In the early Eighties, when the lead-in-petrol scandal was breaking and the car industry and the environmentalists had not yet jumped on the bandwagon, the professor lectured me for hours on the evils of the stuff. 'The disinformation campaign being run by the oil industry is worthy of the late Dr Goebbels himself,' was one choice quote.
A petrol industry executive later trotted out the usual 'there's no proof . . .' but almost everything he told me turned out to be claptrap.
Professor Bryce-Smith, now retired, is on the attack again. This time he is among those upbraiding the oil industry for using known carcinogens - such as benzene, toluene and xylene - in unleaded fuel, simply because they are cheap. One form of poison has merely been replaced by another, the professor says.
Some other experts agree that unleaded, in other words, is not as clean as it seems. Dr Simon Wolff of University College London claims that the extra levels of benzenes in unleaded fuel may cause childhood leukaemia. (British unleaded petrol contains up to 3 per cent benzene, American only 1 per cent; the EU limit is 5 per cent.)
The oil industry does not deny that benzene and the other lead substitutes are carcinogenic, but it claims that the level used is within safe limits and there is no firm evidence that the current levels cause cancer - which is what it was saying about lead less than 10 years ago.
One bit of good news: if your car is fitted with a catalytic converter - and new cars now have to be - there is not so much to worry about, because the cat 'converts' most of the carcinogens into harmless gases.
Cars 'converted' to run on unleaded petrol, however, are more problematic. There is now strong evidence that they are no cleaner than when they ran on four-star petrol, never mind what the Government, the car manufacturers, the oil industry, or the environmentalists told motorists several years ago.
THE Chancellor cited environmental reasons for his drastic Budget increase in the price of petrol, with the prospect of more to come in future budgets. But his hope that such revenue will help Britain to reduce its carbon dioxide emissions, as promised in last year's Rio summit, is unlikely to be borne out.
Only a draconian price rise would deter people from using their cars, and Mr Clarke surely knows this would be politically suicidal. So the increase in petrol duty is merely a way of soaking the motorist, who has little alternative but to pay up.
Many drivers will try to save money by cutting down on servicing and maintenance - which leads to higher fuel consumption, which leads to the creation of more carbon dioxide, which leads to more urban pollution.
CARS in Britain, by and large, are not well maintained. That, as much as their sheer volume - and dreadfully out-of-tune diesel buses - is the reason for the rancid air on our high streets. Britain's car-makers know this, and have devised a rather profitable way (for them) of solving the problem: they want to ban cars more than 10 years old.
This is the brainwave of Geoffrey Whalen, Peugeot's chief executive in Britain and head of the motor industry lobbying group, the Society of Motor Manufacturers and Traders. Ford's chief excecutive in Britain, Ian McAllister, agrees. He cites the fact that modern catalyst-equipped petrol cars emit 97 per cent fewer pollutants than those built 10 years ago.
Overtures have been made to the Government, suggesting ways of ridding the streets of such old-timers. The most practical method would be the introduction of a prohibitively expensive MoT test fee for these vehicles. Only the owners of much-loved classic cars - which the society has said it does not want to prohibit - would pay up.
There are a number of problems with the motor traders' approach, quite apart from its tendentiousness (it cites environmental concern, but clearly such a ban would help the car trade shift more new or near-new cars). Old cars do not necessarily pollute more. Poorly maintained cars are the worst polluters, irrespective of their age; roadside pollution monitoring by the RAC has shown that among the worst polluters are year-old non-catalyst cars.
The only way to crack down on poorly maintained cars is to impose much stricter emission tests as part of the annual MoT inspection. The current emissions test - which does not even apply to diesel cars, probably the worst polluters when they get old - is a joke. The limits are absurdly easy, and, if you fail at one test centre, it is usually no big problem to have Old Smoky processed by a less diligent mechanic.Reuse content