This kind of elements that can be seen everywhere almost make all human beings a fool

In March of this year, a study published in the authoritative magazine "American Academy of Sciences" pointed out that the extensive use of lead gasoline containing lead gasoline has caused the intellectual level of more than half of the population in the United States to be negatively affected. 2.6 points.

Today, we talk about the story of "lead". Before the text starts, I want to repeat the familiar things, that is, the pencil we use. Although it is called a pencil, it has nothing to do with the lead. The composition of the pencil core is graphite, which is a form of carbon. So even if you like to "bite the pen" when you are a kid, you don't have to worry.

Back to the theme. Coincidentally, in a research in the "American Medical Association Magazine" in 2020, scientists scanned more than 1,000 brain structures of 45 -year -old adults born in the same town in New Zealand. The period of their growth was the peak period of lead gasoline. The study stated that the subjects of the subjects carried 5 micrograms/liters of lead at the age of 11. By the age of 45, their cerebral cortex surface area was reduced by 1 square centimeter than the control group, and the volume of the hippocampus was reduced by 0.1 cubic cubic meters. For centimeters, the value of IQ is 2 points lower, and some people also show weak cognitive ability.

Among them, participants with the highest lead exposure will also cause damage to the white quality of the brain. Because childhood is a critical period of brain development, the leading exposure during this period will have a long -term impact on the brain, and may even bring degenerative diseases in the elderly.

In the once daily life, many people are accustomed to it, but in fact, they seriously damage the human brain. For example, the once -popular lead water pipe, and the lead -containing car tail gas mentioned above. Although these lead water pipes and lead -containing gas are slowly fading out of human life, the harm they cause is like shadows, and they have been entangled with a large number of victims for a long time.

Leaded gasoline can be popular for nearly 100 years. Of course, there are compromises and helplessness, but the capital forces and supervision behind it are also difficult to blame. Why add lead to gasoline? What symptoms can people cause lead -tail gas for a long time? Can humans completely eliminate lead's pollution in the future, and even eliminate leading materials?

Lead crystal and processing of pioneer block (picture source: Wikipedia)

How does lead -containing gasoline additives appear on the stage of human history?

In the process of constantly improving the internal combustion engine, humans gradually discovered the so -called "burst" phenomenon. In the early days, the compression ratio of the combustion engine was low, and the temperature in the cylinder was not high. As long as the spark plug was not ignited, the oil and gas mixture in the cylinder would not burn. When we are pursuing a high -performance internal combustion engine, we must not help but increase the compression ratio and increase the working temperature of the cylinder. At this time, some oil and gas mixtures may spontaneously ignite before the spark plug ignition, that is, the burst of gasoline.

Dynamic map: The schematic diagram of the explosion (the left side has begun to burn before the spark plug was ignited), Source: Wikipedia

This is like when everyone is interested in racing the dragon boat, someone does not hear the chaos of the number, and it will inevitably affect the entire team. Blasting is definitely not a good phenomenon for internal combustion engines. It will not only reduce the fuel efficiency of the internal combustion engine, but also emit noise or even damage the cylinder. If you want to solve the explosion, of course, you can start with both internal combustion engine structure and gasoline itself. However, the development of the internal combustion engine structure has fallen into a bottleneck at that time, and the increase of the compression ratio was originally an inevitable way for the development of the internal combustion engine. Therefore, engineers can only find ways on gasoline.

The inventor of lead -containing gasoline additive Mikily (left) and its product packaging (right) picture source: Wikipedia Encyclopedia

Soon, Thomas Mikeli, who worked in the United States, found a compound named Simi B. This substance synthesis process is simple, the cost is quite low, and it can effectively improve the explosion -resistant shock performance of gasoline. Unfortunately, some compounds of lead elements and lead were already well -known poisons at the time, and the launch of lead -containing gasoline additives for the market would likely cause public concerns.

However, GM shows great interest in this technology. For the sake of the product to be listed smoothly, they deliberately concealed the fact that the gasoline -containing facts were concealed at the time of product naming, and called it "ethyl gasoline additives". Since the construction of the production line, many workers have become ill or even died due to lead poisoning. However, in the face of the huge economic interests of anti -explosive gasoline additives, General Corporation still ignored various safety hazards and promoted the four -year -old lead to become the most widely used gasoline additive in the past 100 years.

Lead -containing qi with inferior spots

The harm of lead -containing gasoline additives soon began to appear. During the production link, the incidents of acute poisoning of workers and chronic professional poisoning were frequent. In the consumption session, a large amount of lead waste enters the atmosphere with the discharge of automobile exhaust and enriches the area along the road. Developed countries have entered the automobile society earlier, and motor vehicle ownership has been far ahead of developing countries decades ago.

