LEAD Action News
LEAD Action News vol 8 no 2, 2001, ISSN 1324-6011
Incorporating Lead Aware Times ( ISSN 1440-4966) and Lead Advisory Service News ( ISSN 1440-0561)
The Journal of The LEAD (Lead Education and Abatement Design) Group Inc.

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Fully Referenced Expanded Version of
"New strategies needed to cut lead pollution",
Guest Article, Science and Technology Column, Canberra Times
Thursday 25th January 2001

Lead - From The Petrol Bowser To Blood And Bone - part 8

by Elizabeth O'Brien, National Coordinator of The LEAD Group and
Mariann Lloyd-Smith, Coordinator of the National Toxics Network

ct.jpg (63756 bytes)

A RESPONSE TO: "Lead may be dead but we've been had"

PDF version of this file: New strategies needed to cut lead pollution

ENDNOTES - Leaded petrol phase-out helped reduce benzene emissions

In the last paragraph of the Canberra Times article, the issue of benzene in vehicle emissions was mentioned:- "many of our post-1986 cars have inefficient catalytic converters, causing our unleaded emissions to contain high levels of benzene". A fuller account of the benzene issue is called for, but briefly no matter how "high" the levels of benzene are currently, the levels are lower now than during the reign of leaded petrol:

Lead in petrol prevents the use of catalytic converters as the lead poisons the catalytic converter. Catalytic converters reduce more than just benzene emissions.

In 1996 the CSIRO reported that over the whole fleet (including poorly performing cars) catalytic converters reduce aromatic emissions of benzene on average by 70 per cent

Valerie M Thomas (1995) has reported that:-

"Octel, the manufacturer of TEL [tetra ethyl lead - the lead additive in leaded petrol], has made the benzene emissions of unleaded gasoline the focus of its international effort to market leaded gasoline. According to John Little, Managing Director of Octel, "We have launched a worldwide effort to promote the dangers of using unleaded gasoline, particularly in cars that are not equipped with catalytic converters…For the past five years we have been visiting developing countries to promote the use of leaded gasoline and to warn against the use of unleaded in non-catalyzed cars". This corporation has actively campaigned in the United Kingdom, Israel, Egypt, Hong Kong, Italy, the Philippines, New Zealand, Australia, and elsewhere. Octel claims that use of unleaded gasoline in cars without catalytic converters may increase exposure to benzene. Based on this claim, Octel argues that only cars with catalytic converters should use unleaded gasoline."

The levels of benzene in unleaded and leaded petrol in Australia are essentially the same. Leaded petrol is basically unleaded petrol plus lead (NRMA, 1996). Yet the 1996 CSIRO report showed that using Australian unleaded petrol compared to using leaded petrol in pre-1986 cars even without catalytic converters reduced the volume of emissions of benzene on average by 30 per cent. The reduction of benzene and other aromatic emissions from low octane unleaded fuel may be the result of the more efficient combustion of petrol in the absence of lead.

So in stark contrast to the policy of Octel to promote the dangers of unleaded petrol in regard to benzene emissions in Australia (Gidlow, 1995; Associated Octel, 1995a,b,c&d), Australia has seen an excellent reduction in the total estimated benzene emissions (AIP, 1994) from our car fleet over the period of the phase-down of leaded petrol - both due to more drivers using unleaded petrol in cars without catalytic converters and the fact that all new cars since 1986 have had catalytic converters.

Up to 20% of benzene emissions from vehicles are due to fuel evaporation (AIP, 1995) and since these emissions don't pass through the catalytic converter, evaporative emissions are the same regardless of the efficiency or presence of a catalytic converter (Thomas, 1995)

A World Bank report from 1998 states that "the magnitude of health impacts caused by benzene exposure should be compared to those of lead exposures. [The US EPA] estimated that 47 cases of deaths from leukemia could be attributed to the exposure from gasoline. For comparison, the annual number of deaths avoided by the reduction of lead in gasoline (only one of the positive impacts of reducing lead), has been estimated between 4,000 and 5,000." (Lovei, 1998)

There are far greater concerns about benzene emissions from non-vehicle sources. The exposure of smokers to benzene, for example, exceeds the exposure of non-smokers nearly 10 times (Lovei, 1998)

PDF version of this file: New strategies needed to cut lead pollution

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