal of uncertainty. The science of environmental toxicology as with any science attempts to answer specific questions. In the case of environmental toxicology the question is primarily how xenobiotics interact with the components of ecological systems. Second risk assessment is not a strictly scientific pursuit. The assessment endpoints of risk assessment are often set by societal perceptions and values. Although the scientific process may be used in the gathering of information in the assignment of risks unless a testable hypothesis can be formulated the scientific method is not being