Silent Spring Rachel Carson Essay Example

Silent Spring Rachel Carson Essay Example Silent Spring Rachel Carson Paper Silent Spring Rachel Carson Paper spring begins without the once-familiar sound of birdsong. Birds are disappearing from communities that once enjoyed seeing multitudes of migrating birds. Spraying against such things as Dutch elm disease and fire ants has destroyed birds by the thousands. Spraying for Dutch elm disease began in the 1950s, with the immediate and devastating result of the death of the robins and other birds that lived and nested in the elms. The birds were eating their usual diet of earthworms. The earthworms had, as usual, dined on the mulch of elm leaves that fell each autumn and the DDT used against the elm disease that would not wash off of the leaves. The DDT collected in the earthworms in high concentrations, so that when the robins ate the worms, the birds were killed. Robins that escaped death became sterile, so that they could not produce healthy young. Large numbers of deaths have occurred for 90 species of birds as a result of DDT spraying of elm trees. Mammals also feed on earthworms and may be affected, and thus also the owls which feed on the mammals. Owls and hawks have been found in convulsions or dead. Treetop birds have also died as a result of the elm spraying. The loss of so many kinds of birds is devastating, not only for people who love to see them, but for the more practical reason that the birds had previously provided natural insect control. The insects come back from the spray attacks, but the birds do not and then the insects are more numerous than before. Meanwhile, in areas of the country where natural controls of the elm disease have been undertaken, many more elms have been saved, without any destruction of bird and insect life. Another bird that has suffered extensive population reduction is the eagle. Several studies suggest that this is largely due to pollution of the eagles environment by DDT and other chemicals, which causes sterility and other devastating consequences. Studies on robins in areas previously sprayed with DDT have confirmed that DDT remains in the birds at least one generation after the spraying. Studies on the eagles Chapter 8 And No Birds Sing 27 suggest that contamination of fish, their main food, is killing them and preventing them from successfully reproducing healthy young. In England, the treatment of seeds with chemicals has resulted in widespread bird deaths. The seed-eating birds, which survived long enough to be eaten by foxes, then became poison to their predators, which also died terrible deaths. In the U. S. , the same problem has occurred with chemically treated rice; pheasants and waterfowl have been killed by eating the DDT-treated rice. In some cases, birds deemed pests are being targeted with chemicals directly, so that the bird losses because of chemicals include both accidental and intentional killings. Workers applying malathion have barely escaped death after becoming extremely ill. All these examples have resulted from the inattention of millions of people on whose behalf those in power have authorized these mass killings and poisonings. Chapter 8 And No Birds Sing Analysis Carson continues to raise the stakes as she piles on the evidence against the use of chemicals. Here she returns to the theme suggested by the books title, emphasizing the sudden silencing of so many birds. She introduces the idea that biodiversity is not only more interesting to look at but truly vital to life; part of the problem with the elm trees is that entire communities have been filled with nothing but elms, leading to mass devastation when a disease specific to those trees has invaded. She also briefly touches on some examples she will return to later in the book, such as fire ants. The theme of individual culpability by silent assent is underscored again at both the beginning and end of this chapter. Chapter 8 And No Birds Sing 28 Chapter 9 Rivers of Death Chapter 9 Rivers of Death Summary For many thousands of years, salmon have returned from the Atlantic each year and traveled up the rivers in which they were born to spawn and perpetuate their kind. In 1953 in the Miramichi River of New Brunswick, the salmon migration happened as usual. By spring 1954, these tiny fish, along with their older relatives of the previous years hatchings, were suddenly besieged by the Canadian governments widespread spraying program, which was meant to combat the spruce budworm. Along with all the insects and most of the birds in the millions of sprayed acres, the entire 1954 hatch of salmon died; five-sixths of the 1953 hatch died; and one-third of the 1952 hatch died. The budworm populations, on the other hand, continued to thrive. Repeated sprayings took place, despite evidence that spraying does not effectively combat budworm. Other places have also killed fish in their attempts to control forest insects. DDT may cause blindness in fish. Even if the fish survive the spraying, the virtual elimination of the insects that they feed on may kill them, or the fish may die some time after the spraying when they draw upon their fat stores for energy and release the DDT stored in their bodies. Efforts to coordinate sprayings to reduce fish mortality have been largely ineffective. Natural parasites can be much more effective at controlling budworm, and fish will not be killed. It is impossible that with such widespread application of chemicals to the land, no chemicals will make their way into waterways. Destruction of fish and fish habitats are great losses in themselves, but they are also a loss to the millions of Americans who enjoy sport fishing. Commercial fisheries will also be affected because poisoned fish are not a source of food, and reduced numbers of fish reduce the fishermens income and the amount of fish available as food. Numerous examples of fish kills across the U. S. are given. Many attempts to control fire ants have resulted in massive fish kills. Insecticides used against insects that feed on cotton have killed many fish in the South because of heavy rains following heavy application of Chapter 9 Rivers of Death 29 chemicals to the cotton fields. Farm ponds are particularly susceptible to poisoning because of their proximity to chemically treated fields. In some parts of the world, fish from farm ponds are a vital source of food for humans. Where large spills of chemicals have migrated into streams and rivers, the deadly effects have occurred hundreds of miles away because the water has carried the chemicals downstream