1. Translate and memorize the following words.

accumulate	injurious	intestines
pile up	poisonous	stomach
influence smth	thyroid	skin
get into	respiratory	kidney
take out	digestive	muscle
oppress	nervous	brain
injure	harmful	hormone
contaminate	contaminant	health

2. Read and translate correctly:

organ, organism, blood system, bone, skeleton, hormone, throat, lungs, heart, liver, digestion, respiratory system, digestive system, hormone system, reproductive system, heavy metal compound, injurious, to accumulate smth, to pile up, to concentrate in, to influence smth, to affect smth./smb.

3. Find the pairs of synonyms.

accumulate, give off, take out, bone system, harmful, concentrate, bring out, adverse, deplete, injurious, skeleton, weaken, emit.

4. Read correctly and translate the name of the elements and substances given in the picture.

5. Divide the substances into four groups: a) heavy metals; b) heavy metal compounds; c) gases; d) organic compounds. Comment your choice.

Model: Lead belongs to the group of heavy metals. Ammonia is included in the group of harmful gases.

lead, mercury, fluorine, plumbum oxide, formalehyde, nickel, cadmium, arsenic, fluoride, organic lead, sulphur dioxide, plumbum, nickel carbonyl, carbon oxide, mercaptane, methane, ozone.

6. Answer the questions. Pay attention to the Passive Voice.

1. Where are heavy metal compounds accumulated?

2. What organs and systems does lead (CO, mercury) get into?

3. Where can chromium (fluoride) be concentrated in?

4. What organs contain nickel (cadmium, arsenic)?

5. What systems and organs does CO (vanadium) influence?

6. What substances are concentrated in the nails, hair and skin?

7. What compounds are hardly removed from the organizm?

8. What substances tends to be accumulated in the human body?

7. Make up sentences with new words and expressions. Pay attention to prepositions.

8. Describe the picture. Begin with the phrase « As it is shown in the picture ...» or « As I've learnt from the picture...»

9. Read and understand this text. Answer the questions below. Air Pollution

Pollution is of great concern to both science, industry and to humanity as a whole.

There has always been pollution, even when man was not present. When man appeared upon earth, he added much to the pollution through the industrial activity, and through man's use of devices such as automobiles that cause pollution.

Every smoking chimney is a source of air pollution. The use of natural gas or oil that have a negligible mineral content is of great help in reducing pollution, but has the disadvantage of rapidly consuming materials which could better be conserved for future generation as raw materials for the manufacture, for example, chemicals and plastics.

It has been found that some chemical processes, such as the manufacture of lime, Portland cement, steel, give off much dust.

Lead, bromide and chloride are emitted by the automobiles which burn lead-containing gasoline. A lead-chloride-bromide aerosol is exhausted in great amounts nowadays.It is considered to be a common air contaminant in urban areas. It has been long found out that such aerosol is toxic to people and has prolonged negative effect as it’s hardly taken out from the organism.

The oxides of sulphur, oxides of nitrogen, carbon monoxide as well as incompletely burned hydrocarbons are included to the group of chief atmospheric gaseous pollutants.

It is stated that these gases react with energy from sunlight and produce photochemical smog. Smog not only can be highly irritating to eyes and lungs, but it can also cause extensive damage to vegetation.

City air is polluted not only by exhaust fumes but also by the products of their oxidization, often much more toxic than the initial substance. One of them is ozone which is useful only in small quantities, but is deadly poisonous in large concentrations.