For scientists, the most regrettable thing is that they can win the Nobel Prize, but they will not survive that day. Since 1974, the Nobel Foundation has stipulated that the Nobel Prize shall not be awarded to deceased persons in principle. Therefore, when the "God Particle", which was jointly predicted by six people in the 1960s, won the Nobel Prize in Physics in 2013, it was only awarded to two living people, and the two people equally shared the prize of approximately US$1.2 million. The verification process, which often takes more than 20 years or even half a century, has caused many scientists to miss out on the Nobel Prize. And a long wait isn't always bad. The Nobel Foundation once made a fatal mistake by being too "impatient" in awarding awards. The 1948 Nobel Prize in Medicine or Physiology was awarded to the Swiss chemist Müller who synthesized DDT (DiDT). This became a stain on the Nobel Prize's life.
Mueller
DDT, as a pesticide, was considered harmless to humans at the time, could effectively kill insects, and was cheap. With the endorsement of the Nobel Prize, DDT was promoted to the altar in the 1950s. In the fields where DDT was used, there was a bumper harvest. American farmers even sprayed each other with DDT to celebrate. After it was used on a large scale around the world, scientists discovered something chilling: DDT is actually harmful to humans and animals!
Spraying DDT to celebrate
The whole story begins in the 1930s. Before the invention of DDT, most countries faced food crises. In Switzerland, Muller's home country, crop fields are often wiped out by locusts and the people are starved of food.
Locusts
What is even more frightening is that harmful insects such as body lice, fleas and mosquitoes can serve as vectors of infectious diseases. During World War II, epidemic typhus claimed countless lives. This infectious disease caused by Rickettsia microorganisms can invade the human body through lice, fleas, and other arthropods as vectors. The main culprits are mosquitoes and farmland pests. But in fact, there were many kinds of pesticides at that time, but they were either expensive, not effective for a long time, or easily develop resistance in pests, and their effects were average. Effective pesticides are harmful to humans, such as arsenic. Muller's childhood friend died from eating fruits and vegetables that had been sprayed with arsenic.
Wouldn’t it be perfect if there was a pesticide that was harmless to humans and the environment, lethal to pests, and so cheap that African people could afford it? Whenever he thought of people living in dire straits, Muller, a doctor of chemistry, decided to regain his childhood ideal and invent an efficient pesticide. In 1935, Muller began a systematic study of pests and discovered that insects and mammals absorb chemicals differently. Following this clue, after spending 4 years and 349 failures, in September 1939, Muller found his ideal insecticide-1,1,1-trichloro-2,2- Bis(4-chlorophenyl)ethane, also known as DDT.
DDT
But the scientist who first synthesized DDT was not Muller. It is recorded that Osma, a medical scientist in Vienna, was the first person to synthesize DDT in 1874, but at that time he The chemical properties of this substance were not investigated, and its effects and values ??were not understood. The toxic mechanism of DDT is: it enters the insect body through the chitin of the insect body wall, inhibits nerve signal transmission, causes the insect's muscles to spasm or become over-excited, and eventually becomes paralyzed and dies, similar to the neurotoxin of snakes. The effects of DDT on mammals are so small that they are considered harmless.
In 1940, DDT was the first to receive a patent in Switzerland, and the Swiss government confirmed its effectiveness against potato beetles and other insects. Subsequently, DDT applied for patents in other countries and mass-produced it. The invention of DDT is tantamount to dropping a bombshell for pests.
According to data from the World Health Organization: In 1948, Sri Lanka, which did not use DDT, had about 1 million new malaria patients every year. Until 1963, when DDT began to be used, there were 18 new malaria patients every year. The effect can be described as shocking. In 1954, after the use of DDT in the United States, the unit yield of farmland increased by 60% compared with 1943 when DDT was not used. Because DDT is cheap, lethal to pests, and harmless to humans, the total amount of DDT used worldwide exceeds 1.8 million tons.
When the grain harvest is good, American farmers use DDT instead of champagne to spray the food.
Spray some DDT when swimming, the insect repellent effect is great.
