More Pollution From An “ecological” Law
    By Enrico Dorigo | December 9th 2010 07:30 AM | 17 comments | Print | E-mail | Track Comments
    About Enrico

    I am an Italian student of 19 and I am from Venice. I am intrested in pollution and economical problems in general. I am currently studying Economics...

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    In Europe and worldwide the public attention to environmental protection is growing, together with research of new technologies and new solutions to reduce pollution sources, also in the field of energy and mobility.

    However governments and public authorities often establish laws to improve the environment conditions, promising great results, without taking the trouble to provide and manage their actual effects, which in some cases even become the opposite of those expected.

    The failure of the Italian government deserves to be mentioned as a glaring example, that in accordance with the directives of the European Community, starting from January 1st 2002, it had forbidden the marketing of leaded gasoline, called "super", that is gasoline containing Tetraethyl lead. For nine years they have not been providing any effective action that would promote, with the right mix of penalties and rewards, the quick replacement of all old cars without catalytic converter, in Italy also called “Euro zero” cars, with new cars equipped with catalytic converter, or their conversion to methane CH4 or to LPG (Liquid Propane Gas), supply systems which would allow polluting emissions even lower than those of cars self-catalyzed of first-generation (in Europe called “Euro 1”).

    According to the data I have processed from the statistics made by the Automobile Club of Italy (ACI) on the lists of the Public Motor Vehicle Registry (PRA), in 2001 in Italy were circulating more than 12.2 million “Euro zero” cars, not counting motorcycle and business vehicles: the supply with unleaded gasoline for all these cars, and their prolonged use in the following years caused, as we will see, a very heavy worsening of polluting emissions.

    The gasoline called "super" contained, as main ingredient anti-knock, tetraethyl lead, Pb(C2H5)4, recognized since its discovery by Thomas Midgley in 1921 as the most effective anti-knock between all the compounds then known

    Tetraethyl lead, initially added to gasoline along with Pent carbonyl iron Fe(CO)5 and then to aromatic ammine aniline C6H7N, was used to upgrade the octane number of fuel, increasing with its anti-knock effect the pressure ratio withstood by the air-fuel mixture, to allow a higher supply of power of the engines.

    Tetraethyl lead was recognized as a neurotoxic substance of very high concern, and in 1999 it joined in second place in the list of the Agency for Toxic Substances and Disease Registry of U.S.A.; it showed a great power of polluting of groundwater and of the ecosystem, because is non-degradable in any way, and capable of being accumulated at high speed in living organisms. Therefore leaded gasoline was gradually banned, first in the U.S. in 1986, then in Europe, since 2002, and replaced by the new unleaded gasoline.

    It is well known that unleaded gasoline is certainly not devoid of noxious substances: it is composed, like leaded gasoline, of the traditional mixture of heavy hydrocarbons in open-chain derived from oil, but it contains as anti-knock, in place of tetraethyl lead, a mixture of monocyclic aromatic hydrocarbons in closed chain, including benzene C6H6., methyl tert-butyl ether C5H12O (MTBE) and ethyl tert-butyl ether C6H14O (ETBE) to the maximum extent of 40% allowed in Italy by Law n° 413 of 1997, then reduced to 35% by Legislative Decree n° 66 of 2005.

    Since 1987 the International Agency for Research on Cancer (IARC), in supplement 7, inserts benzene in Group 1, the one of substances proved to be carcinogenic in humans; the International Programme on Chemical Safety - Poisons Information Monograph of 1999 states that an exposure of five to ten minutes at a rate of benzene of 2% in the air (or 20,000 ppm) is sufficient to bring an adult to death. In general, all aromatic hydrocarbons are considered potentially carcinogenic, and also the use of MBTE in gasoline was recently banned in the U.S., especially for its high capacity to pollute groundwater.

