For interest sake...
As you are aware, we have been told that our old cars must go because of their 'dirty' exhausts, in particular the lead issuing forth and causing great public health problems.
Dr David Warren was the guest speaker at the quarterly meeting of the AOMC (Vic) on 28 February 1994. Dr Warren is a retired Research Scientist for the Department of Defence and was the Energy Resources adviser to the Victorian Government back in the early/mid-'80s when the ULP debate was gathering momentum. Here is a condensed summary of Dr Warren's address.
ENTER LEAD
"In the early 1920s, a fellow called Thomas Midgie was looking for something to combine with the free radicals to stop 'knocking'. He found that things like platinum, silver and lead were able to hold these free radicals. Midgie figured that if he could get lead oxide spread through the mixture, sooner or later the free radicals would bump into a bit of lead oxide, which forms lead dioxide, as lead has four bonds, but that breaks down to lead, Pb2, and oxygen, O2, but slowed down the reaction.
"In searching for a way to get the lead spread through the mixture, Midgie found a compound called lead tetraethyl which is similar to the combinations in the groups making up petrol. The first good thing about it is because it is like petrol, it is soluble in petrol. The second is that it vaporises like petrol, which means that the lead tetraethyl is dotted around in the mixture. The third thing: it breaks down to lead at upper cylinder temperatures, lead atoms spread around and the ethyls are let go. Then the lead does its job, combining with the free radicals and slowing down the reaction.
"Midgie's research took the octane number from 50 to 65; then research at the refinery introduced crackling reforming and improved the octane number past 89; then, with further developments and money, they got the octane number up to 110 for aviation fuel.
ENTER THE GREENIES
"'Clean up car exhausts' was the cry. By 1975, lead was being reduced in petrol because lead is a poison-that is a general statement; however, to get the fact exact you should say lead is a poison when it is absorbed into the body.
"Now, the fact that lead is a poison if absorbed, does it follow that the lead in our bodies is from the lead in petrol? That was the debate in the early '80s. There were a large number of contradictory reports in the papers, and the National Energy Advisory Committee reported 'no single case of clinical lead poisoning has ever been demonstrated to be due to automotive emissions of airborne lead'.
"There were tests and arguments all over the world. In Frankfurt, the government decided they would cut the lead in petrol from 0.4 to 0.15 grams per litre, about two thirds. Now if the lead was a problem, it should have an effect on the community. If petrol is causing part of the lead in the community and you cut it by two thirds, any scientist knows it must have an effect, otherwise it had nothing to do with it.
"The nett result: 'Since the changes observed are only of the order of statistical scatter (that is, you would never measure anything and get the same thing twice), this indicates that lead from petrol did not contribute to uptake by ingestion through significant deposition on food and utensils as has been suggested. If it had done, greater and continuing decrease in blood levels in the community should have been observed.'
"In other words, they measured nearly a thousand people over a five-year period and there was no change at all despite cutting the lead content in petrol.
"In London we had Professor Lowthur of the University of London pointing out that the lead that comes out of the exhaust has been baked at 2,000-3,000 degrees Centigrade, like a house brick, but so small that you need a microscope to see it. It doesn't get absorbed through the lungs and doesn't even dissolve in the diluted hydrochloric acid of the stomach.
"It appears that the lead in the air is not the source of the lead that is observed in the community.
"Besides, you can measure the lead coming out of the cars and it settles. You measure it as grams per cubic metre at the edge of the road, but if you go back ten feet it is less because it's very heavy dust. Even though it's very small particles it is very heavy."
ENTER THE POLITICIANS
(In 1983 Dr Warren was the scientific adviser to the committee for Energy Resources.)
"The question came up: 'Will we ban lead in petrol?' The real question was will we have ULP?' The real reason for ULP was that people wanted to fit catalytic converters on their cars to get rid of the nitric oxides, carbon monoxide and unburnt petrol that came out, but the lead spoilt the catalytic converters. That was the reason that the rest of the world gave up lead in petrol. The other countries banned it to bring in converters; we banned it because we think it's dangerous.
"So I (Dr Warren) prepared a speech and convinced the Committee-about a dozen people from both parties-that lead didn't need to be banned and that we didn't need lead-free petrol because the evidence wasn't there.
"I prepared a subsequent speech presented to Parliament by the then-State Member for Ballarat. At the same time there was a paper from Dr Bell, the Director of Health of the New South Wales Government.
"Dr Bell asked what was going to be added to the petrol to raise the octane number if the lead was removed: 'If the lead is taken out, you have to add other things to run them in our cars; we put in benzene, toluene, xylene, dimethylbenzene or mesitylene. They're all ring compounds and the dangers are that some of them are declared carcinogens and the others are suspected carcinogens. We're going to cut lead even though there is no proof that it does anything wrong, and we're introducing substances which will ultimately be affecting the cancer rates in our country.'
"The answer was: 'We have converters and they will destroy them', but we all know that converters don't work until they are hot-about the first three miles or so-and every time you fill up, the vapours are coming off.
"Now when the speech was delivered to Parliament, there were only two people listening: myself (Dr Warren), to see that he got it right, and the Member giving the speech. It seems that the prevailing attitude was: 'Don't confuse us with the facts; our mind is made up, the people want it and that is where the votes are.'
"Nobody listened to that speech because it was party policy: both parties said, 'No, we've decided-it doesn't matter what the man says; go and have a drink at the bar and when the bell rings we'll come in and vote'-and that's how it was decided!"
ULP HEALTH RISK
Even at that stage, Dr Warren had found that the lead problem was highly overstated and that the potential hazards from the aromatic octane enhancers-like benzene-were greater than the perceived lead problem.
"In fact, this stuff appears to be so dangerous, potentially lethal, that I urge you not to use it in any car not fitted with a catalytic converter. Don't use it in your mower, chainsaw, whipper-snipper or outboard motor, and don't wash parts in it. If any gets on your skin, wash it off immediately. Avoid the fumes when refuelling and don't allow anyone near the exhaust, particularly when the exhaust system is cold. Remember that catalytic converters don't work until they reach some 400 degrees C."
In Britain, this risk is so clear that the National Society for Clean Air has removed their support for ULP!
Dr Warren's research showed that the lead in blood comes not from breathing airborne lead but from eating and drinking it-that is, principally from soldered food containers, lead-based paints and lead pipes.
In fact research showed that the blood lead levels were higher in country people drinking bore water, such as the New Guinea highlanders and peoples on remote islands, without motor vehicles than in blood samples taken from those living in the heart of Melbourne.
ALTERNATIVE
You will recall in the past I have referred to a device invented by Mr A. Bodycomb. This device would do essentially the same job as a catalytic converter, that is, remove carbon dioxide and unburnt fuel from car exhausts, but it would also remove lead-so there would be no need for ULP!
This device was tested in the early '70s, but those testing it seemed conveniently to forget the test results later, favouring instead the dry converter that we now have.
Mr Bodycomb lives in Melbourne and even now cannot get anyone interested enough to have a look at it.