Read an exclusive extract from the book "Cancer Code" 4. Carcinogens

What are the causes of cancer?This is the question to a million dollars (or should I say a billion?)).Most people, including many health professionals, would reply that cancer is caused by genetic changes.Mayo Clinic declares squarely on its website that "cancer is caused by changes (mutations) of DNA in cells".It's not strictly fair.Except in rare cases, genetic mutations are the mechanism, not the cause, of the disease.A cell that develops a number of genetic mutations becomes cancer.This is how cancer develops.But why did she develop these mutations?This is the deep cause of cancer.For example, what are the causes of lung cancer?It would be fairer to say that smoking leads to cancer rather than saying that genetic mutations in X, Y and Z cells cause cancer.

The factors responsible for the development of cancer are called "carcinogenic", and we have known them for centuries.In 1761, Dr. John Hill of London, doctor, botanist and medical writer, described the first external carcinogenic agent, a type of smoked tobacco.Tobacco was used for the first time by First Nations members.European explorers have brought smallpox to the new world and brought tobacco to the old world.I could not say which one killed the most people over time.In 1614, tobacco was largely sold in Europe, with about seven thousand shops in London only.Smoking tobacco, considered to be rustling and unhealthy, has been replaced in polished society by smoking tobacco, while a pinch of ground tobacco is inhaled, or "prized", generally after being put on the back of thehand, between the thumb and the index.(In medicine, this area is still sometimes called the "anatomical snore".) Dr. Hill described two cases of "polyps" of the nose, which he believed to be cancerous.

This is the first known description of a carcinogen, a chemical that causes cancer.Tobacco is rarely prized these days, the practice having largely disappeared with the use of the monocle and the overcoat, so that this is of limited clinical importance.

Although the association between smoking tobacco and cancer is suggestive, Sir Percivall Pott (1714-1788) provided more final evidence of chemicals causing cancer.Considered one of the greatest surgeons of his time, Pott, born in London, is an apprentice at St Bartholomew Hospital and obtains the Grand Diploma of the Court of Examinants of the Company of Barbers and Surgeons.After having undergone an open ankle fracture in 1756, he brought - as an informed observer of the disease - a new revolutionary perspective to a variety of medical subjects during his forced convalescence.We remember him for the "pott fracture" of the ankle, for "pott sore", caused by tuberculosis, and for having discovered the cause of scrotum cancer.

In 1775, Pott described the growing epidemic of scrotum cancer, which was a particular scourge to chimneys in London.The big fire in London, in 1666, had forced the implementation of new legislation in terms of fires, demanding smaller and more tortuous configurations of chimneys.This measure has reduced the risks of another major fire, but made the cleaning of these new fireplaces using long, infinitely more difficult straight brushes.In addition, the twisted design led to increased accumulation of soot and creosote and required more frequent cleaning.So the chimneys were smaller, dirty and more difficult to clean.The solution?We send children to do the job!The bitchy apprentices started from three and a half years old, but most were over six years old, only because they were considered that they were too weak, unable to work long hours, that they were too easily "s 's'extinguish ”(die).The apprentice agreement required a weekly bath, but most followed the tradition common to the chimneys of London, which was three baths per year.After all, why take a bath today if you were going to climb in a dusty, dirty and dangerous fireplace tomorrow?

A hundred years later, in 1773, an influential English named Jonas Hanway was disturbed to learn that only seven orphans out of a hundred survived more than a year.Children were often assigned to work homes, where living conditions were lamentable.Hanway has persuaded legislators to limit child labor, which forced thousands of hungry young people to live in the street.For many, the only solution, apart from starving, was to risk their lives at the top of a chimney spitting hot steam in order to brush the soot.Ramonous masters employed dozens of apprentices, as much as they could afford to feed.

There were a million horrible and painful ways of dying for bullshit children in London.They remained stuck inside the chimneys, fell high heights, stifled when the soot fell on them or burned.If they survived up to puberty, a last horror often awaited them: snack cancer.From the age of eight, children received a diagnosis of scrotum cancer.It all started with what they called a "wart of soot".If it was spotted early enough, the soot wart was cut with a razor.Otherwise, cancer invaded the skin, entered the scrotum and the testicles, then in the abdomen.It was painfully devastating and generally fatal.