    To sum up, to replace tetraethyl lead, which had a powerful anti-knock effect, larger amounts of aromatic hydrocarbons had to be added to unleaded gasoline, and these have increased the intrinsic toxicity; nevertheless these compounds were chosen because they were the best suited to be eliminated with the technologies available at that time of reducing emissions derived from vehicles, or catalytic converters of exhaust gas, also called "catalysts" that were required by law, that couldn't work with the presence of lead.

    The catalyst, as I have learned from a chemistry research done for my school, is needed to break down the molecules of pollution contained in the unburned gases produced from the combustion, never fully complete, from the air-fuel mixture in the combustion chambers of the cylinders of the engine; in fact the perfect combustion of a hydrocarbon would produce only heat, carbon dioxide CO2 and water H2O; instead, the incomplete reaction with oxygen O2 in the combustion produces carbon monoxide CO and unburned hydrocarbons HC. In addition, in high temperatures and pressures oxygen can also burn nitrogen N2 of the air shaping small amounts of nitrogen oxides NOx.

    The catalyst is used to complete the oxidation of unburned hydrocarbons HC and of carbon monoxide CO, making it capable to accelerate the chemical reaction with oxygen O2 through the precious metal catalysts, palladium Pd and platinum Pt, to convert them into carbon dioxide CO2, water H2O and heat , as in the perfect combustion.

    The modern catalysts are called trivalent, because in addition to HC and CO, they are able to break down also the third pollutant, nitrogen oxides NOx: made by adding before the oxidation catalyst, a catalyst reducing agent, which through the rhodium Rh at temperatures between 300 ° C and 900 ° C, can reduce the unstable molecule of nitrogen oxide NO in nitrogen N2 and oxygen O2. The system is completed by so-called Lambda sensors, which detect the level of oxygen in the exhaust gases, and allow the electronic control unit of the car to maintain regular the gear between stoichiometric air and fuel introduced into combustion

    Therefore it should have been clear that if the engine of a “Euro zero” car, without catalyst and lambda sensor, is fed with unleaded petrol, then all the toxic and carcinogenic substances contained into unburned gas of unleaded petrol, with no dampening, will be released into the atmosphere from its muffler.

    Furthermore, these emissions are much higher in quantity than those resulting from the combustion of the old petrol with Tetraethyl lead, both because of the lower amount of this substance in the old gasoline due to its superior anti-knock effectiveness, and the worse working of the older engines designed for fuel with characteristics very different from those of the new unleaded petrol.

    Only the City Council of Rome had the courage to impose, before the government issued the country-wide ban of marketing of leaded gasoline, a resolution (number 790 of 2001) which prohibited the traffic of all cars without catalyst for 24 hours a day and 365 days a year, at least inside the ring rail of the city, an area corresponding to one fifth of the inhabited territory of the city.

    The Italian governments instead have never even tried to study an effective program to limit the traffic of “Euro zero” cars, and have stuck in the past nine years with the allocating of some state funding of incentives to the scrapping of old cars in case of purchase of new vehicles: these incentives were financed with sums from 1000 to 1500 euro (1400 to 2000 US dollars) for each car, an amount which would have been enough to impose at least the installation of an LPG or methane supply system to “Euro zero” cars for those who did not have the money to buy a new one!

    Therefore the inaction of Italian governments has allowed, in reality, many of the cars without catalyst to remain in circulation without replacement or conversion by their owners, who were mostly the less well-off Italian citizens, more and more numerous for the economic crisis in recent years, or immigrants flocking to Italy from less developed countries, who bought them at a low price, and to whom “Euro zero” cars are the only private transport at an affordable price.

    To demonstrate this, the lists of registration and cancellation of the Public Motor Vehicle Registry (processing of ACI) show how the decline in the number of “Euro zero” cars trafficking in Italy has been very slow: 9.5 million in 2003, 7.5 million in 2004, 6.6 million in 2005, 5.2 million in 2006, 4.6 million in 2007, 4.2 million in 2008, 3.1 million in 2009!

