The vast majority of scientists dream of making a unique contribution to human knowledge, that their name be set in history along with other distinguished benefactors. Some, on the other hand, decide to put their knowledge at the service of destruction. This is the case of the physicists who have worked on the creation of nuclear weapons in many countries, or that of
Fritz Haberwho after synthesizing ammonia, allowing the creation of artificial fertilizers, participated in the development of poisonous gases for the First World War.
Other times, the scientist makes discoveries that seem valuable and beneficial, only to discover later that he has led to something quite different. he passed to
Thomas Midgley Jr. not once, but twice.
Thomas Midgley Jr. was born on May 18, 1889, in the small town of Beaver Falls, Pennsylvania, the only child of Hattie Emerson and Thomas Midgley, an inventor who had immigrated from London.
Graduated in 1911 as a mechanical engineer at the prestigious Cornell University, by 1916 he was working at General Motors where he rediscovered his passion for chemistry and tackled one of the problems that affected automobiles at the time, 'knocking' or knocking, name that was given to self-ignition that occurs when the mixture of a low-octane gasoline (low compressive strength) and air explodes earlier than it should or does so irregularly in different air pockets inside the cylinder, which slows down the engine. motor instead of driving it, producing a knocking sound. This combustion defect can damage the engine in a short time.
The idea was to find an additive for gasoline that would help make the combustion even, and Midgley dedicated himself to testing additives of prepared compounds by going through the periodic table, until someone sent him a sample of tetraethyl lead, a substance that he had created in 1853 the german
Karl Jacob Löwig. This substance allowed a greater compression of gasoline and solved the problem, in addition to being a good business since it could be produced at a very low cost.
The problem was that the lead in the substance was expelled into the environment through vehicle exhaust… and lead is poisonous. This should not have been a surprise to Midgley, because several workers of the company that was installed to produce the additive suffered lead poisoning, as did the inventor himself.
But Midgley was convinced that these poisonings were due to the large amount of lead used in the factory, but that the very small amounts of lead expelled by the engine would not represent a public health problem, and he defended this to the end of the day. his life despite the disagreement of the US Public Health Service. In the following decades, leaded gasoline would be a common presence throughout the world.
Thomas and your air conditioning
By 1930, the inventor was tackling a new problem: gases used in refrigeration, like those in the refrigerators of his General Motors company, were a hazard. Sulfur dioxide was corrosive to skin and mucous membranes, while methyl formate was highly toxic when inhaled and was also flammable. The ammonia and propane that were also used were equally dangerous and caused serious accidents when they leaked from the pipes of the devices. His mission was to find a non-toxic, non-flammable and odorless refrigerant gas that could be used in industrial refrigeration and air conditioning. Within a few days he determined that the best candidate was dichlorodifluoromethane, which was marketed under the name freon. It was the first of several chlorofluorocarbons that in later years would be used in refrigeration and air conditioning, in addition to being used as propellants in aerosols and as solvents.
For this work, the Society of Chemical Industry awarded him the Perkin Medal in 1937, which was added to other recognitions of the American Chemical Society and his inclusion in the National Academy of Sciences, which he came to preside over.
the truth lurked
Honest or not, Midgley's idea that there was so little lead released into the atmosphere that it could not cause health problems was met with increasing studies showing that the use of this metal and its toxicity, known since ancient times, , was an important factor in health problems, including heart disease, stroke and cancer, as well as affecting neurological development, especially in children. Some studies even pointed out that it reduced the average IQ of 5 to 10 points. Other calculations spoke of 1.2 million deaths a year directly caused by the additive of Midgley.
The world finally acted against leaded gasoline, and by 1984 it had been removed from US fuel pumps. The World Bank called for its ban in 1996 and the European Union banned it in 2000. In 2021 the last liters of leaded gasoline in the world were supplied to a vehicle at petrol stations in Algeria.
But if all the damage caused by lead could have been foreseen, it was not so with that of chlorofluorocarbons, which were released into the atmosphere both in the form of aerosols and when refrigeration devices emptied, in addition to the fact that their direct inhalation could cause other health problems.
Not all of Midgley's work was like this. Throughout his life he was granted 117 patents and he served in World War II researching the composition of synthetic and natural rubber and developing jet fuels. He also created a method to extract bromide from sea water.
In 1974, when around one million tons of chlorofluorocarbons were produced in the world every year, the chemists Sherry Rowland and Mario Molina published an article that correlated the emission of these substances with the reduction of the ozone layer of our atmosphere, which protects to Earth from the sun's ultraviolet rays. This layer thinned out especially at the South Pole, forming the so-called 'ozone hole'. Since 1976, the production and use of chlorofluorocarbons began to be prohibited except for medical applications and with enormous control. In 1994 the production of these compounds ceased and the ozone hole has largely recovered.
Midgley never got to see this. In 1940, at the age of 51, he contracted polio and lost the use of his legs. Always inventive, he devised a system of ropes and pulleys with which he could get out of bed and back into bed unassisted. However, on November 2, 1944, he became entangled in the ropes of his invention and died of strangulation.