One of the most important tools in modern medicine, the radiation Today it offers powerful resources for both the diagnosis and treatment of diseases. Few people know, however, that the discovery of the technique initially represented losses for human lives, and had a good deal of serendipity, or chance, to happen.
The controlled use of radiation in medicine involves applying the principles of radioactivity, a process that occurs naturally in the unstable nucleus of some atoms. And it all started when the German physicist Wilhelm Conrad Röntgen disclosed, in 1895, the existence of X ray which, it is important to remember, have nothing to do with radioactivity.
What Röntgen was really investigating was the effect of passing electric current through vacuum tubes, when he noticed a strange fluorescent glow on a screen coated with barium platinocyanide, even though the tube was wrapped in black cardboard. He realized that this was a radiation capable of penetrating opaque objects, and he called it “X” (unknown) .
Unaware that X-rays were produced only by an external stimulus, the French physicist Henri Becquerel began to research this luminescence (emission of light after absorbing energy) in some materials in nature. To test his hypothesis, he placed uranium salts on a photographic plate wrapped in black paper, and exposed them to sunlight for several hours. The plate darkened.
The discovery of radioactivity
Still celebrating the supposed proof of his theory that uranium absorbed the Sun’s energy and then “emitted it as X-rays,” the physicist tried to repeat the experiment days later. However, as the weather in Paris was cloudy, he stored the uranium samples on photographic plates in a dark place.
When he returned later, Becquerel observed that, even without having been exposed to sunlight, the plates were sensitized. Intrigued, the physicist repeated the experiment several times, varying the conditions and materials, and realized that some type of radiation was passing through the black paper and obscuring the photographic emulsion.
According to researcher Fabio Luiz Navarro Marques, manager of the Center for Nuclear Medicine at the USP School of Medicine, the “cosmos” would conspire once again “so that scientists Marie Curie and Pierre Curie married and worked together at the Sorbonne University in Paris. Using equipment developed by Pierre, Marie was able to identify pitchblende [uranita]a mineral that contained uranium and other metals more radioactive than purified uranium itself.”
From this process, the chemist explains to CNN Marie Curie discovered two substances much more active than uranium. Naming them polonium and radium the mathematician also first coined the term “radioactivity” .
For her discoveries, Marie Curie not only became the first woman to win the Nobel Prize, for Physics in 1903 (along with her husband Pierre, and Becquerel), but she was also the first person in the world to win the prize twice, also receiving the prize for Chemistry in 2011.
Marie Curie and the dangers of radiation
When she died in 1934 from bone marrow aplasia, a rare condition that prevents the production of blood cells by the bone marrow, Marie Curie was not fully aware of the harmful effects of ionizing radiation. Accustomed to carrying test tubes with radioactive isotopes in her pocket, her precious notes, and even her recipe book, are still kept in shielded lead boxes to prevent radiation from escaping.
One of the most notable cases of the risks of ionizing radiation occurred in the 1920s in the USA: the so-called “radium girls”, young women who painted watch faces with radium (to make them glow in the dark). Even though they suspected the risks of radioactive materials, the company management did not take any precautions.
Using the “lip-pointing” technique, the girls would wet the brushes with their lips to obtain a finer tip, which caused them to ingest radium. This exposure caused serious health problems for these workers, as radioactive poisoning led to bone necrosis, severe anemia and cancer.
The public repercussion of the scandal meant that stricter safety regulations were introduced in workplaces and encouraged the creation of legal instruments to hold companies accountable for the health and safety of their workers.
Paradoxically, the Manhattan Project which developed the atomic bombs that killed between 150,000 and 245,000 people (in addition to exposing 600,000 “hibakusha,” or people affected by the explosion, to long-term radiation), was the first major initiative to develop protective measures against radiation, benefiting scientists, engineers, and the 10,000 “Calutron girls” who unknowingly separated uranium-235 from U-238.
The benefits of radiation for the modern world
129 years after Röntgen’s initial “eureka” moment, we can safely say that the use of radiation has had a profound and transformative impact on life on Earth. Today, radioisotopes are used in a wide variety of processes, says Marques, the main one being the production of electrical energy in nuclear power plants.
However, the FMUSP chemist highlights that the other important area of application “is in nuclear medicine, where radioisotopes are linked to molecules, forming radiopharmaceuticals, for the diagnosis of neurodegenerative, myocardial and oncological diseases. In the latter case, they can be used to treat tumors”.
Furthermore, the expert states that radioactive sources are also used in other sectors, such as mineralogy, agriculture, in addition to the use of so-called ionizing radiation in food, to destroy pathogenic microorganisms and increase the shelf life of fruits and vegetables. In pest control, the Sterile Insect Technique (SIT) irradiates male insects, rendering them infertile.
Regarding the risk of radiation diagnostics becoming obsolete with the use of new technologies, such as nanoparticles and AI, Marques is categorical: “absolutely not, because all of these issues are related to radiation”. He mentions the case of nanoparticles that, when modified with radioisotopes, increase their diagnostic or therapeutic potential. As for AI, he sees it as an auxiliary tool.
Finally, speaking about serendipity, Marques emphasizes “that chance happens in any area of science, and only brains with the ability to interpret it and have the tenacity to seek an answer will make this chance transform into processes that benefit humanity”, he concludes.
Source: CNN Brasil
Charles Grill is a tech-savvy writer with over 3 years of experience in the field. He writes on a variety of technology-related topics and has a strong focus on the latest advancements in the industry. He is connected with several online news websites and is currently contributing to a technology-focused platform.
