Water and Air Pollution Problems

Water and air pollution are the two main factors that destroy the environment in big cities. Paris has no industry, so the Seine is not polluted by industrial effluents but by sewer waters. However, this problem is being solved by building pollution control stations in a Paris suburb. The sewage is channeled into them and cleansed before it goes into the Seine. When visiting these installations, one can often see how pure water the processed water is – the engineers who work there drink it quite cheerfully.

Water is purified by mechanical and biological methods. The purified water is treated with chlorine and released into the rivers, whence it enters the water supply systems where it undergoes further and finer treatment.

Air is mainly polluted by heating systems and cars. When you look at a modern city from a hill top you get the impression of vapour (smog) lingering over the city especially when there are no winds which can air the city. However, when there is no wind they have smog. As regards heating, gas is used rather than coal for last years. The poisoned air is the most modern quarters of the city.

District heating is an effective method. Several heat-and-power plants generate steam, which is piped underground all round the city.

As for cars you know, of course, how heavy traffic is in big cities. The slower the traffic, the more exhaust fumes are. This problem will be solved in the near future.

The acuteness of the problem depends on how well the country is developed and on the number of the cars. Many of these problems are international in nature.