AP Biology/Pd. 2
11/13/13
“Silent Springs” Test
Content Questions:
1. Carlson classifies modern insecticides into two groups of chemicals. The first group, represented by DDT, is known as the “chlorinated hydrocarbons” and the other group, represented by Malathion and parathion, consists of the organic phosphorus insecticides. Although both are organic, the organic phosphorous insecticides are more poisonous than the chlorinated hydrocarbons and have the ability to destroy enzymes.
2. When insecticides “are built on a basis of carbon atoms,” it is both ingenious and threatening because carbon atoms are the basic building blocks of the living world. They can be modified to become the chemistry of all life, but they can also be
…show more content…
Too much of the insecticides will allow acetylcholine to build up which would lead to convulsions and eventually death.
2. Research in the early 1960s proved that high levels of DDT found in predatory birds were the cause of the decrease in their populations. When the predatory birds came in contact with DDT, their reproduction was directly affected. As a result of DDT's presence in the predatory bird's body, the eggshells of these birds started to become slender. These eggshells become so thin that whenever the mother bird would lie on the egg waiting for it to hatch, the eggs would break. Thus, the predatory bird population had no means of increasing, since their reproduction was not successful. Biological magnification had a large role to play in the decrease of the predatory bird population. Spraying of DDT on vegetation led to contamination of the prey populations such as fish. These prey started building large concentrations of DDT within their bodies. As a result, the predatory birds also got contaminated, since they preyed upon contaminated animals.
3. With regards to the genetic makeup of target insect populations, heavy pesticide use can alter their DNA to the point where the insects develop a resistance to certain insecticides like malaria mosquitoes to DDT. These effects can be counterproductive to long-term insect control because one the
Dichlorodiphenyltrichloroethane, better known as DDT is a notorious organochlorine pesticide that is created by the reaction of chloral with chlorobenzene in combination with sulfuric acid(Britannica p.1). It was first used as an insecticide in 1939 by Hermann Muller in Switzerland. DDT works as an insecticideby acting on the nervous system to generate the same neural impulse over and over causing body tremors and eventually death. DDT is an extremely stable chemical compound containing C14H9Cl5 which leads to some significant resistance issues when used as a pesticide. The most problematic property of DDT is its high fat solubility and extremely low water solubility meaning that it has a tendency to stick around in the environment for longer than we want since it is readily taken up in the bodies of nearby mammals.
Throughout his essay, Suzuki supports his arguments with specific examples. To justify his reasoning, the author uses the case of DDT, otherwise known as dichlorodiphenyltrichloroethane. This chemical compound is used as an insecticide to eliminate the population of malaria-carrying mosquitoes, which it did effectively, and saved millions of lives. Unfortunately, due to unforeseen circumstances, complications arose, which led to an increase in chemicals and caused a domino effect of
While there are studies that indicate that DDT can cause health problems such as reduced male fertility, genital birth defects, breast cancer, diabetes, and endocrine disorders (World Wildlife Fund, 1999), many of these studies are weakened by factors such as their age or their biases, due to funding from pro-ban organizations such as the Environmental Protection Agency or the World Wildlife Fund, combined with the lack of conclusive support from more neutral research. Furthermore, one particular paper mentions that methodological errors undermine many studies on the health impacts of DDT (Beard, 2006), and asserts that “it is still too early” to assess DDT’s role in a number of diseases. Chris Curtis, a professor at the London School of Hygiene and Tropical Medicine, also stated that there is “no convincing evidence that DDT … has caused any harm to humans” (Cone, 2009).