Image source: veer gallery

Among the acute poisoning incidents caused by the four -Bctoral lead gasoline additives, the most well -known and most dramatic is the trial method of its inventor Mikily. On October 30, 1923, in order to dispel the public's doubts about this material security, Mikeli specially held a press conference, and took out a small bottle of four ethyl -based lead additives at the scene, and applied it to the hand. I heard it for 60 seconds to the bottle mouth. Who knew that the conference became a "large car accident scene". A few days later, not only did a four -ethyl -based lead factory in general encountered the New Jersey government's shutdown, Mikeli himself also had severe lead poisoning symptoms. After he was taken to the hospital, he recovered it for a whole year. In 1970, a serious chronic lead poisoning incident also occurred. Liaomachi was a block of Shinjuku District of Tokyo. At that time, it was the intersection of several traffic roads, and the terrain was located at the bottom of the valley, and the air was prone to accumulation. Car tail gas meets the "bottom" terrain, making the carbon monoxide content in the area in the area at the forefront of Tokyo. This has led to the high rate of incidence of respiratory diseases in local residents, and even the saying of "gornem".

Winter car tail gas (picture source: Veer gallery)

In order to investigate the health status of local residents, medical institutions conducted detailed physical examinations of local residents. It was found that the blood lead content in the body of the inspection residents reached an average of 47.7 mg per minute, and the highest level of 138 mg was basically more than 7 times that of the rest of the country. At that time, the standard of lead occupational damage identification stipulated in the Ministry of Health and Labor and Ministry of Welfare was 60 mg per minute. Many residents in Liucho were already in a state of lead poisoning.

However, the effect of chronic lead poisoning on the nervous system is difficult to describe with specific values, after all, this may be a slow process that lasted decades. Although the above research data has a series of details that are worth scrutiny, it can generally reflect the long -term and far -reaching poisoning of lead poisoning to the human nervous system. So what kind of role does lead and the human body happen, and why does it affect human health, what are the symptoms and treatment methods after lead poisoning?

What kind of element is lead?

Lead is a widespread metal element in nature. The single quality of the lead has the characteristics of large density, easy melting, and easy processing. It is widely used in industrial and daily life. The density of the lead is about 1.4 times the iron, so the single quality of the lead is often used to make various forms of weight. Various compounds of lead have become an indispensable raw material for human beings since the era of the industrial revolution. In addition to gasoline additives, the industrial use of large lead also includes lead batteries, tin lead welds, lead coatings, lead alloy jewelry, etc. Essence

Lead bricks (left) for ray shielding materials and small lead battery (right) pictures source: Wikipedia Encyclopedia

As a toxic element, the lead does not have the risk of poisoning at all when it does not enter the body when it exists. The block material of touching lead is very safe, without too much doubt, but it is very dangerous to eat lead. Single -quality lead will dissolve lead ions under the action of gastric acid. After entering the blood, these ions will quickly flow to the whole body, causing damage in multiple organs.

In 2006, the United States had an incident that the 4 -year -old child died in the United States. A 4 -year -old boy with mild intelligence disorders went to the hospital due to sudden vomiting. At first, the doctor did not doubt the boy by mistake, and only asked the parents to bring the boy home after opening the spit medicine. Unexpectedly, the situation of the boy suddenly deteriorated two days later, and his abdominal pain was severe and accompanied by weakness. After being taken to the hospital, the boy has a series of neurological symptoms such as excitement, dyspnea, and brain edema. X -ray transverse visual examination shows that the boy's stomach has foreign bodies.

Four days after admission, the lead concentration in the boy's blood reached 180 mg per minute, and the doctor suspected the possibility of acute lead poisoning. However, the conclusion was too late. The boy had symptoms of brain death that night and died after 5 days after admission. The dissection results after the death show that the foreign body of the boy's stomach is a heart -shaped decoration on the boots, which contains 99.1%of the lead.

After this tragedy, many countries conducted many inspections on cheap metal jewelry on the market. The conclusion showed that lead and lead alloys were low in price and solid texture. Until now, some manufacturers are still used to make low -cost accessories. These accessories do not affect health during daily wear, but if they are eaten by children, they have a great risk of poisoning.

(Single quality) Lead poisoning example: (left) lead water pipe system, (right) Eat corrupt animal edible lead -elastic prey after eating prey.

Leading compounds are more likely to cause environmental harm

After speaking, the single quality of the lead, let's take a look at the health risks of the various compounds of the lead (including the lead ions dissolved in the lead water pipe) to the human body. Although the various inorganic compounds of the lead can exist in vitro, they will gradually deposit and slowly decompose once they enter the body through the respiratory tract and digestive tract. In each organs, because the kidneys and liver are involved in the metabolism of lead, the lead content is higher, and the lead content in the brain is relatively low.

