Lead, gasoline additives

Muller MD, H-R Buser (1986) Halogenated aromatic compounds in automotive emissions from leaded gasoline additives. Environ Sci Technol 20 1151-1157. 

The vast majority of measurements of organolead compounds in the environment do not constitute evidence for biomethylation of lead. Most environmental organic lead comes from incomplete combustion or spillage of methyl- or ethyl-lead gasoline additives (viz tetraalkylleads or TALs). A literature search will produce several hundred TAL or ionic alkyllead results, but few of them are evidence for methylation in or by the environment. 

Illnesses and 15 deaths were recorded at Ethyl Corporation among workers developing lead gasoline additives. 

So many industrial and commercial uses have been found for Pb that it is difficult to list them all. The main uses of Pb which are most relevant to environmental contamination and human exposure are lead-based indoor paints, lead water pipes, lead solder in cans for storing food, and leaded gasoline additives these have either since been banned or are in the process of being banned. Action is also being taken with respect to lead glazes on pottery and ceramics, lead in... 

Isomeri2ation of straight-chain hydrocarbons is of particular importance for lead-free gasoline. Addition of high octane aromatic hydrocarbons or olefins is questionable based on environmental considerations (77). An efficient octane enhancing additive is methyl tert-huty ether (MTBE). 

The future use of lead may be decided by the resolution of an environmental paradox. Some markets for lead are being phased out because of environmental concerns, eg, the use of tetraethyllead as a gasoline additive. However, a 1990 State of California law and similar laws in nine eastern U.S. states require that 2% of new cars meet 2ero-emission standards in 1998. By 2003 this requirement rises to 10% of new vehicles. Zero emission vehicles are generally accepted to mean electric, ie, battery powered cars, and there is considerable research effort to bring suitable electric vehicles to market by 1998. 

Total consumption of lead in the United States in 1993 reached 1,318,800 t. Of this, 766,000 t (58%) is allocated to battery use suppHed as either a mixed oxide or as metal. Approximately 95% of batteries are recycled and the lead recovered. In 1993, 908,000 t of lead came from secondary smelters and refiners compared to 350,000 t originating in primary mines and smelters (39). Approximately 51,000 t of lead was consumed in U.S. production of all oxides and chemicals appHcable to all industries other than batteries. Estimates include 8000 t for plastics, 6000 t for gasoline additives, 2000 t for mbber, and 30,000 t for ceramics, glass, and electronics. Lead is not used to any extent in dispersive appHcations such as coatings. 

Sodium amalgam is employed ia the manufacture of sodium hydroxide sodium—potassium alloy, NaK, is used ia heat-transfer appHcations and sodium—lead alloy is used ia the manufacture of tetraethyllead and tetramethyUead, and methylcyclopentadienylmanganesetricarbonyl, a gasoline additive growing ia importance for improving refining efficiency and octane contribution. 

Don t use leaded gasoline to rinse bearings. The chemical additives are harmful to your health. 

Some elements come in and out of fashion, so to speak. Sixty years ago, elemental silicon was a chemical curiosity. Today, ultrapure silicon has become the basis for the multibillion-dollar semiconductor industry. Lead, on the other hand, is an element moving in the other direction. A generation ago it was widely used to make paint pigments, plumbing connections, and gasoline additives. Today, because of the toxicity of lead compounds, all of these applications have been banned in the United States. 

The ratio of anthropogenic emissions to total natural emissions is highest for the atmophilic elements Sn, Cu, Cd, Zn, As, Se, Mo, Hg, and Pb (Lantzy and Mackenzie, 1979). In the case of lead, atmospheric concentrations are primarily the consequence of the combustion of leaded gasoline. For many years, lead was used as a gasoline additive, in the form of an organometal compound, tetraethyl lead. When the fuel was... 

There is considerable interest in the removal of contaminants from the sites of former gas-lilling stations. The surrounding soil is contaminated not only with fuel hydrocarbon residues, but also with alkyl lead compounds that were previously used as gasoline additives. It has been shown... 