and into the sea. Creatures other than fish have been killed in devastating numbers; one example is the fiddler crab, which plays a vital role as a source of food to numerous other creatures, as well as a scavenger, mud aerator, and source of bait for fishermen. Some chemicals can kill animals such as shrimp at nearly undetectable levels, even half of one part per billion. The ultimate effects of the pollution of virtually all of our waterways with chemicals, some of which are unknown because they are formed by the interaction of different substances, are unknown and unpredictable. If even a small fraction of the money spent developing increasingly toxic chemicals would be diverted to research on natural methods of environmental control, perhaps our waterways could be saved. Chapter 9 Rivers of Death Analysis As she did with the birds in the previous chapter, Carson uses numerous examples of fishery devastation to build her case. The examples are shocking and convincing. The reader is left to wonder how his drinking water and favorite swimming or boating location can possibly be safe, considering the havoc wreaked on the poor fish. Carson is piling on the devastating facts as she mounts a thorough attack against any further use of deadly chemicals upon the environment. Once again, she calls on her readers, the public, to educate themselves and demand action and conscience from the authorities who are poisoning the environment. She repeats her theme of alternatives to deadly chemicals. Chapter 9 Rivers of Death 30 Chapter 10 Indiscriminately from the Skies Chapter 10 Indiscriminately from the Skies Summary Carson recalls the World War II origin of widespread spraying of chemicals as a result of the new organic insecticides and a surplus of airplanes. Before the war, such chemicals had been handled with extreme caution, and now they were dropped from the sky, in many cases without warning to the people living below. This chapter details two examples of spraying campaigns that had widespread and devastating consequences. The first example is that of the gypsy moth. Despite successful natural controls of the moth in the northeast, a program of eradication of the moth by chemical spraying was begun in 1956. The program began with the spraying of nearly 1,000,000 acres. Despite complaints and strong opposition, the next years praying included 3,000,000 acres. Many of the areas sprayed were residential, despite the fact that the gypsy moth is strictly a forest insect. People and animals were sprayed directly. Milk from cows in and near sprayed areas was contaminated. Garden produce was ruined. Many lawsuits were pursued, and some were won by those whose produce, land, and livestock had been contaminated. The number of acres sprayed was severely reduced by 1961, but evidence showed that the gypsy moth had not been affected at all. In the South, a program was launched against fire ants. Despite the fact that the fire ant posed no real problem to anyone, other than as a minor annoyance, a massive program of eradication was begun, preceded by a program of government-disseminated information about the killer fire ant. Some 20 million acres were to be sprayed. The claims made by the U. S. government about the fire ant were later entirely discredited. The fire ant does not destroy crops; in fact, it is known to eat insects that do destroy crops. The fire ants mounds actually serve to aerate soil, Chapter 10 Indiscriminately from the Skies 31 nd despite government claims at the time, fire ants do not kill people or birds. Despite numerous protests from environmental experts, conservationists, and entomologists, the spraying program was begun in 1958. In many areas sprayed, almost every form of life was killed. Carson gives numerous specific examples from different areas where the spraying was done. Farm animals stopped producing healthy young. The prescribed precautions i ssued by the government are by no means adequate to protect people and animals from contamination by the deadly chemicals. The government ignored existing findings which showed the chemical used to be deadly. Heptachlor, one of the chemicals used, changes form once it enters the environment or an animal to become heptachlor epoxide, which is even more deadly than its original form. The states in the sprayed area began protesting the continuation of the program. In many areas, there are more fire ants than before the spraying began. Florida has abandoned broad eradication in favor of local control. Local control, which is 90 to 95 percent effective, costs $. 23 to $1. 00 per acre; the mass spraying costs about $3. 0 per acre, is terribly destructive, and does little to combat the fire ants. Chapter 10 Indiscriminately from the Skies Analysis Here Carson uses two of the most egregious examples of out-of-control government spraying to show the far-reaching consequences of such programs. In both cases, the pest in question was not controlled even after massive chemical attacks, whereas countless other creatu res were killed or sickened. This chapter concentrates on building up highly specific evidence and ends with a reminder that methods other than spraying millions of acres at a time are more effective and much more cost-effective. Carson leaves the moral conclusions to her readers this time instead letting the gruesome and appalling facts speak for themselves. Chapter 10 Indiscriminately from the Skies 32 Chapter 11 Beyond the Dreams of the Borgias Chapter 11 Beyond the Dreams of the Borgias Summary This chapter is titled Mass spraying is not the only source of chemical contamination of our world. Indeed, most peoples chemical exposure comes little by little, day by day, rather than all at once as a result of mass spraying. Most people have no idea what dangerous chemicals they are encountering in their daily lives. The insecticide aisle at the store is presented as innocuously as the rows of pickles and laundry detergents, and many poisons are even sold in glass containers which, if dropped, could expose people to highly toxic levels of deadly chemicals. Package warnings are printed in tiny type and have been found to be largely ignored by consumers. Household poisons include products such as insect sprays, insecticide-impregnated shelf paper, insect-repelling body lotions, insect-killing floor wax, bug-killing clothing applications, and electronic devices that emit odorless poisons into the air. Gardening poisons are available for every imaginable purpose, with increasingly easy-to-use devices available to apply the poisons to lawn and garden. One