Insecticide
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An insecticide is a pesticide whose purpose is to kill or to prevent the multiplication of insects.
Insecticides are very widely used in agriculture, as well as in people's dwellings and workplaces. The use of insecticides is one of the major causal factors behind the increase in agricultural productivity in the 20th century.
Various plants have been used as folk insectides for centuries, including tobacco and pyrethrum.
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Environmental Effects
Some insecticides have been banned due to their adverse effects on animals or humans. Misuse of insecticides is a major factor in pollinator decline.
DDT is an example of a heavily used and misused pesticide. One of the better known impacts of DDT is to reduce the thickness of the egg shells on predatory birds. The shells sometimes become too thin to be viable, causing reductions in bird populations. This occurs with DDT and a number of related compounds due to the process of bioaccumulation, wherein the chemical, due to its stability and fat solubility, accumulates to progressively higher concentrations in the body fat of animals farther up the food chain. The near-worldwide ban on agricultural use of DDT and related chemicals has allowed some of these birds--such as the peregrine falcon--to recover in recent years.
Despite these positive results of the reduction of DDT utilization, opponents of environmentalism often erroneously cite it as an example of environmentalism going too far and interfering with malaria eradication, going so far as to estimate the number of human lives resulting from the DDT ban; for instance, Michael Crichton states in his bestselling book, State of Fear:
- "Since the ban, two million people a year have died unnecessarily from malaria, mostly children. The ban has caused more than fifty million needless deaths. Banning DDT killed more people than Hitler."
The reasoning behind this accusation is demonstrably erroneous, however, because there is in fact no ban whatsoever on use of DDT for eradication of malaria or any other insect borne disease.[1] () Groups fighting malaria have praised the ban on agricultural use of DDT, since it reduces the rate with which mosquitos become resistant to DDT, which is the real reason it is not used more often to fight malaria:
- "The outcome of the treaty is arguably better than the status quo going into the negotiations over two years ago. For the first time, there is now an insecticide which is restricted to vector control only, meaning that the selection of resistant mosquitoes will be slower than before." [2] ().
In fact, according to Agricultural production and malaria resurgence in Central America and India, Chapin, Georgeanne & Robert Wasserstrom, Nature, Vol. 293, 1981, page 183), the lives actually saved due to banning agricultural use of DDT can be estimated:
- "Correlating the use of DDT in El Salvador with renewed malaria transmission, it can be estimated that at current rates each kilo of insecticide added to the environment will generate 105 new cases of malaria."
Some of the newer insecticides are more specific in their actions and are designed to break down into non-toxic components within a few days of application.
Individual insecticides
Chlorinated
Several are now banned because of their ecological persistence:
Organophosphorus
Chemically similar to Nerve agents
Plant toxin derived
Others
Branded products
- Black Flag ®
- Gaucho ®
- Regent ®
- Merit ®
See also
de:Insektizid fr:Insecticide nl:Insecticide sr:Инсектициди ja:殺虫剤 pl:Insektycyd sr:Инсектициди