Spelling out dangers of ozone

Daily Telegraph, 4 June 1991:

Government plans to revitalise the railways (report, May 29) have not come too soon. Ministers talk vaguely of vehicle pollution but seldom specify the extent to which motor vehicles damage human health and degrade the environment.

One of the chief culprits is ground level ozone, formed when sunlight acts upon vehicle pollutants, such as oxides of nitrogen and hydrocarbons. Ozone is a powerful respiratory irritant, and commonly exceeds World Health Organisation guidelines in parts of Britain. At low levels it is known to affect plant growth and reduce crop production, and has been incriminated as one of the main causes of forest damage in Central Europe and the dying of trees in the UK.

The tragedy is that ozone pollution will grow worse. Information from the Department of Transport — where, incidentally, more than 90 per cent of the civil servants are assigned to roads — shows that the number of cars in Britain has increased from two million in 1951 to 18 million in 1988, and is set to increase by between 80 to 150 per cent by the year 2025.

While some of this increase will be mitigated by the introduction of catalytic converters on new cars, there is little prospect of an improvement in air quality. Moreover, the continued thinning of the ozone layer within the stratosphere means that Inore short wavelength ultraviolet light (UVB) will reach the lower atmosphere, leading to more production of ground level ozone.

Road vehicles are also a major contributor to global warming. In Britain, transport accounts for 22 per cent of carbon dioxide production, and further increases from traffic growth will not be offset by the use of catalysts.

Ozone itself is a powerful greenhouse gas, and contributes as much as 10 per cent as a percentage of global warming due to carbon dioxide alone. All of these effects — ground-level ozone, increasing UVB and global warming — will have a deleterious impact on agricultural production. In addition, vehicle emissions make a significant contribution to the acidification of soils by acid rain. Sir Crispin Tickell recently warned of an impending ecological disaster, global in its manifestations, which would not spare the industrialised nations. With unrestrained growth in car usage worldwide, it requires little imagination to foresee how that disaster is going to occur.

Royal Postgraduate Medical School
London W12