survey indicated that fewer than 15 percent of consumers were aware of the warnings printed on chemical packaging. Most consumers see only the pictures on the packages, which portray happy families romping on their chemically treated lawns. Chemical residues in food are another source of gradual buildup of lethal chemicals in human body tissues. Only the most remote locations (such as near the Arctic Circle) remain immune to chemical contamination. Because almost all foods contain some level of such chemicals as DDT, human exposure is enormous in the aggregate. Meats and foods derived from animal fats contain the largest amounts of these chemicals because the substances are fat-soluble. Fruits and vegetables are also contaminated, and washing does not remove the chemicals. Cooking does not destroy them. Chapter 11 Beyond the Dreams of the Borgias 33 The government establishes legal limits for chemical contamination, but these limits are meaningless; the safe residues in or on all the foods we eat quickly add up to unsafe levels as we eat the foods and the chemicals are stored in our bodies. Also, there is little enforcement, so the allowable levels are frequently exceeded, either intentionally, ignorantly, or accidentally. Only interstate commerce is regulated, and most states laws about chemical contamination are grossly inadequate so food grown and sold within a state may be highly contaminated. The total exposure of each person to the most dangerous chemicals cannot be measured, so safe levels in individual foods are truly meaningless. Also, some chemicals are released for general use before their effects are known. With government oversight severely limited, even going to a zero tolerance policy is meaningless because the force of inspectors is far too small. Public education and awareness must be increased, and less-toxic chemicals must be used in place of the highly toxic and deadly chemicals. Non-chemical methods of insect and weed control must be explored and put into wide use. Until that time, human beings live as if guests of the Borgias. Chapter 11 Beyond the Dreams of the Borgias Analysis Carsons two references to the Borgias a medieval Italian family whose members were known for their murdering, poisoning ways serve as thematic bookends for this chapter. Carson extends her previous call to action to consumers by providing evidence of the extreme ignorance with which most people use deadly chemicals. Having accumulated the disturbing facts about chemical contamination of the environment in previous chapters, here Carson oncentrates on the most basic human need food and the enormous and largely unknown threat chemicals pose to our food supply. As if the silencing of birds and the widespread destruction of wildlife and ecosystems has not served as enough of a wakeup call, here Carson begins to build her case by concentrating on the direct effects of the deadliest chemicals on human beings. She again concludes by reiterating the need to eliminate the u se of deadly chemicals altogether in favor of more natural controls. Chapter 11 Beyond the Dreams of the Borgias 34 Chapter 12 The Human Price Chapter 12 The Human Price Summary This chapter is titled Public health problems used to be caused by diseases such as smallpox, cholera, and plague. Infectious disease has been largely controlled through improved living conditions, better sanitation, and miraculous drugs, but now we have caused a new kind of public health crisis by introducing dangerous radiation and chemicals into our environment in huge quantities. The results of our actions in bombarding our planet with these unpredictable substances are equally unpredictable. Previous chapters have shown how pesticides have already drastically affected the water, soil, and food, as well as many species of wildlife and livestock and how pesticides affect people in both the short term and long term. Long-term effects are easy to ignore as long as they are invisible, but they are there nonetheless. Our individual bodies have a kind of ecology, just as the larger environment does. The effects of tiny amounts of chemicals on this minute ecology can be enormous. One changed molecule can affect the entire body system. It may be impossible to tell what is cause and what is effect because there may be years between the two. Chemicals that store themselves in fat may affect many processes in the body, right down to cellular function. The human liver filters many of the poisons to which we are exposed; over time, the liver may become damaged by these poisons from which it protects the body and thus become less capable of performing its function. Hepatitis and cirrhosis are increasingly common. The nervous system is highly susceptible to damage by the chlorinated hydrocarbons and the organic phosphates. Individual sensitivity to the various toxic chemicals is extremely variable, making the establishment of safe levels meaningless. Human beings are exposed to many different substances, some of which interact with each other in unpredictable ways, sometimes increasing their toxicity enormously. Carson gives a number of specific examples of drastic effects of chemicals on individuals nervous systems. The temporary elimination of some insects will continue to result in horrific and permanent Chapter 12 The Human Price 35 physical trauma, as long as we choose to use chemicals that directly affect the human nervous system. Chapter 12 The Human Price Analysis Once again Carson uses the technique of accumulating greatly detailed examples to make her point. Here she cites a number of instances of the severe effects of chemical poisoning on individuals, many of whom were permanently disabled by their exposure to allegedly safe substances. She begins by drawing the comparison between the ecology of the outside world and that of our individual bodies and pointing out that the intricacy of the planets ecosystems is at least matched and likely exceeded by the minute and largely mysterious intricacy of our bodies. In previous chapters she has convincingly portrayed the eventual doom of the earths various environments as a result of widespread chemical use; here she extends the reach of destruction to our very selves, and again points the finger back at humans for being the agents of that doom. Chapter 12 The Human Price 36 Chapter 13 Through a Narrow Window Chapter 13 Through a Narrow Window Summary The narrow window referred to in the chapter title is the tiniest structure in the human body. Seen from far away, it reveals only a sliver of light nothing more, but viewed at