Phân tích của ý nghĩa chủ đề môi trường chính Bởi vì thuốc trừ sâu kỵ nước có xu hướng liên kết với các hạt bụi và các chất hữu cơ, họ có thể được tìm thấy trong trầm tích giường và sinh vật thủy sản ngay cả khi họ không phát hiện trong các mẫu nước từ hệ thống thủy văn. Vì vậy, phát hiện trong trầm tích giường và sinh vật thủy sản phục vụ như là một dấu hiệu cho thấy các hợp chất này là chất gây ô nhiễm trong hệ thống thủy văn. Rõ ràng, các. | CHAPTER 6 Analysis Of Key Topics Environmental Significance Because hydrophobic pesticides tend to associate with particulates and organic matter they may be found in bed sediment and aquatic biota even when they are not detectable in water samples from the same hydrologic system. Thus their detection in bed sediment and aquatic biota serves as an indicator that these compounds are present as contaminants in the hydrologic system. Clearly the monitoring studies reviewed Tables and indicate that many pesticides are frequently found in these media in rivers and streams of the United States. Yet what is the significance of these residues to biota that live in or are dependent on the hydrologic systems As noted in Chapter 4 organisms in the water column and in sediment may be exposed to pesticides in the dissolved form or in association with colloids or particulates or by ingestion of contaminated food or particulates. Pesticide-contaminated fish may be consumed by both wildlife and humans thus reintroducing the pesticide into the terrestrial environment. These exposures thus result in the potential for adverse effects on ecosystems and human health. The potential effects of hydrophobic pesticides on aquatic organisms and fish-eating wildlife and on human health are discussed in Sections and respectively. EFFECTS OF PESTICIDE CONTAMINANTS ON AQUATIC ORGANISMS AND FISH-EATING WILDLIFE A review of the toxicity of organochlorine and other hydrophobic contaminants to fish other aquatic organisms and wildlife is beyond the scope of this book. The literature in this area is voluminous . . Environmental Protection Agency 1975 Eisler 1985 1990 Eisler and Jacknow 1985 Murty 1986a b . For example DDT has been shown to adversely affect a variety of organisms from phytoplankton to fish-eating birds and mammals. In a report supporting its decision to ban DDT . Environmental Protection Agency USEPA reviewed the adverse effects of DDT on fish and wildlife
