1. The word 'petroleum' comes from the Latin phrase petra oleum. The word petra means 'rock' and oleum means 'oil'. Thus 'petroleum' means oil that forms underground and is obtained from wells sunk into the ground.
2. Petroleum and its products are of great importance to modern life. These products include gasoline (petrol), kerosene (paraffin), diesel oil, fuel oil, lubricants, bitumen, and wax. No industrialist can do without them. Petrol is used in motor cars. Kerosene is used in oil lamps. Diesel oil is used in diesel engines for buses, lorries and ships. Fuel oil is burned to make steam in the boilers of steam ships and in furnaces of many kinds, such as used in the manufacture of steel, glass and pottery. Lubricants are the oils and greases needed to make machinery of any kind run smoothly and easily. Bitumen is used in asphalt (a black sticky substance used for making roads).
3. Petroleum was probably formed from dead plants and animals life of the seas. The dead remains decayed on the seabed until only fatty and oily substances were left. These substances became buried under mud as time went on; the mud was squeezed into a layer of rock, while the oily substances were changed into petroleum and gas.
4. The oil seldom remained in the rock where it was formed. Sometimes it travelled many miles through pores in the rock until it met a hard, non-porous rock which it could not get through. Here, trapped beneath a cap of non-porous rock, the oil can be found contained in the lower surface, like water in a sponge. Only drilling can prove that oil exists in a particular place.
5. Pollution is the fouling of the environment- land, water and air- by waste, smoke, chemicals and other harmful substances. The most serous pollution occurs where there are large cities and many factories. Every industrial country faces the problem of waste. As factories produce new goods for people to buy, old ones are thrown out with household rubbish. Burning this refuse pollutes the air, dumping it in rivers and seas pollutes the water, and rubbish tips are unpleasant sights and take up much needed space. Getting rid of plastics is particularly difficult. Wood and paper decay after some time through the action of bacteria. But plastics never decay. The more we throw away, the more litter is produced.
6. The world's oceans have been used as 'dustbins', with millions of tonnes of rubbish being dumped into the sea every year, harming marine life. If too much untreated sewage is poured into seas, lakes, and rivers through sewers, water can no longer dilute it. All the oxygen in the water is used up, and the fish die. The bacteria which normally break down the sewage into harmless substances also die, only harmful bacteria which do not need air remain, and these cause disease.
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