Give the forest some DDT to kill the pests.
Even models in fashion magazines use DDT as a surrounding background, proving that it is safe and harmless to humans. It seemed at that time that if a person's first life was given by his parents, then his second life was given by DDT, because it solved the disease and food problems. This wave of enthusiastic pursuit successfully sent DDT to the Nobel Prize in 1948. When people were immersed in the joy of DDT, the situation changed 180 degrees.
In 1962, some scholars discovered that after using DDT, birds near their homes died one after another. They believed that DDT was the cause and called on the general public to stop using it as soon as possible. After several months of investigation, it was found that DDT can enter the human body through bioaccumulation and will indeed cause harm to the human body!
Bioconcentration
Due to the stable chemical properties of DDT, it is difficult to decompose in nature, and its concentration will continue to increase along the food chain. After testing, the concentration of DDT in the lake water was 0.000003ppm, and the concentration that reached the birds through the food chain was 25pm. The concentration increased by 8.33 million times! The circulation of nature has also brought DDT to every corner of the world. DDT can even be detected in the blood of Antarctic penguins and the snow water of Mount Everest.
Thinning eggshells
High concentrations of DDT will interfere with the calcium metabolism of birds and make eggshells thinner. Very few can hatch successfully, seriously affecting reproductive function and lifespan of birds. . DDT is a lipophilic and hydrophobic organic compound. For humans, when it enters the human body, it will be stored in fat cells, affecting human hormone secretion and having spermicidal effects. In addition, medical research has also found that DDT has an impact on liver function, is a potential threat, and may even cause cancer. DDT has been used on a large scale in the United States, causing immeasurable damage to the ecological environment and human health. The American people launched a protest movement demanding a complete ban on DDT. Some scientists believe that the use of DDT should be strictly controlled and should not be banned because of its effectiveness in fighting malaria. However, then-U.S. leader John F. Kennedy, considering the rising public sentiment against DDT and in order to increase his support for the next election, deliberately curry favor with the public and only publicized the negative effects of the DDT survey results while ignoring the positive effects. Sure enough, Kennedy's approval ratings rose.
Nixon
President Nixon also used the same method, announcing that he would completely stop the production and use of DDT, and called on other countries to ban it. In 1972, under the leadership of the United States, many countries around the world began to ban DDT, including even African countries that were suffering from malaria. In this way, it only took 25 years for DDT to win the Nobel Prize in 1948 and be banned by many countries around the world in 1972. It can be said to be "thirty years in the east of Hedong, thirty years in the west of Hexi".
However, is banning DDT really the best option? After the ban on DDT, malaria resurfaced in Africa. The number of malaria patients in one province in South Africa soared from 8,000 to 40,000. After the ban on DDT in Sri Lanka, the number of malaria patients increased by 500,000 within a year. In the past few decades, tens of millions of people have died as a result of the ban on DDT, more people than Hitler killed. Some scientists pointed out that DDT can be used as a repellent to drive mosquitoes out of the house and prevent the spread of diseases. If the concentration and scope of use of DDT are limited and only used in small amounts indoors, the incidence of malaria can be reduced by 90%. If used properly, it will not pollute the environment or cause harm to the human body.
Malaria patients
At the end of the 20th century, people began to reflect on the benefits of DDT to mankind. In 2000, there were 300 million malaria patients in the world, and more than 1 million people died from malaria every year, the vast majority of whom were Africans. In 2003, South Africa resumed the use of DDT, and within one year the number of malaria deaths was reduced by 50%. Since then, under the advocacy of the World Health Organization, more African countries have resumed the use of DDT to fight malaria.
The picture above shows the incidence of malaria in Africa in 2000 before DDT was used. The picture below shows the incidence of malaria in Africa when DDT was used in 2012, and the effect is obvious.
From the cheers when DDT was invented, to the protests when the dangers were discovered, to the reflections when DDT saved malaria patients. It is a poison that poisons the environment and animals, and it is also an antidote that saves malaria patients.
Ultimately, it's not DDT that's wrong, it's the people who use it and how they use it.