extremely close range, the smallest molecule reveals a whole universe of relationships and understanding of the incredibly intricate structure of the entire world not merely the organism that houses that molecule. Only recently has research revealed the indispensable function of cells in producing the energy required for life to continue. Without functioning cells, even our organs are useless, for cellular oxidation is the basis of all life function. Many of the chemicals we apply indiscriminately to our environment act to disrupt the vital cellular function that keeps us alive. This field of study is so new that those who were medically trained prior to 1950 may not be able to realize its extreme importance and the terrible hazards involved with widespread use of chemicals. Every cell in the body is involved in producing energy. Our cells are tiny chemical factories, taking in carbohydrate fuel and converting it in a complex process of many tiny steps into energy. Only since the 1950s have mitochondria, the minute structures within cells that do so much of the work, been understood and appreciated for their extreme importance. Mitochondria contain enzymes that accomplish the work of energy production. Adenosine triphosphate (ATP) is the form of energy produced at each stage of the mitochondrial process; its ability to transfer energy from one place to another within the body is the secret to physical life. It is the currency of the life process. Without ATP, life would cease; essentially, organisms would burn themselves out because energy would be burned but not transferred, halting the cycle that keeps living things going. Chapter 13 Through a Narrow Window 37 Radiation and a number of chemicals easily serve to disrupt the energy-transferring process. There are a number of ways these substances can adversely affect the enzymes involved in the cycle of oxidation. An increase in such disasters as congenital deformities and the cessation of fertilized egg cell division has been noted, and as of 1961 the Office of Vital Statistics was conducting studies based on the increase in malformations at birth. The reproductive systems of all creatures are adversely affected by DDT and other chemicals, so that this drastic disruption of the universal currency of energy affects the capacity of all living things including humans to reproduce successfully. The problem is not merely one of reduced reproduction, but of possibly severe damage to our very genes. Our genes carry thousands of years of adaptation and evolution to us, so that in theory each successive generation is more successful than its predecessor. Chemicals that act upon our genes can cause sudden mutations, producing new and undesirable changes in subsequent generations. Cell division is the basic process of life creation for everything from amoebae to humans, but mutations as a result of the sudden influx of chemicals into our environment threaten this process that builds upon millennia of gradual adaptation to infinitesimal change. At the cellular level, life cannot cope with the onslaught of chemicals. Our understanding of chromosomes is extremely new from the perspective of the millions of years life has taken to reach the present, and our understanding of the effect of chemicals on chromosomes barely exists. Nevertheless, we bombard our environment with these chemicals; and now we are seeing the drastic effects they have on the most fundamental processes of all life. A number of examples are given of drastic mutation because of chemical exposure. Various chromosomal abnormalities discovered in humans are examined. We are now filling our environment with chemicals that have the power to alter our chromosomes and so alter the path of our genetic heritage, which is the result of millions or even billions of years of evolution. Chemical makers are not required to test their products for their effects on genetics, so they do not at our peril and the peril of future generations. Chapter 13 Through a Narrow Window Analysis Chapter 13 Through a Narrow Window 38 Carson again uses the technique of moving from a micro view to a macro view. She begins this chapter by focusing on the tiniest pieces of life, the cells and mitochondria and enzymes that function to keep energy flowing and life going. She builds upon previous chapters emphasis on the drastic effects of chemicals on living things, now explaining the intricate processes of the cells and microscopic biological factories that enable us and all creatures to live. Having explained the complex and finely tuned process, she then explains the drastic effects radiation and chemicals have on the process. Then she builds further upon that foundation, explaining the ewly understood function of chromosomes and the potentially dire effects of chemicals upon these building blocks of life. She ends this chapter as she has ended previous chapters, with a call to action that points out how we are only killing ourselves with our indiscriminate use of chemicals, but she builds upon this, too, by pointing out that damaging our chromosomes hurts not only us but also generations to come. Our irresponsible actions affect not only our present and future, but the very existence of humanity in the long term. Chapter 13 Through a Narrow Window 39 Chapter 14 One in Every Four Chapter 14 One in Every Four Summary Cancer has existed for so long that we do not know when it was first recognized. There are naturally occurring substances that cause cancer, such as radiation and arsenic. Life adapted to these threats, which are relatively few, but human beings alone among the planets creatures have the ability to create carcinogens, which cause cancer. Soot is one carcinogen. The industrial era has brought many more. Because life, including human life, adapts to environmental changes extremely slowly, the carcinogens that man has created relatively recently in the span of history can have drastic effects on humans, as well as other creatures. Only since 1775 has the connection between external agents and the existence of cancer been recognized, and it was not until the latter part of the nineteenth century that various cancers were traced to exposure to certain chemicals. There has been a huge increase in the incidence of malignancy, and in our awareness of it, in fewer than 200 years. The American Cancer Society estimates that two out of three families will be stricken with cancer. Only 25 years ago, cancer in children was rare; now more American children die from cancer than from any other disease. Animal experiment evidence has shown