DDT is a very controversial product… but why? DDT was a pesticide used in the 1950s and it was very effective at killing mosquitoes. This was good because mosquitoes carry a very deadly disease called malaria. But soon the government banned its use in the USA. It supposedly has been decreasing the populations of bald eagles. They think that it makes the eggshells thinner, so when the eagle it trying to keep the eggs warm it might break the eggs on accident. Many people are happy about this ban and others are not. Some researchers feel that evidence supports a ban on DDT while others feel that it is an over reaction to an environmental concern. DDT has been shown to help control the malaria parasite. Evidence supports the banning
DDT has been used since WW2 as an insecticide to control the outbreak of malaria and typhus among troops and civilians. This is because malaria is spread by mosquitos and DDT was considered to be a powerful in eliminating these populations, thus decreasing the infection rate for malaria. Since it was first discovered as an insecticide, worldwide it was used in very large amounts because nobody knew any better and it was considered to be revolutionary. It wasn’t until 1962, when biologist Rachel Carson first outlined the potential harm DDT has on the environment, believing it caused cancer in humans and harmed bird wildlife. This led to the United Stated ban of DDT use in 1972, and later, a worldwide ban under the Stockholm
To understand pesticides, we must look at the facts about them. According to the EPA, pesticides are chemicals specifically designed and sold to prevent, destroy, or repel pests from garden, greenhouses, fields, and orchards (Learn About Chemicals Around Your House). Charlotte Gerber’s article, How Do Pesticides Kill Bugs, explained that pesticides targets insects and kills them by attacking the nervous system and then when the muscles are over-stimulated, this will lead to paralysis and death. The effect of the organophosphates that cause that in pesticides was discovered in the 1930's during World War II. They were used in the creation of nerve gas, which was used in chemical warfare. When used in lethal dosages for humans, organophosphates cause extreme excitability, convulsions, paralysis and in most cases, death (Gerber). According to Effects of Pesticides on Human Health, The World Health Organization estimates that there are 3 million cases of pesticide poisoning each year and up to 220,000 deaths, primarily in developing countries (Lah and Glibert 2011). Children, and any other young and developing organisms, are particularly vulnerable to the harmful effects of pesticides. Even very low levels of exposure during development may have adverse health effects. Exposure can even lead to neurological health effects such as memory loss, loss of
The use of pesticides is an important decision that thousands of communities face each year. Nobody likes dealing with mosquitos and the diseases they bring so using chemicals and pesticides is an option but with other consequences. Mosquitos carry West Nile Virus that affects the city of Genericville every year with 50 cases projected this year in the city and two fatalities as well. On the other hand, the chemicals proposed for controlling the mosquito population has its own risks. The pesticide Malathion is also dangerous to people if they come in contact with it before it degrades. The potential for citizens of the city being exposed is almost a certainty
In the early 1940’s, a new technology emerged that was able to successfully combat crop-damaging and disease-carrying insects. A new age of synthetic chemical pesticides use arose. After their impressive success in fighting deadly insect-borne diseases during World War II, pesticides were used widely to combat insect pests for agriculture and public health. Few people challenged the benefits of the new scientific and technological products and many embraced pesticide use with enthusiasm. Despite its success, doubts about pesticide use began to appear a decade later in the 1950’s, when the government began a vigorous pesticide campaign across the country against insect pests. Scientists began reporting heavy losses of avian and
The banning of insecticide, a major pollutant and neurotoxin, has been up for debate for a significant period of time. However,
Carson clarifies that “the sprays, dust, and aerosols are now applied almost universally to farms, gardens, forests, and homes-nonselective chemicals that have the power to kill every insect, the “good” and the “bad”.” In contemporary world today many people use these mankind chemicals without understanding the effects of nature. For example, the reproduction of bees are dropping traumatically because of the pesticides effects on the insects. According to CNN “How Pesticides are killing the bees “Recent data published in science, Nature and other un journals show that bees are dying from some pesticides that are found in our food supply.” The damaged the chemicals are doing to the bees have worries many scientists. The New York Times wrote, pesticide linked to honeybee deaths, “a group of pesticide believed to contribute to mass deaths of honeybees.” Another example of the harmful chemicals affecting the good insects are by destroying favorable insects such as lady bugs and butterflies, which are another great alternative way to pollinate flower. These beneficial insects are very important for human wellbeing; therefore, we should minimize the use of
DDT and other chlorinated hydrocarbons are very fat soluble so when these chemicals are sprayed on plants and these plants get eaten by animal the chlorinated hydrocarbon gets in the animal's fat. Then that animal get eaten by another animal and now that has the chlorinated
McGinn argues DDT is no longer as effective, it harms the environment, and therefore we should focus on the alternative solutions. She explains the ecological damage caused by DDT because the pesticide bioaccumulates. This means the DDT is absorbed by predators when they digest an exposed prey, and the concentration increases as it gets higher in the food chain. These long-term exposes are then likely to lead to physiological abnormalities, which somehow negatively affect both ecological and human health (McGinn, 285). In addition to the toxicity, the pesticide has lead to a resistance. Malaria developed resistant strands and is not likely to disappear even if the use of DDT is halted for years. She explains if this toxin is reapplied
DDT can help get rid of a lot of insects even the ones that can cut off important resources to us.
CropLife America, a chemical association, argue, “chemicals like chlorpyrifos aren’t really so harmful” (Lappe). In addition, if there wasn’t any pesticides then how would there be control unwanted insects that spread other diseases. Pruitt, the Environmental Protection Agency
According to a recent study done by EPA, thirty-three percent Unites States household use toxic chemicals such as pesticides and of thirty commonly used pesticides, nineteen have studies pointing toward carcinogens, thirteen are linked with birth defects, twenty-one with reproductive effect, and fifteen with neurotoxicity, twenty-six with liver or kidney damage. Environmentalist Rachel Carson book Silent Spring discusses the lethality of pesticides, specifically parathion. Rachel Carson hopes to change American’s attitudes toward nature and pesticide use. In this influential passage, Rachel Carson discusses disastrous affect of parathion on nature in order to dissuade the further use of toxic chemicals. Carson begins the column by illustrating