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    I did not find specific publications that have quantified the actual environmental damage caused in Italy by the deleterious allowance of circulation, in the past nine years, of cars without catalytic converter. However I have found an important data source "Estimated emissions from road transport 2000 – 2005” compiled for the Italian national inventory of emissions based on the method COPERT III (Computer Programme to calculate Emissions from Road Transport), and reported to international agencies by Riccardo De Lauretis (National Reference Center of the European Environmental Agency for the inventory of emissions); these data are published on the website of the Italian state institute ISPRA (National Institute for Environmental Protection and Research).

    Using data ISPRA, I produced a summary comparison of the annual emissions of major pollutants of all gasoline passenger cars without catalytic converters (European categories "PRE ECE", "ECE 15/00-01"; "ECE 15/02"; "CE 15/03", "ECE 15/04), with the annual list of similar emissions from all gasoline passenger cars with catalytic converter (categories European" Euro I - 91/441/EEC "," Euro II - 94/12 / CE ";" Euro III - 98/69/EC Stage 2000 "," Euro IV - 98/69/EC Stage 2005 "Euro V post 2005") within the first 4 years after the abolition of leaded gasoline, i.e. from 2002 to 2005 (I have considered only the passenger cars for private transportation, no motorcycles or commercial vehicles).

    In 2002 were in circulation 10.7 million old gasoline passenger cars without catalytic converter, hereafter also named "NO CAT" cars, and 15 million new gasoline passenger cars with catalytic converter, hereafter also named "CAT" cars; the CAT cars have covered 179,402 billions of kilometres, the NO CAT cars only 55,774 billions of kilometres: therefore the CAT cars have travelled, all together, a more than three times longer distance than NO CAT cars, although they gave off a much lower amount of pollutants, especially those characteristic substances of unleaded gasoline, as aromatic hydrocarbons, which are more capable of being oxidized in the catalysts, and as nitrogen oxides NOx, the catalysts are able to reduce nitrogen and oxygen.

    Looking at the first year of ban of leaded gasoline, in 2002 NO CAT cars gave off 4,291 tons of benzene C6H6, 107,981 tons of VOC (Volatle Organic Compounds), 114,332 tons of nitrogen oxides NOx, while CAT catalytic cars have given off 1,693 tons of benzene, 33,438 tons of VOC, 52,310 tons of nitrogen oxides NOx. This difference of pollutant emissions is also evident in the subsequent years 2003, 2004, 2005 of the ISPRA investigation.


    The largest difference in emissions per kilometre run by cars without catalytic converter compared to those with the catalyst can be calculated from the data above; furthermore, looking at its constancy in time, it is possible to understand how this absolutely avoidable pollution has been continuing for even four years after the 2001 - 2005 period I have taken into consideration.

    By multiplying the emissions per kilometre of CAT cars indicated by ISPRA, with kilometres run by NO CAT cars in the four years 2002 - 2005, and subtracting the low volume of pollutants obtained from the total volume of pollutant emissions of NO CAT cars, we can highlight the volume of pollutants given off by NO CAT cars, that I call "avoidable pollution", because those could be saved if their kilometres had been run by CAT cars: for example in 2002, 3,765 tons of benzene, 97,586 tons of VOC, 98,070 tons of nitrogen oxides NOx would have been saved.

    The same calculation stretched in subsequent years will show impressive data about the amounts of “avoidable pollutants” that could have been saved: 11,641 tons of benzene, 307,214 tons of VOC, 324,883 tons of nitrogen oxides NOx (see “total” column of Table 2).

    By extrapolating the data mentioned above on the number of “Euro zero” cars circulating in Italy in the four-year period 2006 – 2009 we see that, having allowed the circulation of overall almost 50% of the “Euro zero” cars present in the four years 2002 - 2005, we can estimate that these cars have given off a similar percentage of the "avoidable pollutants" just discussed, and therefore it can be estimated with sufficient accuracy the total amount of pollutants that could have been saved in the past nine years since the abolition of leaded gasoline: more or less 17,000 ton. of benzene, 450,000 ton.of VOC, 480,000 ton. of nitrogen oxides!