that as many as six of the pesticides Carson has been discussing are carcinogens. Others are thought to produce leukemia in humans. Still others may be indirect causes of malignancy. Arsenic is one cancer-causing substance. It has entered water supplies as a result of gold nd silver mining and has caused regional outbreaks of numerous disorders, including malignant tumors. The widespread use of arsenic compounds as pesticides begs the question of when more such regional outbreaks of arsenic-related cancers and other diseases will occur. Not only humans but other animals, from sheep and deer all the way down to bees, have been known to develop arsenical diseases. Chapter 14 One in Every Four 40 A chemical widely used to kill mites an d ticks was eventually shown to cause cancer, but meanwhile, many thousands of people and other creatures were exposed to it. Several years elapsed before the Food and Drug Administration instituted a zero-tolerance policy on the chemical; before then, residues of this known carcinogen were allowable in food. DDT and other chemicals have been shown to cause cancer, yet these substances are still in use (in 1962). Some of these chemicals take many years to produce cancer, so that what may seem a safe level is really a level that will, eventually, rather than immediately, kill those exposed to it. Unlike most cancers, Leukemia is a cancer that develops quickly. Since modern pesticides began to be used, the occurrence of leukemia has been increasing. Other cancers also have been shown to be the result of chemical exposure. Several examples are given of individuals who developed leukemia after direct exposure to pesticides. The mysterious origins of cancerous cells are explored. Cancer appears in many different forms, and it is assumed that there are many different causes. One theory, the Warburg theory, is discussed involving damaged cells that survive through fermentation rather than respiration. This theory accounts for many of the huge differences among different species experiences with cancer, such as variable cancer growth rates. It also may explain why repeated small exposures to chemicals may be more dangerous than one single blast. The latter might kill cells completely, while the former may damage them only to the point that they become cancer-creating cells. The standards Warburg established show that most pesticides are perfect carcinogens because they interfere with the process of oxidation so vital to continued cell health. Another theory of cancer involves damaged chromosomes. Again, chemicals can easily damage chromosomes and so contribute to cancer creation and growth, or chemicals may cause mutations, which then foster cancer growth. Many chemical pesticides cause chromosome doubling, which can cause major physical problems, including cancer. Certain chemicals are drawn to bone marrow, and thus are very likely to cause leukemia in people exposed to them. Children who are growing quickly provide ideal environments in which malignant cells can multiply. Chapter 14 One in Every Four 41 Cancer may be caused by a chemical indirectly. Some chemicals affect sex hormones, which in turn adversely affect the ability of the liver to resolve hormonal imbalances. This can lead to an excess of certain hormones, which at elevated levels will cause cancer. Even exposure to very low amounts of the chemicals may affect the livers ability to keep hormones in balance. Human beings are exposed to multiple chemicals that cause cancer. These exposures are uncontrolled. Exposure to certain substances may happen in many different ways, each one of which alone may be insufficient to cause harm; but in the aggregate result in cancer. Other substances may cause no harm until a person is exposed to both of them, so that their effects are combined, or one chemical may increase the danger of another substance even something apparently innocuous, such as laundry soap. Cancer may be caused in a two-step process involving exposure to radiation and later to a chemical. Public water supplies are now frequently contaminated with detergents, which alone are not carcinogenic but can increase the susceptibility of certain body tissues to chemicals that cause cancer. We live in a sea of carcinogens, and some people approach this dire situation with the fatalistic view that we should concentrate on finding a cure for cancer because it is inevitable many people will develop the disease in our contaminated environment, but the better approach is twofold: cure as well as prevention. Just as we conquered many infectious diseases by improving sanitation and producing miraculous drugs, we must conquer cancer by finding a cure and eliminating the environmental poisons that cause cancer. Medical experts believe that even if a cure were found, the rate of new cancers would far outstrip the rate of cured cancer patients. The good news is that humans have the ability to remove carcinogens from the environment, in contrast to a rampant infectious disease that humans did not introduce into the world. By eliminating most of the carcinogens from our environment, we could greatly reduce the one in four statistic of cancer affliction. The search for a cancer cure must continue for the sake of those who have already been exposed, in some cases over decades, to dangerous chemicals likely to cause cancer. For those not yet affected and for those not yet born, we can help prevent cancer by removing the substances that so clearly cause it. Chapter 14 One in Every Four 42 Chapter 14 One in Every Four Analysis Having developed the theme of chemical destruction to living cells in the previous chapter, Carson here elaborates by discussing the proven link between chemical exposure and cancer. For many people in 1962, this connection would have been relatively new because extremely dangerous chemicals were still being sold for household use as though they were innocuous to all but the targeted insects or unwanted plants. Once again, Carson uses extensive scientific evidence, including figures and quotes from medical experts, to build her case. She explains how chemicals are understood to cause cancer in cells again, relatively new information at the time. The major point of this chapter is that many cases of cancer could be avoided simply by eliminating many of the man-made carcinogens from the environment. Carson is again pointing out the obvious solution, which also happens to be the best moral choice: humans must stop poisoning themselves and the generations of the future. Chapter 14 One in Every Four 43 Chapter 15 Nature