It was not until the s, following extensive health research, that the devastating health impacts of low-level lead exposure were established. The health impacts of lead exposure in children include anemia, behavioral disorders, low IQ, reading and learning disabilities, and nerve damage. In adults, lead exposure is associated with hypertension and cardiovascular disease.
Prior to the lead phase-out in gasoline, the total amount of lead used in gasoline was over , tons per year. Congress passed the Clean Air Act in , setting in motion the formation of the EPA and, ultimately, the removal of lead from gasoline.
Novel Analytical Methods for the Determination of Fuel Oxygenates in Water | SpringerLink
EPA estimates that between and , 68 million children were exposed to toxic levels of lead from leaded gasoline alone. The phase-out of lead from gasoline subsequently reduced the number of children with toxic levels of lead in their blood by 2 million individuals a year between and The EPA is formed and given the authority to regulate compounds that endanger human health.
Lead damages the catalytic converters used in these new vehicles to control tailpipe emissions. Catalytic converters are still used in vehicles today. Lead is still used in some aviation fuels. Thanks to coordinated efforts, lead is now absent from gasoline in most of the world.
- Surface Treatment of Materials for Adhesive Bonding.
- The Open Mind: Essays in Honour of Christopher Rowland.
- A History of International Thought: From the Origins of the Modern State to Academic International Relations?
- Fuel Oxygenates and USTs.
Following the lead phase-out in the United States, the oil refining industry chose to construct additional refining capacity to produce octane from other petroleum products, rather than from renewable sources such as ethanol. RFG has an increased oxygenate content, which helps it burn more completely.
As a result, RFG lowers the formation of ozone precursors and other air toxics during combustion. Petroleum refiners were not required to use any particular oxygenate in RFG, but by the late s, a petroleum product, methyl tertiary butyl ether MTBE , was used in 87 percent of RFG due to its ease of transport and blending. In the Midwest, ethanol was a more common component of RFG. Despite its success at reducing ozone precursors, MTBE was phased out of the gasoline pool due to concerns over its solubility in water, which resulted in the contamination of water resources in numerous states.
Currently, 30 percent of gasoline sold in the United States is reformulated gasoline. Ethanol is providing the additional octane required by RFG. At the time, the U. At the same time, EPA and the U. The BTEX complex is a hydrocarbon mixture of benzene, toluene, xylene and ethyl-benzene. Commonly referred to as gasoline aromatics, these compounds are refined from low-octane petroleum products into a high-octane gasoline additive. While some volume of BTEX is native to gasoline, it is also added to finished gasoline to boost its octane rating. The total volume of BTEX aromatics in finished gasoline depends on the desired octane value and other desired fuel properties.
When faced with the removal of lead as the primary octane provider in gasoline, refiners had two available alternatives, BTEX and ethanol. The refining industry invested in additional refining capacity to replace lead with BTEX, a high-octane petroleum refining product. As a result of its substitution for lead, BTEX volume rose from 22 percent to roughly a third of the gasoline pool by In premium gasoline grades, the BTEX volume content was as high as 50 percent. In mandating cleaner fuels, through reformulated gasoline and other programs, EPA has reduced the volume of aromatics to between 25 to 28 percent of the conventional gasoline pool, though some health professionals question the safety of even these levels.
After the lead phase-out, there were early concerns regarding the BTEX complex.
Looking for other ways to read this?
Today, health research indeed suggests that even very low-level exposure to the BTEX complex, from gasoline additives and other petroleum products, may contribute to negative developmental, reproductive and immunological responses, as well as cardio-pulmonary effects. Upon incomplete combustion of the BTEX complex contained in gasoline, ultra-fine particulates UFP and polycyclic aromatic hydrocarbons PAHs are formed, which carry their own adverse health impacts even at low levels.
Both UFP and PAHs have also been linked to developmental and neurodegenerative disorders, cancers, and cardio-pulmonary effects. Considerable attention has been given to benzene in fuel, as it is highly toxic. At the same time, the partial replacement of benzene with other aromatic compounds xylene, ethyl-benzene, toluene may not be sufficient in reducing exposure to BTEX's toxic effects. The other aromatics, such as toluene and xylene, are not capped. Early automakers expressed interest in plant-based alcohol fuels, such as ethanol.
Henry Ford designed the first Model T to run on ethanol. But, at the time, gasoline was a much cheaper fuel. During the oil embargo, regular unleaded gasoline prices jumped 57 percent and routine gasoline shortages also occurred. These events, and the regulation of many air pollutants, sparked a renewed interest in fuel efficiency, electric vehicles, and renewable fuels such as ethanol, which were seen as ways to meet the new regulations and reduce petroleum consumption.
Today, the majority of ethanol in the United States is blended with gasoline to produce E10 10 percent ethanol, 90 percent gasoline. Over 95 percent of gasoline sold in the United States is E In addition to having lower lifecycle greenhouse gas emissions than conventional gasoline, ethanol is an excellent octane provider, with neat pure ethanol having an octane rating of over Discussion: MTBE is added to gasoline for a number of different reasons. It is used to raise octane levels. Motor vehicles require a minimum octane level to operate properly. MTBE has been used as a replacement for tetraethyl lead when that substance was banned as a fuel additive to increase octane levels.