    December 9th, 2010

    Enrico Dorigo


    Good article.   Italy is not alone in its use of political 'placebo' - California has high emissions standards, it thinks, yet cars owned by the poorest people and emitting the most pollutants are exempt, while slightly poor and middle class people have to pay more for cars, meaning they drive their older ones longer.

    We also advocated methyl tertiary butyl ether (MTBE) without merit and to disastrous effect in the groundwater.    But they banned leaded gas and MTBE was the only way to meet the oxygenate requirements set by the United States Congress in Clean Air Act amendments.   It proves again that mandating punitive actions without a positive replacement is a bad idea.
    Much of this is news to me.  But aniline added to petrol?  That sounds really nasty.  When was that practice stopped?

    This got me reading up on petrol additives (my knowledge thereof is very out of date.)  I found this:

    Methylcyclopentadienyl manganese tricarbonyl (MMT or MCMT).  Is this used in Europe?
    Robert H. Olley / Quondam Physics Department / University of Reading / England
    I'm not so expert in this subject, but about the aniline it was used definetly, I don't know if also in Europe, in Italy to discern the "red" petrol from the "green".

    I have never heard about MMT or MCMT.
    I’ve not heard of “red” or “green” petrol.   What do these terms mean, and is this distinction still made?

    I found very few references to this, but here’s a 2008 one from China:

    Simple Synthesis of N-Methyl Aniline over Modified Kaolin for Octane Number Improvement

    and this from the UK, 1994:

    Petrol octane booster and methaemoglobinaemia

    Keywords: aniline, methaemoglobinaemia, petrol octane booster

    Robert H. Olley / Quondam Physics Department / University of Reading / England
    Firstly I am sorry if I start answering you so late but today I had a lot of work to do. Despite this I am delighted to recive so many comments and compliments, thankyou to everbody.

    This distinction is an Italian "production", in fact the surname "green" and "red" are used because the biggest part of people don't know what is the leaded and the unleaded petrol. To make it more easy to understand and to avoid problems, unleaded petrol was named "green" and leaded petrol "red", also beacuse the adjective "green" in Italy is a synonymous of "ecological". It was named "green" to indicate that, beacuse it is without lead, it is more ecological.
    Great article Enrico.

    Great! My only suggestion would be to snip a few run-on sentences shorter and do away with some (or all) of the semicolons. Very minor issues overall though. I am a little less than double your age and looking back at some of my writing from when I was as old as yourself is more than slightly embarrassing! I would estimate, roughly, that your intelligence level, scientific literacy, and writing proficiency easily exceed at least 95% of that of similarly aged citizens in my country, the US.

    Best of luck in your studies, and here's to hoping that your uncle can manage to lure you over to the Dark Side of high energy particle physics. (There's still time Tommaso!!)

    I agree, I was barely writing D&D modules at his age much less anything of this quality.
    Thankyou very much, especially for the advices, this is my first article and so I have zero experience on write them. Advices are very useful for me to write better the future articles.

    I can see you've spent a lot of time on this, however, the problems are more complex even than you describe

    Here in UK, there have been schemes introduced to encourage new for old cars, and changes to the  Car Tax Law especially for '4WD People carriers' [known as 'townie tractors'] and entry into the Low Emissions Zone in London

    Part of the problem is the political 'jumping on the bandwagon' without fully understanding the problems

