第9章海洋合成有机化合物污染 91海洋合成有机污染物概迷 92海洋有机氯次药污染 9.3海洋多氯联苯污染 94海洋有机磷农药污棨 9.5海洋洗涤剂(磷)污棨
第9章 海洋合成有机化合物污染 9.1 海洋合成有机污染物概述 9.2 海洋有机氯农药污染 9.3 海洋多氯 9.4 海洋有机磷 9.5 海洋洗涤剂（磷）污染
本节课需掌握的主要内容 ●9.1海洋合成有机污染物概述 1.主要的合成污染物种类、代表性物质及 其英文简写
本节课需掌握的主要内容 ⚫ 9.1 海洋合成有机污染物概述 1. 主要的合成污染物种类、代表性物质及 其英文简写；
本节课需掌握的主要内容 ●9.2海洋有机氯农药污染 1.P.P-DDT的光分解反应、微生物降解 反应(脱氯、脱卤化氢作用)方程式, P52-53
本节课需掌握的主要内容 ⚫ 9.2 海洋有机氯农药污染 1. P，P′- DDT的光分解反应、微生物降解 反应（脱氯、脱卤化氢作用）方程式， P52-53
Pesticide dilemma ASI NOR ITH AMERICA EUROPE ATLANTIC OCEAN PACIFIC OCEAN AFRICA'4 INDIAN OCEAN SOUTH AUSTRALIA 303s AMERICA 3000 Mies Malaria has been eradicated or never existed 60s 80s Malaria poses a limited risk Malaria is common Because of the efficacy of ddt in checking malaria and other mosquito borne diseases (yellow fever, encephalitis) it is estimated that more than 75 million deaths have been averted
Pesticide Dilemma Because of the efficacy of DDT in checking malaria and other mosquito borne diseases (yellow fever, encephalitis), it is estimated that more than 75 million deaths have been averted
Pesticide characteristics Pesticides are toxins used against organisms that interfere with human activities or welfare Pesticides are grouped according to the pests they target-insecticides kill insects, herbicides kill plants, fungicides kill fungi, and rodenticides kill rats and mice Agriculture uses 85% of the almost 3 millions tons of pesticides used each year
Pesticide Characteristics Pesticides are toxins used against organisms that interfere with human activities or welfare. Pesticides are grouped according to the pests they target – insecticides kill insects, herbicides kill plants, fungicides kill fungi, and rodenticides kill rats and mice. Agriculture uses ~85% of the almost 3 millions tons of pesticides used each year
Pesticide characteristics Many plant-derived pesticides(e.g, pyrethrin from chrysanthemums)or their derivatives are easily broken down by microorganisms and do not persist long in the environment Most of the second generation man-made pesticides (e.g., DDT)are broad spectrum and slow to degrade(half-life 15 years in soil and as much as 150 years in aquatic environments)
Pesticide Characteristics Many plant-derived pesticides (e.g., pyrethrin from chrysanthemums) or their derivatives are easily broken down by microorganisms and do not persist long in the environment. Most of the second generation man-made pesticides (e.g., DDT) are broad spectrum and slow to degrade (half-life 15 years in soil and as much as 150 years in aquatic environments)
Pesticide risks Pesticides can kill desirable organisms as well as pests. For example, broad spectrum insecticides may kill pollinators such as bees or lady bugs, which eat garden aphids Pesticides enter the food network and through biological magnification may concentrate to toxin levels in secondary and tertiary consumers
Pesticide Risks Pesticides can kill desirable organisms as well as pests. For example, broad spectrum insecticides may kill pollinators such as bees or lady bugs, which eat garden aphids. Pesticides enter the food network and through biological magnification may concentrate to toxin levels in secondary and tertiary consumers
Pesticide Benefits Disease control -e.g, malaria caused by female Anopheles mosquitoes Crop protection -reduce loss from competition with weeds, consumption by insects, and disease caused by fungi and bacteria. Part of reason for large numbers of agricultural pests is emphasis on monoculture in large tracts of land
Pesticide Benefits Disease control - e.g., malaria caused by female Anopheles mosquitoes. Crop protection - reduce loss from competition with weeds, consumption by insects, and disease caused by fungi and bacteria. Part of reason for large numbers of agricultural pests is emphasis on monoculture in large tracts of land
Effects of Long 500. Term Use of E400 Pesticides 00 Insect pest Insect predator or parasite 100 195019601970198019902000 Natural population fluctuations Pesticide application Tt
Effects of Long Term Use of Pesticides
Effects of Long Term Use of Pesticides In addition to selection for pests with genetic resistance long term use of pesticides causes imbalances in ecosystemS. Beneficial organisms and even natural enemies of the pests may be among the species 1400 1.300 eliminated by pesticides. May lose 1,100 1.000 keystone species. May develop new 800 DDT treated trees dominant pest species Untreated control trees 50 ∠ conomic injury leve 1967
Effects of Long Term Use of Pesticides In addition to selection for pests with genetic resistance, long term use of pesticides causes imbalances in ecosystems. Beneficial organisms and even natural enemies of the pests may be among the species eliminated by pesticides. May lose keystone species. May develop new dominant pest species