Henderson, another notable agitator, also clearly wrote his reservations against leaded gasoline in a letter that tetraethyllead cannot be introduced for general use until it is proved harmless. To summarize it may be stated that an intensive industrial lobby was actually responsible to effectively stop any government regulation on lead in gasoline and leaded gasoline was approved for sale.
Numerous reports were published, the foremost among them was that of Dr. Clair Patterson, which highlighted that automobiles were the main source of environmental lead pollution and voiced concerns about the continuous exposure to the large quantities of lead.
However, this was challenged by The Ethyl Corp in Federal court. Another point to be considered at this time was the advent of the use of catalytic converters in automobiles. A catalytic converter is a device that converts harmful chemicals like carbon monoxide, unburned hydrocarbons to carbon dioxide and water by reacting with oxygen, it also reduces oxides of nitrogen to nitrogen gas.
Tetraethyl lead accumulated on these converters thus damaging them. As a result, cars with a catalytic converter preferred unleaded gasoline. Over the next decade, EPA sent out further regulations and in August , it proposed a decrease in lead content to 0.
The final phaseout occurred still later when the the U. Clean Air Act banned the sale of leaded fuel for use in on-road vehicles from 1 January It is interesting to consider the phaseout of tetraethyllead from the viewpoint of the Environmental Kuznets Curve.
As an economy progresses,initially, various aspects of the environmental quality get worse, but with further economic growth the environment gradually gets cleaner.
This is because that at the early stages of industrialization, with low income, people value material benefits more and tend to exploit the resources of nature and poison the environment. As income increases, people can become aware of the hazards of a polluted environment, and brings about regulatory measures to lower the environmental pollution.
So, it may be stated that the ban on the use of leaded gasoline in U. S was also a result of the country reaching the further end of the Environmental Kuznets curve in the later part of the twentieth century. By , the United Nations declared that it had been able to successfully phaseout leaded gasoline worldwide.
According to the United Nations Environmental Programme UNEP , worldwide ban of leaded gasoline resulted in 2 million fewer early deaths, greater overall intelligence and 58 million lesser crimes. In the United Sates after the TEL phaseout, the mean blood lead level of the population aged 1 to 75 years decreased from In the s, U.
S experienced a rapid increase in levels of violent crime. In the s it started diminishing at a steady pace. Some neurologists have also put forward the belief that the tetraethyllead phaseout has been responsible for the rise in the average IQ levels by several points in the U. S since it has in general reduced the overall brain damage throughout the population, especially in children.
It is indeed a studied fact that lead exposure has a negative effect on the intelligence quotient IQ of children. To summarise, the ascent and the decline of the use of leaded gasoline culminating in its ban stirs up the age old question; whether industrial and scientific progress for the convenience and comfort of mankind is worth the risk of a polluted environment.
But in the case of leaded gasoline, the tragedy was much greater since all the people involved in its production and sale, knew it was toxic, but still went forward with it for financial benefits.
Safer antiknock additives were available to the oil companies, the foremost being ethanol, 35,36,37 but it was not considered as it could not be patented.
The tale of tetraethyllead in gasoline provides caution about unregulated technology and how it can adversely affect the human race. At present, the use of leaded gasoline is prohibited in most countries. This work is licensed under a Creative Commons Attribution 4. This was acknowledged in Antiquity already, and this knowledge was strongly revived in the 19 th century. Lead poisoning was a well-known occupational hazard.
Acute poisoning will produce symptoms like pain, muscle weakness, nausea and diarrhoea. Chronic poisoning, which is much more common, is often difficult to establish, because the symptoms are not very specific: headache, abdominal pain, memory loss, kidney failure, decreased libido, and fatigue. There is evidence that lead poisoning may result in violent behaviour and a lower IQ see below.
In children, the effects are more severe. They may include loss of appetite, abdominal pain, vomiting, weight loss, constipation, anaemia, kidney failure, irritability, lethargy, slow development, and learning problems.
