Cancer is caused by chemical substances?

In England in the eighteenth century craft chimney sweeps worked boys 7-8 years. They fit inside the chimneys and cleaned them. A significant part of these boys became ill with cancer of the scrotum on reaching 20 - 25 years of age. Then there was held the law on which to work chimney sweeps, allow a person not younger than 16 years of age. These sweeps were not ill with cancer 20-25 years, he appeared at them later, when they were 35-45 years. The development of sweeps of skin cancer of the scrotum, and not in other places of the body, because the skin of the scrotum fine, rich folds where soot may get stuck for a long time, and abundantly supplied with sebaceous glands, the selection of which facilitate the absorption of carbon black. If the chimney fell ill with cancer often working in other professions, so soot can cause cancer or, at least, to contribute to its development. But only if soot? Long known some other professions, which led to cancer. Workers are constantly dealing with coal pitch (tar) and paraffin developed skin cancer, if they for many years was engaged in this business. May be, coal tar and paraffin also cause cancer or contribute to its development? How to verify this assumption?
If the tumor can be Pereval from one animal to another, as it was shown for the first time Novinsky, we'd probably be induced swelling of the animal, if only act on it the agent, which is the cause of the tumor. If soot or coal tar cause cancer in humans, they have to cause cancer in animals.
Many researchers in different laboratories heavily oiled skin of various animals coal tar. Smeared and time, and two, and dozens of times in various places in the body. Tried to scratch the skin and RUB in it coal tar, tried many other ways. Fell wool, leather became inflamed, but cancer animals are not ill. Much later it turned out that the success of these experiments require not only suitable animal and related substances, not only art and insight of the experimenter, but l have one more thing, without which it is impossible to success in the study of cancer, is patience. In fact, it turned out that, in order rabbit appeared skin cancer is to smear his coal tar is not the week and month, and over the year, while regularly, at least twice a week. Such patient scientists were two Japanese - Yamagiwa and Ishikawa, who in 1916 managed using coal tar cause skin cancer rabbits. This was an important milestone in the study of cancer. For the first time the cancer was obtained in a healthy animal by processing it with a certain substance. Several years passed before other researchers have seen this play cancer. Then began to work, in which this "tar" cancer has undergone a comprehensive study. First single work, then dozens, hundreds, now their number considerably exceeds one thousand. Managed coal tar play cancer also in mice and some other animals.
Coal tar is a mixture of different substances. The most important thing was to determine which of them cause cancer. Earned chemists. They extracted from coal tar various chemicals, and biologists have studied their ability to cause cancer in mice. After many years of work, in 1926, it was found that cancer is caused by the substance resin, which sublimates at 800-850 degrees. Several years of intense research and obtained chemically pure substances the introduction of which laboratory animals gives them the appearance of cancer or sarcomatoid tumors. Some of these complex organic substances, such as methylcholanthrene, cause tumors in very small doses, sometimes in fractions of a milligram. Tumors appear immediately, but only after 8-10 months later.
However, different animals they occur with equal frequency. The more often this type of animal is sick tumors in natural conditions, the easier and more constant reproduced tumors of the introduction of chemicals. For example, in mice and rats whose tumors are often observed in natural conditions, the introduction of certain chemicals causes tumors in 100 percent of cases, while in Guinea pigs and rabbits that have naturally arisen tumors were less frequent, chemicals are not always lead to tumor formation. But be that as it may, chemicals certainly cannot cause disease tumors. These substances were called carcinogenic, that is cause cancer (cancer from Latin - "cancer").
N. N. Petrov and his staff in the experiments which took place in Sukhumi, similar impacts caused diseases tumors and in monkeys, which under natural conditions, cancer is rare. Swelling 4-10 years after the monkeys were subjected to an appropriate treatment.
All these facts leave no doubt that certain chemical substances introduced into the body, cause tumors. Researchers of all countries make sure of it. But it turns out that such substances can be found in the body of the patient with cancer. L. M. Sabado and his staff in Leningrad has been made of these substances from liver cancer patients and to show that they can cause cancer.
Chemical theory of the origin of malignant tumors received the most convincing evidence. Her supporters may say that the cancer occurs because the body is disturbed metabolism and formed a special cancer causing carcinogens. These substances and determine the formation of tumors. In other cases, carcinogenic substances affect the body, getting to it from outside, for example when working with products thereof.
It seemed that solved the centuries-old mystery and found the real cause of cancer. But... the joy was premature.

  • Cancer-causing substances, is too much!