[sustran] (no title)

[Roger Higman]

Friends

Obet Verzola writes:

> The government is pushing for the use of unleaded gasoline, because
> lead causes brain-damage. I've met a chemical engineer from an oil
> company who insists that in unleaded gas, the lead has been replaced
> with benzene, and that benzene is highly carcinogenic. He says that
> benzene emissions can be reduced by catalytic converters, but most
> cars in the Philippines don't have these converters because they add
> about $100 to the price of a car.
 
> I would appreciate the facts about this issue, and if there are other
> things we should know about potential dangers from unleaded gas


Lead certainly damages children's brain development. In the UK there has 
been a marked drop in average blood-lead concentrations following the 
reduction in lead content of petrol and an increase in the use of 
unleaded.

Benzene is a proven carcinogen. It is frequently added to unleaded 
petrol as an "octane booster" to make the petrol burn properly. 
Previously lead compounds served this function. However, the consensus 
in the UK is that unleaded is a less danagerous fuel than leaded even 
for a car without a catalyst. You may have problems, however, if your 
oil industry tries to market petrol with a very high benzene or aromatic 
content (ie: I think approaching 5% benzene and/or more than 45% 
aromatics). This is done because it gives the cars more power but is 
completely unnecessary.

Benzene is not the only "octane booster" that can be added to petrol. 
Compounds like Methyl Tertiary Butyl Ether (MTBE) and Ethyl Tertiary 
Butyl Ether (ETBE) are added to reformulated gasoline in the USA and 
Europe. These are probably carcinogenic also, but to a much lesser 
extent than benzene. I believe is also possible to add alcohols as well.

New European legislation will limit benzene and aromatic content (and 
ban leaded fuel). This will probably lead to greater use of MTBE and 
other "oxygenates" like it.

At the end of the day, there is no such thing as a completely clean 
petrochemical fuel. Even getting rid of petrol altogether and burning 
alcohols or natural gas will lead to toxic emissions. And the 
electricity for electric cars has to be generated somehow (and often in 
polluting ways).

You should therefore try to minimise the health-threatening emissions. 
Removing lead is an extremely important step in that direction, even if 
it used by cars without catalysts. 


Roger Higman                                    "A thorn in the side of 
Senior Campaigner (Atmosphere and Transport)         the motor industry"
Friends of the Earth (E,W+NI),  	        	   Car Magazine
26-28 Underwood Street,
London, N1 7JQ
                                                       
Tel      + 44 171 566 1661                       Fax   + 44 171 490 0881
E-mail   rogerh at foe.co.uk                        http://www.foe.co.uk