The gaseous organic lead compound released in the car's tail gas is mainly through the respiratory pathway. Because it has fat -soluble, the skin is also one of the possible ways to enter the human body. Although the lead will accumulate after entering the human body, it can be excreted to a certain extent. The feces, urine, and even breathing are the ways to discharge the body. Different from inorganic leading compounds, the lead concentration in the brain after inhalation of organic lead compounds will increase significantly, which is also one of the important reasons for the effect of lead -tail gas to affect the nervous system. The influence of lead on the body: (left) In the early childhood, the history of lead exposed to the history of lead exposed to the forehead of the brain was significantly smaller (red part), (middle) special dry end line after lead poisoning, (right) reference after lead poisoning Alkaline points color red blood cell picture Source: Wikipedia Encyclopedia

The main cause of abnormality after entering the human body is that lead can interfere with the synthesis of hemoglobin. When the concentration of lead in the blood reaches 40 micrograms per division, the biochemical process related to the hematopoietic processing will begin to be disturbed, but at this time the abnormal condition in the body is not enough to develop a obvious symptoms that can be perceived in the short term. When the blood lead concentration reaches 60 micrograms per division, the indicators of multiple organs such as the liver and kidney in the body may occur abnormal. Blood lead concentration has further risen to 80 micrograms per minute, and the symptoms of the whole body begin to appear. The first manifestation is anemia and unique gray face. The nervous system will also have various performances such as headache, sensitivity, bipolar and melting.

When the blood lead content in the body rises to 150 micrograms per point, the human body is already in a state of comparable to acute lead poisoning. At this time, major systems, especially the nervous system, will have serious abnormal abnormalities. The normal function of the human brain is difficult to maintain, exercise and perception of abnormalities. Under the action of nerve paralysis, patients often show unique symptoms of handy hand.

Be wary of children's killer (picture source: Changsha Evening News)

In recent years, research has been constantly found that long -term exposure to an environment where lead content exceeds the standard, even if the blood lead concentration has not reached the risk of pathogenic disease in the traditional sense, damage in the human body, especially the nervous system damage has been produced. Therefore, this research does not put forward new conclusions, but to add some new evidence to long -term existence. Unlike other metal elements such as copper and iron, lead has no known effect in the human body and is purely toxic and harmful substances. However, due to the extensive distribution of lead in nature, humans will inevitably consume lead through various channels, which is mainly diet.

The daily leading intake of Chinese residents is different according to the region. Taking Hangzhou residents as an example, the 2014 survey shows that the lead intake of Hangzhou residents is about 80 micrograms per day. There is a lot of tolerance intake, but it is still significantly higher than that of neighboring Japan (about 20 micrograms), such as the earlier control of lead pollution.

With the introduction of more stringent environmental protection measures, it is believed that the lead intake of Chinese residents will gradually be on the world's advanced level. Therefore, it is even more important to take more comprehensive "lead" measures in various industrial categories.

The state of lead determines whether it is harmful to the environment

In fact, it is the existence and distribution form that determines the size of the lead and the environment to poison the human body and the environment, and the latter directly determines whether the leading materials can be promoted on a large scale. For example, although the industrial lead is close to 9 Chengdu for lead battery, the possibility of the leading compounds released to the external pollution environment is very low, so the lead battery has always been the first choice for manufacturing battery and UPS spare power supply. The four -Bctoral lead leaders as anti -explosion gasoline additives and tin lead welds used in the electronics industry have great environmental risks.

Although tin lead welds are low in performance and low performance, due to many welded joints on the circuit substrate, the lead alloys on the waste circuit board cannot be recycled, and the huge and consumption and waste volume of electronic products make them impossible for them to be impossible Perform harmless treatment. In the end, the circuit board accumulated in the wild garbage treatment field may continue to release lead in soil and groundwater under natural conditions. These lead will eventually be enriched by plants and aquatic animals, and then enter the human body through the food chain.

Waste circuit board (picture source: Veer gallery)

Considering the potential environmental harmfulness after the use of lead is improper, even if the four -Bctoral lead and tin lead weld have an unparalleled performance advantage, humans must wave goodbye to them. At present, only several countries and regions in the world are still selling lead gasoline. After nearly 30 years of efforts, the electronics industry has basically eliminated the use of tin lead welds in the field of civil consumer electronics. These measures have well suppressed the upward trend of lead content in the environment, and also reduces the lead content in the body through breathing and diet.

Throughout the history of the evolution of the earth, you can see that each element is a treasure given to human beings in nature. They always create opportunities for human development at some point. Although some forms of lead and lead compounds have certain human toxicity, they are still the key materials for many occasions. Moreover, as long as it is used in a scientific way, these lead -containing materials do not cause damage to the human body and the environment. In the future, human beings still need to control the leading forms to enter the environment more strictly, and at the same time, they also need to develop and use lead more reasonably to let these resources truly benefit human beings.

Produced: Popular Science China

Author: Zhang Hao

Producer: China Science Popularization Expo

references:

1. HALF of US Population Exposed to Adverse Lead Levels in Early ChildHoodhttps: //www.pnas.org/doi/10.1073/pnas.21186311199

2. One of the Worst Public Health Dangers of the Past Century Has Finally Been Eradicated

https://www.vox.com/future-perfect/22650920/leaded-gasoline-hadicated-public- health

3. Lead Exposure in Last Century SHRANK IQ Scores of Half OF Americans, Study Finds

https://www.scienceDaily.com/releases/2022/03/220307162011.htmm

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