The phase out and eventual prohibition of adding tetraethyl lead to gasoline was responsible for a major improvement of public health and the environment. That its replacement is still problematic should be one of the lessons learned while establishing acceptable standards for chemicals that may be used to replace MTBE.
- US Helicopter Pilot in Vietnam.
- BE THE FIRST TO KNOW.
- Everybodys story: wising up to the epic of evolution?
- CLU-IN | Contaminants > Methyl Tertiary Butyl Ether (MTBE) > Environmental Occurrence.
- Cyberspaces and Global Affairs.
- Oxygenates in Gasoline: Environmental Aspects, Book by Art F. Diaz (Hardcover) | gyqacyxaja.cf.
- Fuel Oxygenates: Environmental And Health Issues | Science Inventory | US EPA;
- Handbook of Applied Therapeutics;
An alternative solution that avoids the need for such additives is to promote the use of vehicles that do not require high octane fuels. It should be noted that using a fuel with a higher-octane level than the minimum recommended by the manufacture generally does not improve engine performance. MTBE is also used as an oxygenate to make the gasoline burn cleaner and reduce tailpipe air emissions.
ReFormulated Gasoline RFG is required in serious ozone non-attainment areas and other areas that have "opted in" to require the use of RFG to reduce pollution from gasoline burning engines. Areas that exceed carbon monoxide standards require even higher oxygenate levels and these are called oxy fuels. Gasoline is not an ideal fuel.
It consists of a mixture of liquid organic fossil-derived chemicals. Many of these are Volatile Organic Compounds VOC's which react in the presence of oxides of nitrogen, heat, and sunlight to produce ground level ozone smog. An example is benzene, a known carcinogen. When combusted, gasoline produces a variety of air pollutants such as nitrogen oxides, carbon monoxide, particulate matter smoke and soot , and numerous HAPs such as polycyclic organic materials POMs and formaldehyde which are carcinogens.
It also produces carbon dioxide, a major contributor to global warming. The physical and chemical properties of MTBE are such that releases to the environment through spills, leaks, or mishandling usually result in the rapid contamination of surface and ground water. The rapid transfer through soil means that MTBE will contaminate groundwater in incidents where gasoline does not. In addition, MTBE, unlike gasoline, is readily water soluble, making it extremely difficult to remove. Although the health effects of direct exposure to MTBE are not well known, initial laboratory tests indicate it is a carcinogen.
The presence of MTBE in water is readily detectable: a very small amount imparts a strong smell and taste of turpentine. Its presence in groundwater or surface water is unacceptable. The health and environmental risks it poses to drinking water supplies more than justify a rapid phase-out.
There are a variety of gasoline formulations that are cleaner burning and produce less evaporative and tailpipe emissions. Discussion: In older vehicles, the addition of an oxygenate promoted more complete combustion and lower air emissions. Over the last twenty years substantial improvement in combustion technology and emissions controls have been introduced incremental phases.
Since the model year all vehicles are required to have optimized combustion to an extent that oxygenates have negligible effects. As the existing fleet of motor vehicles continues to turn over, the air quality improvements that can be expected from the already obsolete oxygenate requirement will continue to diminish. The oxygenate requirement causes an additional problem. It has become an obstacle limiting the ability to maximize the total evaporative and tailpipe emissions from gasoline that could be accomplished by using different formulations without a prescribed oxygenate requirement.
Another oxygenate in common use is Ethanol. It is the chemical name for the ingredient of interest in vodka, and other fermented beverages. It also is an air pollutant. When combusted it produces additional pollutants some of which are HAPs such as acetaldehyde. There should be an immediate crackdown on leaking underground and aboveground storage tanks, spills, pipelines and other mishandling that results in releases of gasoline or its additives to the environment.
Discussion: MTBE is released into the environment primarily through mishandling or "accidents": spills, leaks, pipe ruptures, improper transfers and overfilling. The airborne MTBE also comes from fuel transfer operations such as filling up the vehicle, transfer from delivery truck to gas pumps, and throughout the process. With proper transfer technology the smell gasoline or its additives should be negligible to nonexistent. Airborne emissions of MTBE are a relatively minor contributor to groundwater or drinking water contamination as compared to mishandling.
Entities that are responsible for releases of gasoline to the environment should be subjected to heavy fines and penalties AND held strictly liable for cleanup and damages. If it is legally or physically impossible to determine responsible parties, appropriate state or federal funds should be used for immediate response to water quality problems. Discussion: Those that cause environmental problems should be held accountable.
IN ADDITION TO READING ONLINE, THIS TITLE IS AVAILABLE IN THESE FORMATS:
However, legal loopholes and other impediments often make it is very difficult, if not impossible to hold the responsible party accountable for a gasoline spill. In those cases where no responsible party can be determined or legally held accountable, the Leaking Underground Storage Treatment LUST Trust Fund can be used to help address this problem.
The LUST program is a federally funded program that is applicable to states. Some states have their own LUST or similar programs. These programs should be adequately funded. Furthermore, the criteria should be expanded to allow states to use these funds to prevent and cleanup leaks from aboveground sources.
It is important that leaks or spills be cleaned up as quickly as possible. While surface water contamination is unacceptable; ground water contamination is even more serious and difficult to clean up. State and local governments must immediately evaluate the adequacy of their inspection, training and management programs. Increased monitoring should be done or whatever measures are necessary to prevent and mitigate any problems.