Natural indicators of pollution

Scientists dealing with the problem of pollution consider it very important that it should be exactly assessed. A large number of fairly sophisticated pollution gauges have been devised to serve this purpose. In addition, it has recently been found out that there are a number of natural gauges whose performance by far exceeds anything that has so far been made by man. They are plants such as lichens which are exceptionally sensitive to certain components of air pollution. Ideally such “indicators” species should be widespread, easy to recognize, and between them show a wide range of sensitivity so that the rate of fall-off pollution could be easily assessed. The sensitivity of certain plants to pollution components may also be of value to individual persons contemplating the possibility of settling down in an area. It is known, for example, that lichens are exceptionally sensitive to sulphur dioxide content in the air. It follows that people suffering from a variety of respiratory diseases would do well to live in an area where lichens are abundant on the trees.

7. Answer the following questions to check your understanding of the text:

1. How can pollution be assessed?

2. What do pollution gauges measure?

3. Can anything else be used to measure the air pollution?

4. Why is it important to use natural indicators for measuring pollution?

5. Is it easy to conduct a good pollution survey.

8. Home Assignment. Prepare a five-minute-long paper based on the material of Unit 1 and your home reading and present it at the conference in your group. Work on the recommendations given below:

Recommendations:

1. You should begin with addressing the chairman of the conference and the audience, e.g.

“Mr. Chairman! Ladies and gentlemen! I am greatly honoured to be invited to address this conference”.

2. Then you announce the subject of your paper, e.g.

“I should (would) like to talk in this paper about…”

“The subject of my paper is…”

3. The introduction to your paper may begin like this:

“First of all, I would like to…”

“In the introduction to my paper I should like to…”

“Let me begin with …”

“As many of you know…”

4. After the introduction you make a transition to the body of your paper with the help of the following sentence:

“Now, after a short introduction, I would like to turn to the main part of my paper…”

In the main part you should give the general review of the problem under consideration and then emphasize the most essential details. Here are the phrases used for logical connections of passages within the text:

“First; second; third; next; then; later; afterwards; besides; however; nevertheless; moreover; finally (eventually)”.

“As I have already mentioned…”

“I want to point out that…”

“Allow me to call your attention to…”

“As an example I can suggest…”

5. We recommend you to begin the summery of your paper with the words:

“Now let me review what I have said about”.

And at the end of your presentation do not forget to say:

“Thank you for your attention”.

Requirements:

1. In the paper you should express your opinion about the problem under

consideration. The following phrases may be used:

“In my opinion …”, “To my mind …”, “I think that…”, “I believe that …”, “I consider that …”, “If I’m not mistaken …”

2. The language of your paper should be simple and understandable!

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