    It is not just that the cars which we know about give off more pollution, the expected results of catalytic converters has not been fully thought through.
    1) They are affected by poor/inefficient working at low temperatures
    2) They do not have a good recycling scheme in place for the precious metals, nor for the high concentrates of pollutants contained in the 'converters' which clog and need replacing approximately every 3/4 years
    3) The computers used in many vehicles break down and autoswitch to 'get you home mode' and because of horrendous repair charges and insufficient training/knowledge by garage staff/mechanics/fitters - drivers continue using vehicles in this state producing abnormally high pollution until the next vehicle pollution test
    4) Lambda sensors from the wrong vehicles/or of the wrong type are being fitted, which again cause abnormal levels of pollution, sometimes when complete exhaust systems are changed
    5) Some vehicles have EGR valves in the inlet manifolds, designed to recirculate exhaust unburnt gases back through the engines causes manifold fowling and sooting of sensors, also causing excess pollution
    6) many after market tune up kits get fitted increasing overfuelling in an attempt to increase horsepower for the speedjunkies [I know, I was one]
    7) Also available as aftermarket kits are unregulated OxyHydrogen/HHO kits, which allow unmetered oxygen and hydrogen from an electrolysis unit, advertised variously as boosters/pollution preventers/MPG increasers/tune-ups etc but few have proper metering or input to any computerised fuel metering fitted to the vehicles - with varying results on pollution, though generally more favourable than unfavourable, due to a better burn of fuel due to increased oxygen
    There also additives [various chemical compositions] ....
    (Quote: The various lead replacement additives currently on the market contain as their base chemical constituent one of the four following: - A) Potassium. B) Phosphorous. C) Manganese. D) Sodium. However one point of view was shared by all associated bodies.
    Under no circumstances mix or alternate additives  [you can guess the outcome...different garages stock different additives)
    ...... still being sold for cars which weren't designed to run without leaded petrol, designed to prevent burning of the valve seats in the cylinder head

    There is, to the best of my knowledge no monitoring of these known problems!
    ....and then there are the hybrids, with their demand for rare earth elements, calor gas conversions, which have similar metering and catalytic converter problems and 'common rail' diesels, thought to be vast improvements, but which in reality produce smaller droplets of pollution than mechanical pump diesels, but overall very similar total pollutant levels....
    Our 'Transport for London' have refused to amend data for diesels, despite many earlier engined vehicles with Oxyhydrogen proving to be 100 times lower than required/allowed vehicles on the current test equipment, banning them from entering London
    I have a friend who has a 25 year old 6 ton Camper with a Perkins 4ltr diesel engine which has less than 60,000 mls on the clock, still bettering what many 'allowed vehicles' regularly spew out, yet he has moved rather than part with his Van

    Thanks for your comment thorough and interesting.
    the little I know on the subject, I understand that all the factors you mentioned are important on extablishing cars' level of pollution.
    I also do not think that the catalysts solve the problem of pollution from cars traffic, but I just wanted to point out that in Italy much of the pollution that could have been avoided, have been caused by the banal mistake of leaving in circulation millions of old uncatalyzed cars that are powered by unleaded petrol. However I think that point 2) of your comment highlights one of the most important factors that governments should correct: also in Italy there isn't a normative and a control system, which could require motorists, repair shops and automotive replacement shops, to change the catalyst of the exhaust gas when the car reaches its end of life, after 3-4 years of normal use, with a new catalyst, which costs more than € 1000: today, unfortunately, is a common bad practice to replace the catalysts at the end of life with the old mufflers without catalytic converter, which cost a little more than € 100: there are so many people that, with the possibility of save money, ask for and pbtain to not install the new catalyst, and replace it with just an addictional piece of the muffler.As a conseguence even if the not catalyzed cars have been gradually disappearing, their heavy polluting effect is constantly helped by the arrival of new cars produced with the catalyst but not turned into self-catalyzed cars!
    To sum up, to replace tetraethyl lead, which had a powerful anti-knock effect, larger amounts of aromatic hydrocarbons had to be added to unleaded gasoline, and these have increased the intrinsic toxicity

    I'm not sure that this is strictly true from an environmental perspective. I agree it may be quite nasty to work directly with the unleaded gasoline, compared to leaded gasoline. However, you note that tetraethyl lead does not degrade. Therefore it continued to build up in the environment as long as it was in use. Based on the names of the new additives, it seems like there is nothing special about these molecules that would prevent degradation. Have you looked into the persistence of these chemicals at all? They may be "intrinsically" more toxic as you say, but their "effective" toxicity may differ for this reason.