It was obviously a professional risk, because scrotum cancer was extremely rare in all other circumstances.It was also quite rare outside of England, where better protective clothes were available.The soot caused scrotum cancer, made Pott, staying in the folds of scrotal skin and causing chronic irritation.When the critical situation of the branches was recognized, laws have been adopted to protect children, and the disease has disappeared once again.

Benzopyrene, a chemical produced in coal tar and the main component of the soot, was probably the carcinogenic element.Although soot is one of the best studied cases of chemical carcinogens, it would only be the first of a large number of them.

Asbestos

In some respects, asbestos was the perfect material of the industrial era.It is an abundant natural mineral that can be woven in the form of a light fabric.It is both flameanior and an excellent insulation.While the world passed from cars to horseback to steam engines, cars and large machines of the time, the need for fire -resistant and electricity material has increased exponentially.Unfortunately, he also caused cancer.Asbestos was an ideal compound for protective clothing, insulation and other home products.Asbestos fibers are flexible, flexible and easy to shape in clothing, insulation materials for walls and pipes.The Second World War generated a huge demand for fireproof materials, especially in naval ships.In North America, asbestos was often mixed in concrete and other building materials to improve safety against fire risks.He finally found his way in North American buildings, exhibiting millions of people in their own houses using insulation, heating and cooling systems.

Asbestos has been used since the time of ancient Egypt.Asbestos shroud protected the embalmed bodies of the pharaohs, as indicated in the written documents of the former Greek historian Herodotus.The ancient Romans wore asbestos in the tablecloths, the rags and the towels, which could then be cleaned by simply thrown into the fire.A good tip.

Even at this time, we recognized the toxic effects of asbestos.The Greek geographer Strabo wrote that minors slaves of asbestos careers often suffered from a "lung disease".In Rome, asbestos workers tried to protect themselves by covering their noses and their mouths with the fine membrane of the bladder of a goat.

Asbestos was useful and expensive, and human lives were cheap.So each time a flame retardant fabric was necessary, asbestos responded to the need.Flifting currency?Asbestos was used in banknotes in the 19th century by the Italian government.Flifting clothes?Parisian firefighters wore asbestos jackets in the 1850s.

The dawn of the industrial revolution made asbestos a world industry at the beginning of the 20th century.More than thirty million tonnes have been extracted worldwide in the past one hundred years, and during this time asbestos has become one of the most common environmental dangers.

Pulmonary diseases have followed the parabolic rise in asbestos in popularity.The first documented death of asbestos was recorded in 1906.During the autopsy, huge amounts of asbestos fibers were found in the lungs of a thirty -year -old textile worker;The material had stifled it from the inside.But American asbestos consumption only reached its summit in 1973, several decades after its health effects were known.Asbestos fibers cannot be seen, tasted or felt.In the absence of immediate acute health problems, exposure to asbestos can persist for many decades.The human body cannot degrade asbestos or get rid of it, and once inhaled it is constantly accumulating in the lungs, gradually causing scars.

The cancer?Yes, it was also a problem.In 1938, reports showed that asbestos caused rare cancer of the lung mucummer called "pleural mesothelioma".But recognizing asbestos as a carcinogenic and admitting it were two completely different things;Asbestos companies have fought tenaciously to refute the facts on their highly lucrative product.

