Silent Springs pt. 3

What is the title of chapter 13 referring to?

"Through a narrow window"

If we narrow our focus, we can see the effects of pesticides on the workings of individual cells.

- From the macro scale of entire ecosystems, Carson has narrowed her focus first to the human body and now to the functioning of individual cells.

What are some of the ways that pesticides might disrupt the vital functioning of this organelle's function, and why might it be so detrimental?

- The energy produced at each stage of oxidation within the Mitochondria is called ATP. ATP furnishes energy by transferring one of its phosphate groups to other substances. Once it has given up one of its phosphate groups, it is a diphosphate molecule, ADP. Then, in the next stage, another phosphate group is coupled on and the ATP is restored. ATP is found in all living organisms. The process in which ADP and a free phosphate group are combined to make a new ATP is coupled to the oxidative process. If the combination doesn't happen or becomes uncoupled, there is lost energy. Respiration continues, but it produces nothing.

- Uncoupling is only one of the things that can go wrong. Enzymes can be destroyed, thereby bringing the process of oxidation of cells to a halt. Many chemical poisons destroy enzymes

Why does Carson suggest carcinogens may be more dangerous to children than to adults? Does she offer any evidence to support this claim?

Suggested that congenital cancers and cancers in infants may be related to the action of cancer-producing agents to which the mother has been exposed during pregnancy and which penetrate the placenta tp act on the rapidly developing fetal tissues

Experiments show that the younger the animal is when it is subjected to a cancer-producing agent the more certain is the production of cancer

Carson discusses the "sea of carcinogens" which Americans are exposed to from the time of birth. What relationship does Carson see between outbreaks of cancer in wildlife and potential outbreaks in humans?

Dr. Hueper believes that our situation with regard to cancer today is very similar to that which faced mankind with regard to infectious diseases in the closing years of the 19th century. The causative relation between pathogenic organisms and many diseases had been established through the briliant work of Pasteur and Koch. Becoming aware that the human enviornment was inhabited by an enormous number of microorganisms capable of causing disease, just as today carcinogens pervade our surroundings

What is Carson's opinion about "the balance of nature"? What two critical factors have been ignored in the design of modern pest control programs?

Chemical control proponents overlook two important facts of nature: one, nature applies the most effective control of insects, and two, insects have an explosive capacity to reproduce once they have adapted to chemical control methods.

In the closing pages of the chapter, Carson provides an analysis of why so few entomologists were researching the possibilities of biological control. Why the neglect of this option?

Entomologists focus on chemical control of insect pests and consequently ignore biological control. Entomological research is suspect because it is heavily funded by chemical companies and the perpetuation of chemical methods.

1.What do you think is the significance of this chapter's title?
"Rumblings of an Avalanche"
2. What does Carson mean by the "Age of Resistance"?

that the destruction thus far, resulting from humanity's efforts to control nature, may be simply the "rumblings of an avalanche", that the consequences to trying to control nature are imminent as these organisms are becoming more and more resistant. → "within a matter of a very few years an ugly and dangerous problem had clearly defined itself"

Carson means that the "Age of Resistance" is when the insects, animals, and plants are becoming immun/resistant to pesticides.

How quickly did insects develop resistance to the new insecticides developed after WWII?

In the United States, DDT resistance among flies had become wides[read in the Tennessee Valley by 1948. Other areas followed. Attempts to restore control was met with little success, for in some places the flies developed strong resistance to this chemical within only 2 months

What about the possibility of human resistance to the new pesticides?

Although, theoretically humans could become resistant to chemcials by having the traits passed on through generations, human populations reproduce at the rate of roughly 3 generations per century, but new insect generations arise in a matter of days or weeks, so humans cannot become resistance to new pesticides.

Much criticism (even today) centers on the need to eradicate disease-carrying insects that cause untold human deaths. How might you use information in Chapters 15 and 16 to respond to these criticisms?

If we try to eradicate the disease carrying insects, they will build a resistance, nature fights back against the controls we try to put onto it, and the "rumblings of the avalanche" will grow louder because these disease carrying insects will be resilant. spraying only strengthens pests

An example, trying to eliminate malaria, in 1956 there were ony 5 species of those mosquitoes that displayed resistance, by early 1960 the number had risen from 5 to 28

According to Carson, what are the two major pest management options? What are the alternatives to intensive pesticide use? What is the general term for these alternatives, and what do they have in common?

The first, chemical poisons, has proven already to be costly, ineffective, and extremely, lastingly dangerous.

The second, biological controls, has proven already to be cheap, effective, and safe for humans and non-pest animals and insects. The use of biological controls works with the rules of nature instead of against them. It leaves intact the natural predators of the targeted insect and doesn't harm the rest of the environment of the targeted insect.

Describe how the screwworm control program in Florida succeeded. What other types of control systems that rely on the biological properties of insects does Carson discuss?

Dr. Edward Knipling has developed a 'male sterilization' technique, in which sterilized males of a species are released and gradually outcompete wild males until only infertile eggs are produced. He conducted a successful proof of concept on the island of Curacao, eliminating the native screw-worm population after releasing thousands of sterilized males from a plane. The program was then replicated on a huge scale in the Southeast, with great results.

There have also been experiments with synthesized hormones and defensive secretions that would be more targeted than general pesticides. Synthetic sex attractant for gypsy moths, for instance, is being deployed to disorient males during mating. some researchers are working with ultrasound waves, while others have developed disease vectors that are meant to be extremely species specific confidently asserts that these microbial insecticides are harmless to all but their intended targets.

there is the option of biotic control involving imported predators or parasites.

According to E.O. Wilson, what are some of the effects that Silent Spring's publication had on him personally,as well as on the larger public, and even on "nature"?

1. E.O. Wilson was a naturalist trained in field biology, and was working with chemists to break the code of pheromones used by ants to recognize their colonies. He saw what Carson had wrote in action, witnessing the fire ant eradication program, causing catastrophic environmental results, and the ants bounded back after to continue their spread. He became more of an enviornmental activist.

2. For the most part, Americans listened and began to turn away from wholesale toxic pollution

3. The book's message was blended with other scientific and literary efforts into the growing activist movement

4. Largely responsible for the establishment of the Enviornmental Protection Agency in 1970

5. Its most dramatic successes include the recovery of the American alligator, gray whale, bald eagle, peregrine falcon, and eastern population of the brown pelican. All were imperiled years ago, and all are now considered relatively safe