Fights Back Chapter 15 Nature Fights Back Summary Despite our efforts to control insect populations by mass application of new chemicals, the insects keep coming back. Insects are genetically adapting to the chemicals we use they are becoming resistant, but even worse than that, our chemical attacks on insects have weakened entire ecosystems, so that the natural enemies of the targeted insects are destroyed, along with the targets. This creates an ideal environment for the unwanted insects to reinfest an environment where their unfettered reproduction will not be challenged. Humans have been ignoring the powerful forces at work in the balance of nature and arrogantly asserting their dominance, which actually shifts the balance against them. Humans have overlooked two critical facts: first, nature provides the best ways to control insects; and second, a chemically weakened environment opens the door to explosive insect repopulation. Insects are controlled by limitations on the amount of food available to them and by other insects often an ongoing struggle for survival that is completely invisible to most humans. Our lack of understanding has contributed to our arrogant and grossly overzealous application of chemicals to the problem of insect control. If we worked at understanding the balance of nature, we could use its secrets to control unwanted insects without doing harm to our environment and ourselves. Some insects hunt others; some insects are parasites to others; some feast on aphids by the hundreds. Many insects are our friends, yet we have killed them along with the unwanted insects by broadcasting lethal chemicals across thousands of acres of insect habitat. The balance of nature has already turned against us and will continue to do so as long as we continue to kill the good along with the bad. Chemical battles against spider mites, red-banded leaf rollers, codling moths, and cotton-feeding insects have resulted in explosions in their populations. Likewise, chemical attacks on insects such as the fire ant and the Japanese beetle (see Chapters Chapter 15 Nature Fights Back 44 10 and 17) resulted in sharp increases in the crop-destroying enemies of those insects: the sugarcane borer and the corn borer. Trying to eliminate one destructive insect in these cases resulted in a huge increase in an even more destructive insect. Ironically, the extremely destructive corn borer is easily controlled by the introduction of its natural insect enemies which cannot survive intense chemical attack. In the 1870s in California, a scale insect highly destructive to the citrus crop was controlled by the introduction of vedalia beetles, a parasite of the scale insect. Then in the 1940s, chemicals began to be used for insect control in the citrus orchards, wiping out the vedalia in many areas. The scale insect quickly reasserted itself, and many expensive crops were destroyed. Similar examples are given of cases involving disease-bearing insects, in which the insects natural enemies were destroyed by manmade chemicals applied indiscriminately. Chemical companies give enormous amounts of money to universities to support further chemical research, but hardly any money is given for research on natural, biological controls. Natural controls do not provide the chance of making a fortune, but they are the only way the planet will survive in balance. A program of natural controls in Nova Scotia has proven that expensive chemicals are not necessary. Human beings must give up their arrogance and learn to work with nature rather than battling against it. Chapter 15 Nature Fights Back Analysis Here Carson returns to the theme of natural insect control, building upon it by pointing out how poorly chemical control has worked. Indeed, in many cases chemical control has resulted in renewed and even greater outbreaks of unwanted insects. Carson continues using the technique of piling fact upon fact and example upon example to build her case. She continues to add examples of the arrogance and apparent stupidity of those who apply huge amounts of chemicals with disastrous results even in some cases after natural controls have been instituted and used with great success for many decades. The chapter ends on a positive note, with a glowing example of natural insect control that has the added advantage of being much cheaper Chapter 15 Nature Fights Back 45 than chemical control. She again sounds the warning that humans must stop poisoning the world and instead must learn to work with the amazingly intricate checks and balances provided by nature. Chapter 15 Nature Fights Back 6 Chapter 16 The Rumblings of an Avalanche Chapter 16 The Rumblings of an Avalanche Summary As humans continue to subject the entire environment to intensive chemical spraying, weaker insects are being killed off, and stronger insects are becoming resistant to the chemicals. Earlier, pre-DDT-era chemicals had become ineffective against some insects; Car son cites several instances. Post DDT, insects began to become resistant to chemicals more quickly. Now people interested in combating disease-carrying insects are realizing the seriousness of the situation because insects carrying deadly diseases grow to be immune to chemicals. This chapters title comes from a quotation by a scientist who says the rapidly growing list of insects that have developed resistance to chemicals may be the early rumblings of what may become an avalanche in strength. Resistance can develop very quickly. Many insects carry infectious diseases that are deadly to humans: mosquitoes (malaria, yellow fever), houseflies (dysentery and eye diseases), lice (typhus), fleas (plague), tsetse flies (sleeping sickness), ticks (fevers), and many more. The use of chemicals to control these insects is no longer working, and indeed may have destroyed the natural forces that could be put to use in combating these disease carriers. The insects persist in developing resistance to each successive new chemical. A number of examples are provided of insects repeatedly developing resistance to multiple chemicals. In many cases the diseases the insects carry have regained a foothold because of the failed chemical control of the insects. In some cases, application of the chemicals has actually increased the population of the chemical-resistant insects. Many cases of chemical-resistant insects have cropped up in the U. S. , including the salt-marsh mosquito, house mosquito, wood tick (vector of spotted fever), brown dog tick, and German cockroach. Agricultural pest insects have also begun to develop Chapter 16 The