Nexus - 0226 - New Times Magazine-pages

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AIR POLLUTION Dr Michael Dawson explains that when the oil companies removed pi from US gasoline in the 1980s, the H—23 J increased aromatic con- tent had two deleterious effects: "Firstly, air pollution became worse because aromatic compounds are very photochemi- cally active. Secondly, tailpipe emissions of the carcinogen benzene increased."* Table 1: Premium Unleaded Gasolines—An International Comparison (N. G. Child/Dr M. Dawson, 30/3/95) SATURATES | OLEFINS | AROMATICS OXYGENATE BENZENE = mia (%v/v) (%v/v) (%v/v) L584 | SAMPLE DATE| GRADE COUNTRY USA GREAT BRITAIN GREAT BRITAIN SINGAPORE AUSTRALIA [97.9 Set/ Dee 154 | Premium rses| see 78 [ sen [ao fa Ex ; Premium NETHERLANDS Premium Premium | 98.7 GERMANY Premium . NORDIC [Premium | 96.0 SPAIN January 1993_[ Premium] 96.1 | 47.6 MID-EUROFE [January 1993 [Premum[ 95.4] 55.4 | 69 | 377 | 44] 18 _| Dr Michael Dawson says that "Eventually, the lead content in BENZENE IN THE ATMOSPHERE leaded petrol will be reduced to almost nil" in Australia, "and we The carcinogen benzene is an inexpensive substitute for lead. will have cars not fitted with catalytic converters spewing out tons As an example, in Germany in 1993, 32 million tons of fuel were more air toxics e@h year than is currently the case."* burnt. Around 10 million tons of aromatics were in this fuel—and The third group of alternative octane-raising substances men- _at least three-quarters-of-a-million tons would have been benzene. tioned above are the oxygenates. A major by-product of their _ A significant amount of this fuel finds its way into the atmosphere combustion is acid aldehyde—the first substance the body pro- _as benzene.’ duces in the alcohol-detoxifying process.“ So it seems that the In 1991 in Germany, about 100,000 tons of fuel escaped during oxygenates are less toxic than benzene and 1,3-butadiene. transport from refinery to filling station; 45,000 tons escaped Another advantage of oxygenates is that, because they contain while gasoline was being pumped into gas tanks, and another oxygen molecules, they cause the fuel to burn more efficiently— 33,000 tons escaped from car motors.’ and thus lowering the levels of all pollutants from car emissions.* Dr Michael Dawson has taken benzene readings in Sydney over Oil companies in Australia don't use these oxygenates because an entire month in summer and an entire month in winter. The they are not by-products of petroleum production and would have —_ measurements revealed average benzene levels of 4.1 parts per bil- to be purchased from other chemical companies, thus making lion in summer, and 7.6 p.p.b. in winter. Peak concentrations them more expensive." reached between 12 and 25 p.p.b. respectively. These readings The US EPA mandated that from Ist January this year, a'"refor- were taken at the same place in the city where carbon monoxide mulated gasoline" is to be sold in approximately 25% of the USA.’ _levels are monitored by the EPA.** A limit of 1% of benzene (10% of total aromatic content) is set for Britain has recently adopted a maximum of 5 p.p.b. of benzene this fuel. EPA sources predict that market share for reformulated _ and has a national target to decrease levels below | p.p.b. gasoline will eventually be 70%.' Dr Michael Dawson says, "Australia has no safe standard for The oxygenate MTBE is one of the substances of concern, men- _ benzene, and its environmental authorities do not carry out regular __ tioned in the article extract from Dr Hans Nieper which follows on —_ monitoring."® page 29. (Note: Australia is the only country listed in the tables The Victorian EPA conducted a study in 1992-93 which found whose petrol contains no MTBE.) benzene levels in Melbourne's inner suburbs of up to 6 p.p.b. This Taking this into consideration, ethanol and methanol may be the —_ agency sets a preferred limit equal to about 30 p.p.b. They quote safest additives—or should catalytic converters be phased out of studies which show that over 75% of benzene in the air of indus- use? Definitely, many more studies have to done on the exact __trialised cities comes from vehicle emissions.® effects of these chemicals. Tests of benzene levels in Baden-Wiirttemberg, Germany, mea- " . . sured statewide aver- Table 2: Regular Unleaded Gasolines—An International Comparison _(N. G. Child/Dr M. Dawson, 30/3/95) age values of between COUNTRY | SAMPLE DATE| GRADE | RON | SATURATES]| OLEFINS ou 2 BENZENE] ©,294 46 micrograms of benzene per cubic (%v/v) (%v/v) (%v/v) . t ; j 24.4 4.1 (MTBE) i rere arate 4 USA Winter 93/94 4.5 (MTBE) mica eeutenll GREAT BRITAIN a monthly peak values of SINGAPORE up to 62 micrograms AUSTRALIA ITALY Oct/Dec 1994 =a 12.7 27.7 0.0(MTBE) | 2.0 | NETHERLANDS —_ — FRANCE en Ee a [GERMANY _| ee 1993 tee 7 } 8 6 _— 0 1.3 (MTBE) J MI-EUROPE rs es (approx. 21 p.p.b.). The Swabian Environment Minister, Harold Schafer com- mented that the levels were "Frightening, ...indeed, dramatically high."” JUNE - JULY 1995 26 ¢ NEXUS