Problems and Concerns caused by Human Influences on the Environment

Traffic

Large cities always have a traffic problem. Cars and lorries burn petrol which produces pollutants such as sulphur dioxide, carbon monoxide and lead. oxides. The sulphur dioxide reacts with the moisture in the atmosphere to produce a weak acid solution. This acid erodes the stones, such as sandstone and limestone, which are used to make buildings.

Many of the ancient monuments of Athens and Rome which have survived over thousands of years are now suffering from the erosion caused by pollutants in the air.

Carbon monoxide is harmful to the human body because it takes the place of oxygen in the blood. Lead is also a dangerous chemical; once it is inside the body it cannot be removed. It accumulates in the body in organs such as the brain. Too much lead in the body causes lead poisoning which can be fatal.

Many countries have passed the laws to ensure that all new cars can use only lead-free petrol. City councils are considering ways in which to limit the numbers of cars allowed in the big cities, in an attempt to reduce the pollution.

FACT 1

There are over 500 million registered automobiles (cars, lorries etc.) on Earth. Filling their petrol tanks uses one third of the world's production of oil. It is estimated that the number of automobiles will have reached 2 billion by the year 2025.

• Problems and Concerns Homepage
• Human Influences on the Environment Homepage
• Questions relating to this chapter
• Top of Page

© Paul Billiet, Shirley Burchill, Alan Damon and Deborah James 2009