CHAPTER 3 Chương này sẽ xem xét các quá trình xác định độc tính of the chất ô Nhiệm Hữu cơ to the sinh vật sống. Thuật ngữ "độc tính" sẽ bao gồm the affect có hai nói chung and will not bị limit to give chết. With the tiến bộ nhanh chong trong cơ chế độc tố trong the năm gần đây, Càng ngày cang có thể hiệu be trình tự cơ bản of the thay đổi dẫn đến sự xuất hiện của triệu Certificate Nhiệm độc và làm thế nào sự khác biệt trong hoạt động of the quá trình. | CHAPTER 3 Influence of the properties of chemicals on their environmental fate Introduction The previous chapter was concerned with the processes that determine the distribution of chemicals within living organisms and with the relationship between distribution and toxicity. The importance of the properties of chemicals in determining their fate within living organisms was given emphasis. Polarity molecular size the presence of functional groups and molecular stability were all seen to influence toxicokinetic processes. The types of enzymes responsible for biotransformations were related to the structures of the chemicals undergoing biotransformation . esterases for esters reductases for nitro compounds monooxygenases for aromatic hydrocarbons . The present chapter will consider the wider question of how the properties of chemicals determine their fate in the gross environment and how these properties can be incorporated into descriptive and predictive models relating to the movement and distribution of environmental chemicals. First there will be a description of chemical and physical properties that determine the fate of organic pollutants in the gross environment restricting the discussion to chemical and physical processes. Next there will be an account of how these data are incorporated into models that attempt to describe or predict environmental fate. Finally 2001 C. H. Walker Environmental fate of chemicals 65 the relationship will be discussed between the properties of chemicals and the operation of biological processes that determine environmental fate. Drawing on the background given in the previous chapter emphasis will be given to the relationship between the properties of environmental chemicals and their uptake excretion and metabolism. The overall aim will be to lay a proper foundation for consideration of more complex issues in Chapter 4 which will address the question of the movement and distribution of chemicals in ecosystems where both .
