Living things have been fighting cancer from the earliest time. Hostile elements have always been present on the earth. Since nature changes very slowly, it has always eventually adjusted itself to the hostile elements, the cancer-causing agents. When people came along, the course of nature's adjustment to cancer changed dramatically because people are the first species to create cancer-causing agents. Early on, these cancer agents were things like soot. Soot was produced in great quantities during the industrial era.
The first time people began to be aware of cancer was in 1775 when Sir Percivall Pott linked soot with scrotal cancer in chimney workers. After this discovery, nothing happened in the way of cancer research for another hundred years. People did notice that there was a prevalence of skin cancer among workers exposed to arsenic fumes in copper smelters and tin foundries and people realized that cobalt and uranium mine workers were subject to lung cancer. These cancers came about before industrialization came on full force. When that happened in the last quarter of the ninetieth century, people began to be more and more aware of malignancies related to industrial exposure. By this time, people had recognized about twelve causes of cancer. By the time of the twentieth century, cancer-causing agents had proliferated immensely. In only two hundred years since Sir Percivall Pott, the world had drastically changed. Now, exposure to poisonous chemicals didn't just happen at work; it also happened in the home and on the streets.
The rate of cancer has rises dramatically each year of the twentieth century. In 1900, only four percent of deaths were caused by cancer. In 1959, the figure had risen to fifteen percent of deaths. Malignant disease is likely to strike two out of three American families. These deaths are not only among adults. Whereas cancer in children was unheard of in the early part of the century, by the mid-century, American school children die of cancer more than from any other cause. Scientists have even discovered that many of these children had cancer even before they were born.
The question at hand is whether poisonous chemicals cause cancer. In animal experiments, they do. In humans, leukemia is especially noted as a cancer caused by chemical poisons. Arsenic is one of the earliest chemicals known to cause cancer. In one study of a city which had been the site of arsenic ores, a scientist found that the arsenic wastes had accumulated around the mine shafts and had been picked up by streams and then had seeped into underground water to contaminate the city's drinking water. People of the region had suffered a diseased they called Reichenstein disease, one of whose symptoms was malignant tumors. The disease died down when a new water supply was introduced. People were not the only animals affected by arsenic exposure in these early cases. Livestock displayed cancerous lesions on their skin and even had internal problems like cirrhosis of the liver.
The public has often been asked to accept chemicals in the environment and promised that they are safe. A few years later, they often find out that the chemicals have been found to cause cancer. The method of testing cancer-causing agents in the U.S. has often been slow and, more disturbing, at the service of the chemical companies. If a company wants to introduce an insecticide, the Food and Drug Administration has to test it. However, even when the Administration denies the company the right to distribute the chemical, the insecticide can still get out. It happens by way of an appeal process. The company files an appeal and is often granted a compromise--a right to distribute the chemical in a limited amount for a trial period of time. In effect, the U.S. public is used as guinea pigs in these cases. Despite sound scientific evidence that proves a chemical is harmful to laboratory animals, insecticides still most often get out on the market. Years can go by before the chemical is withdrawn completely. One of the problems with balancing public health and private profit is that scientific testing can take years. Cancer often doesn't show up in a human population for many years after exposure to a carcinogen. In some cancers, fifteen to thirty years has been demonstrated to have taken place between exposure and detection of cancer.
Early on, most exposure to carcinogens happened in factories or other industrial work places. The first exposures to DDT occurred in 1942 among military personnel. In 1945, the general population began to be exposed to it. In the 1950s, a wide variety of pesticide chemicals came into use.
Most cancers are characterized by a long period of latency; not so with leukemia. When the U.S. dropped the atomic bomb on the Japanese civilian population of Hiroshima, people began to develop leukemia only three years afterwards. Some more recent cases show an even shorter latency period. In the period in which pesticides have risen in use, leukemia has increased as well. In 1950, deaths from all forms of malignancies of blood and lymph totaled 16,690, while in 1960, the figure rose to 25,400. The Mayo Clinic has a special blood department, the Hematology Department. Dr. Malcolm Hargraves and others report that the majority of blood cancer victims have a history of exposure to toxic chemicals.
One dramatic example demonstrates the relation between blood cancer and insecticides. A woman who was afraid of spiders decided to spray her basement with DDT. When she finished, she felt dizzy, nauseous and nervous. She soon felt better, however, and a few moths later, she repeated the procedure. The same symptoms befell her and she recovered a second time. A few months later, she sprayed her basement again. This time, her symptoms were much more severe and she ended up at the Mayo Clinic, where she was diagnosed with acute leukemia. She died the next month.
