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Phân Tích Hiện chủ đề chính-nguồn, hành vi, và Giao thông vận tải Các tổng quan trước phân phối quốc gia và xu hướng của thuốc trừ sâu trong trầm tích giường và sinh vật thủy sản, và điều chỉnh các yếu tố ảnh hưởng đến nồng độ của họ trong các phương tiện truyền thông, để lại nhiều câu hỏi cụ thể chưa có ai trả lời. Hai chương kế tiếp vẽ trên thông tin trong các tài liệu xem xét thảo luận, cụ thể, một số chủ đề quan trọng liên quan đến thuốc bảo vệ thực vật trong. | CHAPTER 5 Analysis Of Key Topics Sources Behavior And Transport The preceding overviews of national distribution and trends of pesticides in bed sediment and aquatic biota and of governing factors that affect their concentrations in these media leaves many specific questions unanswered. The next two chapters draw on information in the literature reviewed to discuss in detail several important topics related to pesticides in bed sediment and aquatic biota. Each key topic falls into one of two categories 1 sources behavior and transport Chapter 5 or 2 environmental significance Chapter 6 . 5.1 EFFECT OF LAND USE ON PESTICIDE CONTAMINATION The terrestrial environment has a strong influence on the water quality of adjacent hydrologic systems. Both natural and anthropogenic characteristics of the terrestrial environment are important. For example concentrations of major chemical constituents such as sulfate calcium and pH in a hydrologic system are influenced by geology and the concentration of suspended sediment is influenced by soil characteristics topography and land cover. Land use activities such as row crop agriculture pasture forestry industry and urbanization also can affect adjacent water bodies. Any pesticide associated with a land use can potentially find its way to the hydrologic system and if the pesticide has persistent and hydrophobic properties see Section 5.4 it will tend to accumulate in bed sediment and aquatic biota. The following section addresses the observed link between land use and the detection of pesticides in bed sediment and aquatic biota. Four types of land use will be discussed agriculture forestry urban areas and industry and remote or undeveloped areas. In many cases forested areas also could be described as remote or undeveloped areas. The critical distinction here however is that many forested areas have been managed with the use of pesticides whereas remote and undeveloped areas have not. 5.1.1 AGRICULTURE By far the largest use of .
