LEAD Action News
2 no 4
Benzene -Scare Campaign Tackled Head-on
A scare campaign over the last couple of years has attempted to convince the public and legislators that reducing the amount of lead in petrol will result in increased levels of benzene in petrol because benzene is the cheapest alternative octane enhancer, and that this has already happened in Australia The benzene content of leaded petrol may have increased in other countries as the lead has been reduced but to The LEAD Group's certain knowledge, the benzene content of leaded petrol in Australia has not increased as lead has been decreased, in the period 1991, when The LEAD Group was set up, to the end of 1994 (see graph below.
Benzene, which is a natural component of crude oil, is permitted in Australian petrol up to a maximum of 5 per cent. The normal range for Australian petrol is between 2.5 and 3%. The rumour being put about is that refineries have taken the option of raising the benzene content up to the permissible 5%.
This has not happened between 1991 and 1993 as the graph shows. To ensure that it does not happen in the future, The LEAD Group will be calling for a legislative limit on permissible benzene, at certainly no higher than 3%.
But wait: as Demtel says, there's more. 'Re lead additive industry is a hydra-headed monster of great vigour. Another of its rumours is that unleaded petrol contains more benzene than leaded. Not true. They are about the same - that is, between 2.5 and 3%. To make leaded petrol, the refiners (other than Shell) tell us that they simply add lead to low-octane unleaded petrol.
The benzene content of unleaded petrol has been increased in certain countries, such as Britain, because of - in Britain's case - a commitment to high-octane unleaded petrol. In Britain, when a car switches from using leaded petrol to using unleaded there is only high-octane high-benzene unleaded available. In Australia, drivers of pre-1986 cars have a choice between low-octane unloaded (now over 50% of petrol sales) and high- octane unleaded (less than 1% of petrol sales) which virtually no-one buys because of the outrageous price differential (7-15 cents per litre).
Benzene in Australian petrol has been going down since 1991, together with the reduction in lead - a possible reflection of the refining industry's concern with the supposed causal link between benzene in motor vehicle emissions and childhood leukaemia. The accepted link between benzene and cancer occurs at occupational exposures to benzene around 5000 times the concentration found in motor vehicle emissions.
A smoker, or a child living with a smoker, will get most of their exposure to benzene from the cigarette smoke. If producers of tetra alkyl lead (petrol additive) were serious about reducing benzene exposure they would join the anti-smoking lobby, as The LEAD Group has done.
The lead industry has attacked Professor Herbert Needleman's 1979 study as to the effects of low-level lead exposure. Professor Needleman's findings have been confirmed and the attacks laid to rest, yet the lead additive industry continues to refer to the research as though it were in doubt.).
Other research increasingly implicates particulates in being a major cause of deaths and respiratory disease linked to motor vehicle emissions. Lead is a significant component of particulates in our cities. See p 4 of this LEAD Action News.
One thing the lead additive manufacturers don't ever mention is that the lead scavengers which must be added to leaded petrol in order to scavenge the lead from the engine, are also linked with cancer, and that the concentration of dioxin (a known carcinogen) is higher in leaded petrol motor vehicle emissions than unleaded emissions as a result of the addition of these lead scavengers. (See Dr Winder's article this issue)
Another claim is that when the amount of lead in petrol is reduced, there is no difference in people's blood lead levels. Not true. US National Health and Nutrition Examination Surveys (NHANES) found a decline in blood lead levels closely correlated to a decline in lead in petrol. See the abstract of the latest NHANES results in this issue of LEAD Action News. And research from Italy found that lead from petrol contributed around 30% of people's lead in blood. Children living near busy roads have higher tooth lead levels according to Danish research (see p 6).
Of course we acknowledge that there are other sources of lead besides petrol. Refer to the Total Environment Centre's lead fact sheet (phone TEC on (02) 9247.4714), and refer to the letter in this LEAD Action News.
By plain truth is that there's over 1000 toxins in petrol - leaded or unleaded. The only answer is to use less of it! That's why we're publishing extracts from the Total Environment Centre's policy on car use reduction
We haven't killed the monster - it's in the nature of a Hydra (a creature in Greek Mythology) - that they grow new heads as soon as the old ones are cut off. But we hope we might have slowed it down a bit! (We'll cut off a few more heads in the next issue of LEAD Action News.)
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Updated 13 November 2012