Rumblings of an Avalanche 47 resistance to chemicals intended to control or eradicate them. It is unrealistic to expect to stay one chemical step ahead of the insects forever, yet that seems to be the approach of many in the chemical industry and farming. The development of chemical resistance is a perfect illustration of natural selection. The weak insects are killed while the tough insects survive and propagate, creating more insects with the tough characteristics. Scientists do not really know how insects develop resistance. Some develop resistance within a few months, while others take up to 6 years. Some people ask whether humans could develop resistance, but this is completely unrealistic; human generations last about 33 years, while several insect generations come and go within a month or so. Humans simply dont have time to wait hundreds or thousands of years until they are able to develop resistance. We must change our approach to the use of chemicals for attempted insect control. Chapter 16 The Rumblings of an Avalanche Analysis This chapter serves as the denouement or crucial turning point in Carsons carefully crafted argument: not only do chemicals harm the environment and human beings, but ultimately they do not even work against the insects they are intended to destroy. As in earlier chapters, she augments her argument with layers and layers of frightening facts. She pounds home the conclusion that the only outcome to greater and greater application of chemicals is total decimation of the planets life, and she quotes a Dutch scientist as a sort of voice in the wilderness, proclaiming the desperately needed switch from chemical to natural means of insect control. The quotation asserts that humans arrogance and ignorance will be their downfall, and that what is needed is patient cooperation with the powers of nature. Chapter 16 The Rumblings of an Avalanche 48 Chapter 17 The Other Road Chapter 17 The Other Road Summary In our use of ever-increasing levels of dangerous chemicals in our environment, we have been traveling a road that seems easy but will end in disaster. The other road of this chapters title is the path of non-chemical control of unwanted insects and plants. Only by this other road, the one less traveled by, can we ensure our planets survival. It is up to us to assert our right not to be poisoned. A huge variety of alternatives to the dangerous chemicals used ineffectively against insects is available. Whether they are already in use or in laboratory development or exist so far only in the imaginations of scientists, they are biological solutions based on the whole of nature and its intricate network of so many different kinds of life. It is becoming increasingly clear that insecticides are more harmful to humans than to the insects we have sought to control with these chemicals. One alternative method of insect control is sterilization, in which sterilized males of the species are introduced into the environment. When the sterilized males mate with females, the life cycle is interrupted, and a whole generation of insects is eliminated. Populations of pest insects such as the screw-worm have been wiped out with the method of disseminating large numbers of sterilized males. A number of other species are being tested for susceptibility to control by sterilization, in hopes that populations of disease-carrying insects, such as the tsetse fly, may be greatly reduced, thus improving healthful living conditions for thousands of humans and livestock. Experiments are being conducted to test various methods of insect sterilization, some of which are chemical. We must exercise extreme caution, however, because widespread use of these new chemicals might put us in even deeper trouble that we are already in. Chapter 17 The Other Road 49 Other biological means of insect control being studied include methods that use insects own processes such as venoms, attractants, and repellants against them. Scientists are studying the chemical makeup of these substances, as well as of insect hormones. One success story is the creation of an artificial gypsy moth male-to-female lure; the fake lure is used to bait traps that capture the males for census work. Such a false lure might also be used to control the moths population. Another possible way to control some insects is through manipulation of their extreme sensitivity to certain sounds. Still other biological means of insect control have been around for many years. These involve manipulating the diseases and infections to which insects are susceptible. As mentioned in previous chapters, the hunter-and-prey relationship between certain kinds of insects can be used against the undesirable insects. Similarly, bacteria and viruses and other microscopic creatures can be used to attack particular insects. A number of tests are being conducted on various crop-destroying insects around the world. Such methods are safe for humans because insect diseases are highly specific to insects; they are completely different from diseases that affect people. Since 1888, about 100 species of insect predators and parasites have been introduced and established in the U. S. to combat unwanted (often accidentally imported) insects. Only California has a formal program in biological control of insects; unfortunately, such research does not receive the monetary support that continues to be lavished on chemical research programs. Forests offer an incredible opportunity to cooperate with nature in controlling unwanted insects. Canada and Europe have gone much further than the U. S. in developing real forest hygiene practices, especially the strong support of birds through nesting box programs and the like. In Germany and Italy, red ants have been used very successfully to protect reforested areas. Spiders are a huge part of the work of a pioneer in the field of natural forest protection, Dr. Heinz Ruppertshofen. Incredible insect control can be achieved by maintaining an adequate spider population. Canada has used small mammals for similar purposes. A single shrew can eat up to 800 sawfly cocoons in one day. Chapter 17 The Other Road 50 The key is to be imaginative, creative, and cooperative with natures inherent balances. The use of poisons has failed terribly and continues to fail despite ever-increasing efforts to find new and better poisons. We must stop trying to beat nature with the club of man-made poisons and learn to work within the intricate structure of the earth. If we do not, we will destroy the earth and ourselves. Chapter 17 The Other Road Analysis Carson ends