DDT ( Dichloro Diphenyl Tricoloroethane )
It is clear that some chemicals can damage the health of animals and humans. However, this is not the only problem that can be caused by the careless use of chemicals. Chemicals can also disturb the ecological balance of the environment. If the ecological balance is  disturbed, the consequences can be extremely serious.

( Dichloro Diphenyl Tricoloroethane )

The history of DDT  illustrates this problem. DDT, a chemical which kills insects, at first seemed to be a perfect answer to many problems. It would control insects that caused dangerous diseases, as well as insects that caused billions of dollars of damage to crops every  year.

( Dichloro Diphenyl Tricoloroethane )

About DDT
What is DDT

 

Governments permitted and even encouraged the use of DDT. Farmers in many countries began to spray it on their crops. The immediate results were good: damage to crops went down, and profits went up. However, the chemical had effects which the scientists had not predicted.

First, it also killed insects which were the natural  enemies of the harmful insects and which were, therefore, beneficial to farmers. Second, and perhaps worse, DDT did not kill every harmful insect. A few insects, which had natural resistance to the chemical, survived and multiplied.

In a few years, there were large numbers of insects which were not affected by DDT, and there were  fewer insects which could act as natural controls on these new* ‘super-insects’.

Finally, it became clear that DDT was not solving the insect problem. In fact, it was making the problem worse. It then became necessary to find a second cure for the effects of the first!

Pictures of insects
Insect Pictures

Questions about  Dichloro Diphenyl Tricoloroethane
Mark the best choice.

1. Line 6, this problem’ refers to .

a) chemicals damaging the health of animals and humans

b) the careless use of chemicals

c) chemicals’ disturbing the ecological balance of the environment

d) the extremely serious consequences

Diphenyl
Dichloro Diphenyl Tricoloroethane

2. DDT was first viewed favourably because .

a) it helped control certain diseases and crop damage

b) all its effects were predictable

c) its use was encouraged by governments

d) it did not harm humans or animals

 

3. Scientists couldn’t realise that .

a) the use of DDT would increase the agricultural profits

b) DDT would also kill certain insects which were useful

c) the type of insects which DDT destroyed would later grow a resistance

d) the immediate results of DDT usage would be good

 

4. If a farmer used DDT today, in five years’ time .

a) he would have no problems with harmful insects

b) his situation would not be different

c) insects might create an even greater problem for him

d) his profits would eventually rise to unexpected levels

In this article you have found information about ( Dichloro Diphenyl Tricoloroethane )

 

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