    Sheer amounts of toxic chemicals do not directly define "intrinsic toxicity" either. Some toxins are effective at smaller doses than others. To make a truly convincing toxicological point, it's important to compare the effectiveness of similar doses of tetraethyl lead to the other additives in bringing about the toxic effects (neurotoxicity, cancer, etc.). Except in the case of a benzene spill, for example, it seems highly unlikely that one would ever see 2% benzene in the atmosphere -- so simply claiming that benzene can kill is not a sufficient analysis when children have exhibited toxic effects of lead from eating some paint chips.

    Still, very impressive work! Any plans to become an environmental chemist?


    Thanks for the encouragement.

    As for the "biggest intrinsic toxicity" of benzene among tetraethyl lead, it is true that I used a term perhaps fulsome: in fact I agree that the parameter of persistence over time, which was proved to be very high for tetraethyl lead, could make this substance more dangerous to the environment of benzene and aromatic amines in general, and it is also true that the effect of a 2% concentration in air is pure speculation, because it is not concretly reachable in our cities, but I have mentioned it only as an extreme example of the toxic ability of the molecule towards human health, as I do not have exhaustive knowledge about the toxicology.

    I like the chemistry, and also the issues about environmental protection, but I don’t still know what branch of studies is better for me.

    I happily join the praising crowd here, after seeing that Enrico's first piece has indeed raised interest, and observing that his answers to this rather technical thread have been consistently up to the mark. Good job Enrico. I think you can take on any kind of scientific studies you like. The trick is to find something you do like at all levels: from the outset, the technical parts, the goals, and the job offers it will finally lend you. It is not enough to choose a field of science because you are good at it at high-school level. So this requires meditation.

    I was very impressed by reading Edward Witten's statements somewhere, the other week, about his difficult quest for a discipline he liked. Ed, for those of you who do not know him, is one of the brightest thinkers in the world, a theoretical physicist whose articles have more citations than anybody else. But before he got to understand he was good at theoretical physics, he tried history, economy, maths. And he said that the problem is not to have or not have talent - everybody has some hidden talent. The real problem is to find out what this talent is, and find the best way to fully exploit it.

    Wise words from you, Tommaso
    The real problem is to find out what this talent is, and find the best way to fully exploit it.
    ......and from Ed Witten

    hi enrico

    nice article, i can add, that in Denmark there has been added Barium to the gasolin fuel and later on Barium was added to diesel as well.
    I have experienced that it is some how highly secret!? I asked a "worker" on a gasolin station, he was there with a special vichle to test the gasolin and diesel from the pumps.
    I asked him about the additives, and he imidiately said that he could not talk about that.
    I asked about this dude in the government department for environmental issues they did not know of any test like that.
    Strontium was used as an additive as well in city busses in the city of Odense, the initial test was made by Henrik Friis (former DTI = Danish Technical Institute now he works for MAN Diesel).

    i have found many more additives of metallic origin, especially now that ultra-low-sulfur diesel is out. sulfur is/was what i understand the lubricating substance in diesel, it as well has to be replaced by ......
    most lubricating additives are metal in origin, from eg. the manufacture Lubrizol.

    and the science for the catalytic converters, might not be all sound and safe.

    i have also asked the DMU (Danish Invironmental "Investigation") on why they never look at the fuel ingreediences/additives before trying to meassure the exaust, with eg. the Borch method or some other invalid measurement tecnics. If you meassure the blackness of a filter, when you do not know that there is Barium (as permanent white) in the fuel - the results will be very wrong.

    kind regards
    currently living in Denmark

    You wrote very interesting things. Demark is an advanced country in the field of environmental protection, therefore I am really smitten for what you said about additives. I have the same opinion about it, strict controls should be done on the effects that some fuel additives as Strontium and Barium have to the health. The problem is that the emissions of CO and of NOx are controlled, not as all the other dangerous substances. Governments should require fuel producers to declare the components of diesel and benzene, and the overcoming of special severe tests before authorizing the marketing.