tailieunhanh - Introduction to ENVIRONMENTAL TOXICOLOGY Impacts of Chemicals Upon Ecological Systems - CHAPTER 10

Đo lường và Giải thích các hiệu ứng sinh thái của chất độc GIỚI THIỆU Chương này đề cập chủ đề này có lẽ khó khăn nhất trong độc học môi trường, làm thế nào để đo lường và sau đó đánh giá tác động của chất độc ở các cấp độ sinh thái của tổ chức. Chương này bắt đầu với một đánh giá các phương pháp và kết thúc bằng một cuộc thảo luận về phản ứng của các hệ sinh thái căng thẳng hóa chất. Đo lường tác động sinh thái CÁC CẤP CỦA TỔ CHỨC SINH HỌC Biomonitoring. | CHAPTER 10 Measurement and Interpretation of the Ecological Effects of Toxicants INTRODUCTION This chapter deals with perhaps the most difficult topic in environmental toxicology how to measure and then evaluate the impact of toxicants at ecological levels of organization. The chapter starts with an evaluation of methods and ends with a discussion of the responses of ecosystems to chemical stressors. MEASUREMENT OF ECOLOGICAL EFFECTS AT VARIOUS LEVELS OF BIOLOGICAL ORGANIZATION Biomonitoring is a term that implies a biological system is used in some way for the evaluation of the current status of an ecosystem. Validation as to the predictions and protections derived from the elaborate series of tests and our understanding presented in previous chapters can only be done by effective monitoring of ecosystems Landis 1991 . In general biomonitoring programs fall into two categories exposure and effects. Many of the traditional monitoring programs involve the analytical measurement of a target compound with the tissue of a sampled organism. The examination of pesticide residues in fish tissues or PCBs in terrestrial mammals and birds are examples of this application of biomonitoring. Effects monitoring looks at various levels of biological organization to evaluate the status of the biological community. Generically effects monitoring allows a toxicologist to perform an evaluation without an analytical determination of any particular chemical concentration. Synergistic and antagonistic interactions within complex mixtures are integrated into the biomonitoring response. In the biomonitoring process there is the problem of balancing specificity with the reliability of seeing an impact Figure . Specificity is important since it is crucial to know and understand the causal relationships in order to set management or cleanup strategies. However an increase in specificity generally results in a focus 1999 by CRC Press LLC Biomonitoring Tug of War - Specificity Attributing