In the 19 th century, lead was used in consumer products, notably paints. Because of lead poisoning in children who had come into contact with leaded paints, the latter were banned in many countries from the early 20 th century onwards. The League of Nations banned leaded paints in So already at the start of the tetraethyl lead story, those who developed the new product could have guessed that it would be unwise to distribute large amounts of lead chloride, the end product of the incineration process, into the environment.
Lead chloride is a white crystalline powder. Incidentally: pure lead and lead oxide, normally the products of the explosion process, would quickly destroy the engine, and therefore agents like 1,2-dichloroethane were used together with tetraethyl lead, producing lead chloride, flushed into the air.
Fortunately, lead chloride although toxic, is much less toxic than organic lead compounds, including tetraethyl lead itself. Organic lead compounds accumulate in body fat and in organs like the liver. Neither do we know how much tetraethyl lead was dispersed into the environment, unaltered at the combustion process. But from the start onwards, toxic effects of tetraethyl lead were downplayed. A public conference did not evaluate alternatives, as the General Motors developers stated that there were no alternatives available.
Then already, researchers knew different. One commonly discussed agent was ethanol. No doubt, that would have been more expensive. So finally, the use of tetraethyl lead went ahead. Some researchers still tried to look into toxic effects, but their voices were drowned out by industry. Already in , the League of Nations banned leaded paints because of their toxicity, particularly to children.
It was not until late s and early s, that general lead poisoning of the environment became an issue again. Clair Cameron Patterson , an American geologist, accidentally discovered it. He had developed a method to establish the age of rocks by looking at the proportion between uranium and lead.
In an attempt to establish the age of the earth using this method, he discovered that environmental lead distorted his measurements. Being aware of the health dangers posed by lead and suspicious of the pollution caused by tetraethyl lead, he became one of the earliest and most effective opponents of its use.
In the s, Herbert Needleman found that higher lead levels in children were correlated with decreased school performance. Needleman was repeatedly accused of scientific misconduct by individuals within the lead industry, but he was eventually cleared by a scientific advisory council.
There are many reasons why this might have happened, but the economist Jessica Reyes had an intriguing thought. Children's brains are especially susceptible to chronic lead poisoning.
Is it possible that kids who didn't breathe leaded petrol fumes grew up to commit less violent crime? Reyes could test her hypothesis: different US states phased out leaded petrol at different times. Other researchers have found similar links between lead water pipes and urban homicide. You can put a dollar figure on the value of crime reduction, Reyes found. It's about 20 times higher than the cost of de-leading petrol - and that's before you count other downsides of children breathing lead, like worse performance in school.
It's a tale of disputed science and delayed regulation, much like you could tell about asbestos, or tobacco, or other products we now know slowly kill us. The problem is that people who want to ban things aren't always disinterested visionaries like Hamilton. Sometimes they're obstructive cranks. The only way to tell the difference is by conducting studies. And, as Gerald Markowitz and David Rosner point out, "For the next four decades, all studies of the use of tetraethyl lead were conducted by laboratories and scientists funded by the Ethyl Corporation and General Motors".
How Diesel's engine changed the world. Battery bonanza: From frogs' legs to mobiles and electric cars. Why the falling cost of light matters. How a razor revolutionised the way we pay for stuff. And what of the scientist who first put lead in petrol?
By all accounts, Midgley was a genial man who may even have believed his own spin about the safety of a daily tetraethyl lead handwash. But, as an inventor, his inspirations seem to have been cursed. His second major contribution to civilisation was the chlorofluorocarbon, or CFC, which improved refrigerators, but destroyed the ozone layer. In middle age, afflicted by polio, Midgley applied his inventor's mind to lifting his weakened body out of bed.
He devised an ingenious system of pulleys and strings. They tangled around his neck, and killed him. The fatal attraction of lead.
Did removing lead from petrol spark a decline in crime? Does lead poisoning make you violent? Image source, Science Photo Library. Chemist Thomas Midgley insisted that tetraethyl lead was safe. Only 49 people worked there. An aerial photograph of DuPont's Deepwater factory site, where tetraethyl lead was developed. Chemist Thomas Midgley with the Delco laboratory test engine. Risky, but useful?
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