Many years ago people lived in harmony with the environment because industry was not much developed. Now the situation is quite different.

People all over the world cannot ignore the problem of the protection of the environment because of modem industry and the need for energy.

Newspapers and magazines write a lot about water pollution, air pollution and land pollution. There are some laws and decisions on this important question. There are state organisations and international conventions which pay much attention to this problem.

Many parts of the world are crowded now, much of our waste, especially waste from factories, electric power stations, the chemical industry and heavy industry are very dangerous. Fish dies in the lakes, rivers and seas, forest trees die too.

The problem of radiation has also become a very important problem because it is very dangerous for health of people.

There is a science, named ecology, which study the relation between people and their environment. But each of us also must do everything possible to keep our environment clean for ourselves and for the next generations.