Then he swiftly produced as many different varieties of the compounds as possible, including dimethylzinc, which convinced other scientists to accept Avogadro s theory, a foundation of atomic chemistry and methyl-mercury iodide, the first of many organomercury compounds known to poison people who eat mercury-contaminated fish. Despite his skill at synthesis, Frankland did not discover tetraethyl lead, the gasoline additive that became one of the most important industrial compounds of the mid-twentieth century (Chapter 6). 

Within two decades of the introduction of tetraethyl lead, engine efficiency doubled, power per cylinder tripled, and the octane of regular gasoline rose from 55 to 75. Midgley s gasoline additive symbolized the technological wonders of industrial research and corporate America. Cheap... 

Motors support for a long-range scientific study of the poisonous gasoline additive, tetraethyl lead. Besides trouble-shooting for various Du Pont departments, Carothers published 60 papers and was listed as the inventor or coinventor of 69 U.S. patent applications during his nine years at Du Pont. Research and development were so new to American corporations that Carothers assistants drafted and he edited patent applications for Du Pont lawyers. You were supposed to be so on top of the literature that you knew whether this was something new or not.. . . Those patents are really classical scientific papers, Hill explained. Carothers considered himself unfit to be a clerk or inventor, but he dominated Du Pont s patent application process for almost a decade. 

Leaded gasoline was one of the country s top ten industrial chemicals during the 1960s it accounted for 90 percent of all automobile fuel sold in the United States. As Esso ads proclaimed, there was a tiger in the tank of almost every American car. Between 1926 and 1985, more than seven million tons of lead were burned as fuel additives. In terms of sheer volume, leaded gasoline was one of the most important organic chemicals that modern society has produced. 

The domestic use pattern for lead in 1990 was as follows lead-acid storage batteries, used for motor vehicles, motive power, and emergency back-up power, accounted for 80% of total lead consumption ammunition, bearing metals, brass and bronze, cable covering, extruded products, sheet lead, and solder, represented 12.4% the remaining 7.6% was used for ceramics, type metal, ballast or weights, tubes or containers, oxides, and gasoline additives (USDOC 1992). 

Although certain uses of lead preclude recycling (e g., use as a gasoline additive), lead has a higher recycling rate than any other metal (Larrabee 1998). An estimated 90-95% of the lead consumed in the United States is considered to be recyclable. In the United States, 77.1% of the lead requirements were satisfied by recycled lead products (mostly lead-acid batteries) in 1996. This compares to 69.5% in 1990 and 55.2% in 1980 (Larrabee 1997, 1998). 

The primary source of lead in the environment has historically been anthropogenic emissions to the atmosphere. In 1984, combustion of leaded gasoline was responsible for approximately 90% of all anthropogenic lead emissions. EPA phased out the use of lead alkyls in gasoline, however, and by 1990, auto emissions accounted for only 33% of the annual lead emissions (EPA 1996h). Use of lead additives in motor fuels was totally banned after December 31, 1995 (EPA 1996f). The ban went into effect on February 2, 1996. Atmospheric deposition is the largest source of lead found in soils. Lead is transferred... 

Lead is produced from both primary (i.e., mined ore) and secondary (i.e., scrap metal and wastes) sources, and is imported by the United States. In 1997, production from primary and secondary sources was 343,000 metric tons and 1.1 million metric tons, respectively (Smith 1998), and imports reached 265,000 metric tons (Larrabee 1998 Smith 1998). Approximately 1.6 million metric tons of lead were consumed in the United States in 1997 (Smith 1998). Of lead used in 1997, 86.9% was used for storage batteries, 7.8% was used in metal products, and 5.3% was used in miscellaneous applications (Smith 1998). Because of the adverse health effects associated with exposure to lead, its use in paints, ceramic products, gasoline additives (now banned), and solder has declined dramatically in recent years. In 1997,... 

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