Medical literature in other countries supports Dr. Hargraves' theory which links chemical poisons and leukemia and other blood diseases: farmers who treat their land and then come down with leukemia, boys who work on farms which use insecticides coming down with different forms of leukemia, college students who spray their studies for ants and then come down with the cancer. These are only a few cases of a very great many which link insecticides to leukemia.
Cancer research looks at how the normal process of cell division becomes altered by exposure to chemical poisons. One scientist, Otto Warburg, studied the process of oxidation in the cell. He theorized that radiation and chemical poisoning affects the process of respiration of normal cells, thus depriving them of energy. This action could result from only a small dose, but one that is often repeated. The cells aren't killed outright, but are damaged. His theory explains the latency period of most cancers. It also explains why repeated exposures to small doses can be more dangerous than dramatic and single exposures. It also explains why the same thing that can cause cancer can also be used to treat it. Such is true of radiation. Cancer cells already have respiratory damage. With radiation or chemical treatment, they are killed off altogether.
Another path to cancer is through the chromosomes. Any mutation is a potential cause of cancer. According to this theory, a cell is exposed to radiation or chemical poison and mutates. Instead of following the body's normal rules of cell division, the mutant cell divides erratically, thus causing malignant cancer. The scientists studying the mutation theory of the cause of cancer have been able to link the process to particular insecticides which double the number of chromosomes in experimental plants. Children are especially susceptible to Leukemia because of their rapidly growing tissues.
Cancer can come about by an indirect method as well. One substance might not be a carcinogen, but can still affect the body's normal functioning so that malignancy results. Cancers of the reproductive system fall under this category. The chlorinated hydrocarbons are the kind of agent that can bring about indirect carcinogenesis. In the body, the sex hormones stimulate growth in relation to various reproductive organs. The liver acts to regulate the balance between female and male hormones. If the liver is damaged by disease or chemicals, or if the supply of the B-vitamins is reduced, estrogen builds up. In animal research, scientists have found that when livers are damaged, the animal develops tumors. These tumors result from abnormally high levels of estrogen in the blood. It's always hard to make the comparison, but many scientists believe that a similar process happens in humans. One study found that two thirds of 150 cases of uterine cancer evidenced abnormally high estrogen levels.
People are exposed to cancer-producing chemicals in uncontrolled and repeated instances. People often have multiple exposures to the same chemical. Arsenic, for example, exists in the environment of all people in many different forms from air pollution to water contamination to residues on food. Harm might also come from several different kinds of carcinogens. One chemical might act on another to affect its carcinogenicity. Water is often polluted in two ways: it contains radioactive pollution and chemical poisons. The radioactive elements can act on the chemical poisons to rearrange their atoms in unpredictable ways. Water pollution experts have become more and more concerned with the presence of detergents in water supplies. There is no way to purify water of them. They might produce cancer indirectly because they act on the lining of the digestive tract, so that the tissues more easily absorb chemicals.
Many people respond to the news that we are living in "a sea of carcinogens" with the fatalistic question "Isn't it a hopeless situation?" Many people think it would be best to stop worrying about this issue and find a cure for cancer. One scientist compares our situation with cancer today to the 19th century's situation with infectious diseases. People suddenly realized in the 19th century that their environment was pervaded by microorganisms capable of causing disease. Today, most infectious diseases have been brought under control and even eliminated altogether. This achievement happened because people worked on both ends of the problem: the prevention and the cure. Today, people hope for a wonder drug to cure cancer. They forget that the best victories over infectious diseases happened when people removed the disease organism from the environment. Today, if we devote all our resources toward a cure, the problem will remain because we will not have touched the "great reservoirs of carcinogenic agents" which continue to attack people.
One hopeful way to look at the problem is that unlike the 19th century's problem with infectious diseases, the 20th century's problem with radiation and chemical poisons is self-created. People put these agents into the environment and therefore have control over them to some extent.
Here the title refers the statistic that one in four people will get cancer. The chapter describes the medical search for the link between chemical poisons and cancer. In doing so, Carson lays out loads of evidence to show the dangers of a poisoned world. At the end of the chapter, though, she anticipates the possibility that reader's anxiety will produce fatalism, that the reader will find the problem too large to deal with and opt, instead, to ignore it. She provides a wonderful historical comparison of carcinogenic environment of the 20th century to the infectious disease-ridden environment of the 19th century, providing hope that the solution can be found with the proper perspective. People, in Carson's opinion, shouldn't rest all their hopes on a cure for cancer, but on the prevention of it through cleaning up the environment and stopping the dumping of carcinogens into it.
Clapsaddle, Diane. "TheBestNotes on A Long Way Gone".
TheBestNotes.com.
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