In the 1940s, researcher Leroy Gardner proved the carcinogenic potential of asbestos when 82 % of his experimental mice who had inhaled asbestos developed cancer.It was more than a little worrying.Dr. Gardner was frantic to publicize his new scientific results, but his sponsor, the Johns Manville Corporation, reminded him of his obligation to silence because of his contract.According to their research agreement, the company had a right of censorship.Studies, which were initially undertaken to demonstrate the safety of asbestos, had rather proven the opposite.Consequently, for more than four decades, none of these potentially vital scientific results have emerged.The abolition of this vital information allowed companies to make generous profits.Once again, as in ancient Rome, asbestos was prized while human lives could be sacrificed.In 1973, the first trial against asbestos manufacturers was won, opening the door to others.This quickly led all asbestos producers to bankruptcy.Complaints against asbestos manufacturers are continuing, constituting one of the most important mass disputes in the history of the United States.Only the intense trials of the 1980s finally made public the heartbreaking correspondence between Dr. Gardner and his corporate sponsor.

In the 1950s, before the generalized adoption of asbestos in house building materials, the estimated reference rate of mesothelioma was 1 or 2 cases per million.In 1976, the incidence had increased to 15,000 cases per million.This is a horrible increase of 1.5 million percent of the incidence.It was estimated that men born in the 1940s had 1 % risk of developing mesothelioma during their lifetime.Deadly.Of an extremely rare, almost unprecedented disease, to cancer affecting a large proportion of the population, mesothelioma could only be attributed to an environmental cause: asbestos: asbestos: asbestos: asbestos: asbestos: asbestos: asbestos: asbestos: asbestos: asbestos.The World Health Organization (WHO) published its first warnings on asbestos until 1986, long after the dangers were made obvious.It was like closing the cage after the birds flew.

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Asbestos and tobacco were among the first known chemical carcinogens, but they would not be the last.The International Center for Research on Cancer (Circ), which is part of the WHO, keeps up to date a list of known and suspected human carcinogens classified according to the following groups.

- group 1: carcinogenic for humans

- group 2A: probably carcinogenic for humans

-group 2b: maybe carcinogenic for humans

- group 3: unclassifiable

- group 4: probably not carcinogenic for humans

Group 1 carcinogens include a wide range of artificial chemicals, acetaldehyde and arsenic with vinyl chloride.But many natural substances also appear on this list, such as aflatoxin (found in moldy mushrooms) and fine sawdust.Certain drugs are carcinogenic, such as the drug chemotherapy cyclophosphamide.Interesting - a drug used to cure cancer can also cause it.Radiation, sometimes used to cure cancer, can also cause it.Ironic.

In 2018, one hundred and twenty agents were listed as carcinogens of group 1.This is compared to a lonely agent in group 4 (Caprolactamus, used to make nylon, fibers and plastics).It's strange: there are a lot of things that can cause cancer and only one that probably does not.We will come back to this idea later.

THE RADIATION

One of the biggest scientists in the field of X -rays and radioactivity was also one of the first to die.Marie Sklodowska Curie (1867-1934), child prodigy, was born in Poland, the youngest of a family of five children.In 1891, she moved to Paris and met Pierre Curie, who became her husband and with whom she worked in a remarkable partnership until death separated them.

In February 1898, the Curia worked with pechblende containing uranium and found that it emitted much more radiation than they expected.Deduing the presence of a radioactive substance still unknown, they discovered a new element which they called "Polonium", in honor of the fatherland of Mary.Polonium was 330 times more radioactive than uranium.

The Pechblende was still radioactive even after the extraction of the polonium, while the Curia treated the remaining equipment to extract the tiny quantities of another new element.Only a few months after the discovery of the polonium, they isolated the pure radium.The notebook where Pierre Curie scribbled the word "radium", invented from the Latin word meaning "radius", is still very radioactive.Radium was the most radioactive substance that has ever been discovered.

Marie Curie received the Nobel Prize in Physics in 1903 for her discovery of radioactivity.The sudden death of Pierre, in 1906, in an accident in Paris, did not stop his prodigious scientific achievements.In 1911, she was honored by a second Nobel Prize, in chemistry this time;She remains the only person in history to achieve this double.Radium, recently discovered element, shone in darkness, which quickly captured the public attention.Soon, radium lacquered consumer products, such as wristwatches that shone in the dark, were being manufactured.Several million watch dials have been hand painted with radium by thousands of young women.Due to fine details, the "radium girls" moistened the brushes with their mouths, inadvertently ingesting the radium paint.