her book with a strong, positive call to action. She provides a spark of hope by providing details about numerous efforts at natural insect control that in many cases have succeeded beyond expectation, even where chemical application has failed miserably. She emphasizes the miraculously interwoven relationships among the thousands of species on the planet and the hope that we humans can give up our arrogance and brutality before it is too late. In contrast with the nightmare-fairytale described in the first chapter, with its once upon a time tone that suddenly twists into a macabre reality, this chapter provides a hopeful but realistic possibility for the future if only we listen and demand change. Chapter 17 The Other Road 51 Key Figures The Chemical Industry Because Carson refrains from naming particular corporations, the pesticide makers assume the monolithic shape of an evil empire in Silent Spring. Yet Carson does not preach at the industry . Yes, it develops hundreds of new deadly toxins a year, and, through disinformation and pressure on government agencies, it promotes their widest possible use the book is very clear about these things. But Carson seems to view such activity as natural to the commercial enterprise and wastes no time calling on pesticide producers to reform themselves. The Government The government is the other great villain in Carsons story, and though one might think it is the chemical industry that bears primary responsibility for what has occurred, she is much more critical of public servants. Her thinking seems to be that more is to be expected of government. In succumbing to political pressure and helping pesticide makers promote their products, she argues, government has lost sight of its raison detre (reason for being), protecting the public interest. Carson holds that instead of echoing industry disinformation and spending taxpayers money on reckless pest eradication programs, agencies like the Department of Agriculture and the Food and Drug Administration ought to impose stricter controls on the development, sale, and use of dangerous chemicals and to fund more research. Nature An overview of key figures in Silent Spring that did not mention nature would be quite incomplete. In terms of the amount of attention that is devoted to them, plant and animals are the most important characters in the book, surpassing humans by a wide Key Figures 52 argin, who are the focus of just a few chapters. Still, despite the almost infinite variety of life forms that Carson mentions, there emerges a single image of nature that has a crucial function in Carsons case against pesticides: nature as a fabric of life in which all things are connected, from the smallest of soil microbes to human beings and other large mammals. If readers accept such a v iew, they must also agree with Carson that the sledgehammer-like approach of current pest control introducing large amounts of extremely toxic chemicals into the environment to eradicate a few species of insects is indefensible. What poisons one part of the fabric of life poisons the whole. The Public Along with wildlife, the public is a major concern in Silent Spring. The image the book projects of this collective entity is that of a victim of the chemical industry, betrayed by irresponsible public officials and exposed to toxic pesticides at every turn. As the terrible side effects of pesticides become clearer, the public begins to ask questions, demand answers, and insist on greater responsiveness from government agencies. The Visionaries The heroes of Silent Spring come from several walks of life: scientists laboring patiently in an often tedious and seriously underfunded area of research to determine the precise scope of the pesticide threat; birders and other amateur naturalists, whose careful observation of wildlife in the field yields essential information about the problem; activists driven by a deep concern for their communities and the natural environment to challenge industry and government to behave more responsibly; and philosophers, writers, and other thinkers who help citizens understand the cultural sources not just of the pesticide problem but of the whole range of trouble that modern civilization has stirred up with technology . What all of these individuals share is an uncommon power discernment. Simply recognizing the broad impact of pesticides on Nature 53 the environment and health is a significant achievement. What makes Carsons visionaries even more remarkable is their having probed this tricky problem with great precision in the face of widespread disinformation and obstruction. The Visionaries 54 Themes The Science of Pesticides One of the great insights of Silent Spring is its grasp of the pesticide problem as a compound one. On one hand, there are the intrinsic dangers of these chemicals: their capacity to disrupt basic biological processes, their persistence in the environment, and so forth. But Carson knew that the manner in which a dangerous substance is also crucial. To understand how compounds like DDT and malathion have come to threaten life on a global scale, one has to examine what has been done with them. Each of the major themes of Silent Spring belongs then to one of two lines of argument; the first concerns the raw toxicity of pesticides, the second the recklessness with which they have been employed. Along with atomic fallout, the synthetic pesticides that came into wide use after World War II are the most dangerous substances man has ever created. The heart of the problem, science has shown, is the pesticides unique capacity for disrupting critical biological processes like metabolism and cell division. Acute exposure can cause catastrophic systemic problems paralysis, immune deficiency, sterility, etc. and small doses repeated over time can lead to grave illnesses like cancer. Carson attributes this radically disruptive potential to the distinctive molecular structure of synthetic pesticides. Part carbon, they mimic the substances that are crucial to life (enzymes, hormones, etc. ) and so gain entrance to sensitive physiological systems. Once inside these vital systems, the elements to which the carbon is bound (chlorine and other deadly materials) wreak havoc on the organism. Two other properties that increase the hazard of pesticides are, first, the slow rate at which they break down and become less toxic, and, second, their tendency to accumulate in fat tissue. It is these characteristics that make even low-level exposure to pesticides so dangerous. A dose that is too small to cause immediate harm