In 1922, it had become clear that something was wrong, while the radium girls literally began to disintegrate.Their teeth fell for no apparent reason.A dentist noted that when she was gently pushed, an entire jaw fell into pieces.In 1923, this serious bone deterioration was so well known that it was called "radium jaw".The ingested radium was housed in the jaw bones and did not cease to emit radiation which essentially burned the surrounding bones and tissues.A radium girl is dead when the tissues of her throat degenerate and she had a hemorrhage of the jugular vein.Another, walking in his house in full darkness, noted that his bones shone in the mirror.Her body had absorbed so much radium that she was downright phosphorescent, a "ghost girl".Those whose body did not fall to dust developed huge cancers of soft tissue, called "sarcomas".In the 1930s, it was notable that chronic radiation exposure caused cancer.

Nowadays, those who regularly expose themselves to radiation bear lead protective jackets;However Marie Curie and her colleagues worked day after day without any protection, in an environment bombed by the most powerful known radiation.The horrors of cancellation diseases did not spare them.One after the other, they died.The decades of exposure to Marie Curie's radiation left it with chronic diseases;Radium destroyed its bone marrow (aplastic anemia).In 1995, when the bodies of the curia were transferred to the Pantheon in Paris, so that the two could be honored among the most important historical figures in France, coffins lined with lead were used to protect visitors from their dangerously radioactive remains.They will remain in these protective cases for at least one thousand five hundred years.The personal notes and artifacts of Marie Curie, exhibited to the public, are also very radioactive.

The eldest daughter of Marie and Pierre Curie, Irene Joliot-Curie, and her husband, Frédéric Joliot-Curie, took over and started the pioneering work of the family on radiation.The two discovered artificial radioactivity, which earned them the Nobel Prize in chemistry in 1935.But Irene will not be spared, it either, by the curse of diseases due to radiation.She dies of leukemia at the age of fifty-seven at the Institut Curie, in Paris.

The risk of cancer increases linearly with the radiation dose.The radiation is classified as ionizing or not ionizing.Ionizing radiation carries enough energy to break molecular bonds and create ions, thus damaging the DNA of a cell.The cells that survive contain unstable chromosomes, more prone to mutations when the cell is replied.For decades, radiation has been classified as a carcinogenic agent of group 1.Non -ionizing radiation is less intense, so it can often be dissipated without permanently damage tissues.

Although chronic cancellation is carcinogenic, acute radiation may not be as much as it was initially feared.At the end of the Second World War, the American bomber Enola Gay dropped the first atomic bomb on the Japanese city of Hiroshima on August 6, 1945.His charge killed around 80,000 people instantly, and others died later from exposure to radiation and burns.However, the greatest concern for survivors was the latent risk of cancer due to this massive exposure to radiation.In 1950, the commission of victims of atomic bombs and the Life Span Study watched the survivors of the atomic bomb and their children during the sixty-five years.Although there was certainly an excess of cancer, the magnitude was not as terrible as it was feared.

The following graph shows the excess rate of cancer which can be attributed to the atomic bomb in the dark part of the bands.Pale areas show the risk of basic cancer (see Figure 4.1).

The survivors of the atomic bomb are generally perceived as being strongly affected by cancer, with horribly distorted children, but the reality is, fortunately, all other.Cancer levels have increased, but minimally (generally less than 5%), and life expectancy has been shortened by only a few months.The risk was real, nevertheless the magnitude was largely imagined.

All life on earth is constantly exposed to natural ionizing radiations that emanate from extra-Atmospheric space.The cells protect themselves thanks to increased antioxidant defenses and apoptosis induced by radiation.When the cells are irreversibly damaged by radiation, they undergo a "ritual suicide" (apoptosis) and are removed from the body.Let us therefore return to our initial question: what are the causes of cancer (see Figure 4.2)?

We knew that some chemical agents caused cancer.We also knew that physical agents as radiation provoked it (see Figure 4.2).But, soon, an extravagant theory was proposed: what if cancer was caused by a virus?