The author begins by describing e perfect American town, with beautiful vegetation and countless varieties of plants and fruits. Suddenly, from the sky, comes a white fine powder and in days everything begins to die: plants, bees, the young animals and even the rivers are poisoned.
Mankind has developed in recent years the possibility and power to alter the environment by using chemicals and technological advancements. This however was not always in man’s favor as the longtime affects pesticides and other chemicals have on nature is not yet fully understood. Until modern times, nature and the environment had enough time to adapt to the appearance of new threats but because mankind produced them at such an alarming rate, nature did not had the chance to adapt.
Thousands of new chemicals are produced each year and while they are specifically designed to kill one animal or insect species, they affect other animals as well. The government and farmers tend to overdramatize the problems they have with pests and so more harmful pesticides are sold every year. What is even worse, the pesticides even failed to kill the pests they were intended to kill in the beginning. The lack of diversity when farming can also produce problems of its own as it makes the crop more vulnerable to disease and pests.
Another problem is that new species of insects and animals were introduced accidentally in environments they were not indigenous to. Because they had no natural predators in the new environment, the animal and insect species thrived and caused even more damage.
Humankind began developing more and more pesticides after the end of the Second World War and starting from that point, every living organism was exposed to pesticides in some way or another. Arsenic is considered as being one of the oldest pesticides used from the Renaissance time. Arsenic however is nothing but harmless and it was proved to be a carcinogenic.
In modern times, one of the most used pesticide was DDT, a substance considered as being safe when in powder form. The human body however stores the DDT in its fat cells and then over time it releases it, poisoning the body. The substance is easy transmitted and it can pass from plants to animals and to humans in a short period of time. It was also proved that mothers can pass on DDT to their children while in womb or through breast milk.
The pesticides that are spread aerially are even more dangerous and many people who were involved in spraying the chemicals ended up dying after being exposed to the harmful substances. Endrin is another substance used and many children and household pets died after they came into contact with surfaces treated with Enderin by the adults in the house.
Unwanted results occur when a person is exposed to two different chemicals and in time the said chemicals react violently in the carrier’s body. This can cause serious side effects impossible to control and that often result in tragic accident.
But pesticides are not the only substances that are dangerous and herbicides are mentioned as well. In some countries, they are banned completely but in the US, farmers are free to use them as they see fit.
Another problem is that rivers and other bodies of water became infected as well and chemicals have been found in the water even after a period of eight years after the area stopped being treated chemically. Species of birds disappeared completely from certain areas because they ate infected fish and then over time they died. What is even worst, the substances then were passed on to humans who also became infected by the chemicals in the water.
The soil and other organisms in the soil that have the purpose of breaking down biological and vegetal matter into nutrients have also been affected. The chemicals used can have the opposite effect from what the farmers expected and in some cases the species affected were not the ones considered as being pests but the species that preyed on the pests and helped control them.
Farmers use a limited number of domesticated plants and those they see as being useless they try to eliminate. The author mentions the sagebrush from the West and how farmers tried to eradicate it. What the farmers didn’t realized is that certain animals and birds used the sagebrush for food and shelter and when areas have been cleaned from sagebrush, those animal species disappeared. In the use of herbicides, other plants are destroyed in the process and it can even affect livestock that consume those plants.
Carson argues that a better alternative would be importing from other countries natural predators to control the invasive species. This would mean less pollution and less harmful chemicals to affect the plants and animals used by humans.
In 1959, the Midwest was sprayed with aldrin to try to combat a pest problem but the quantity used was so enormous that the pesticide accumulated on roofs as if it was snowing. Soon after, pets began dying, birds virtually disappeared from the area and humans began showing signs of pesticide poisoning. Despite this, the pesticide was sprayed again and this resulted in massive wildlife loses. Ironically, in other parts of the country, where pesticides were not used, the Japanese beetles were eradicated much faster and with less damage than in the Midwest.
The robins were the most affected bird species in some areas and almost 90% of the robin population died during the time when DDT was used as a pesticide. The eagle was also in danger and the number of eagles dropped drastically. The reason why the birds were affected was because their reproductive system was attacked and they no longer reproduced.
The salmon and trout in the rivers have also been affected because substances like DDT killed the larvae and other organism the fish fed on. This happened in Canada in 1954, Maine in 1955, British Columbia, Alabama, the Philippines, Colorado River in 1961 and the Indian River in 1955. In some of the rivers, some species of fish disappeared completely and the contaminated fish reached the seas where they contaminated other large fish such as sharks. The reason why the fish were the most affected is because in some way or another, every chemical may one day reach a water supply and then be carried into rivers, streams and other bodies of water. Fish are known to be weaker than other animals and they do not have the same resistance mammals have when it comes to synthetic chemicals. Because of this, some species of fish have been eradicated completely in certain parts of the world because the fish population was affected by pesticides and herbicides.
Some pests appeared in certain areas because they have been introduced accidentally by foreign visitors or when new crops not native to a certain area were introduced. This was the case for the gypsy moth and fire ant that appeared in America at the end of the 1860s. The government tried to eradicate the pests by using DDT but were unsuccessful and cows were instead affected in the process.
Chemicals are sold in every shop and so it is hard to determine just how bad the general public was exposed to chemicals. There is no clear way to determine a safe quantity of chemicals in the population’s everyday food and the state has no way of controlling the amount of pesticides and herbicides that end up in the fields every year.
If 100 years ago society was concerned with how smallpox and other disease affected the population, nowadays, the biggest threat is represented by the unregulated use of pesticides and herbicides. The fact that humans are exposed to more than one chemical makes the situation even worst because it is hard to determine how two chemicals with react with one another.
The pesticides are known to affect the nervous system, liver and the system that produces energy in the human body by disrupting the oxidation process. The chemicals in the human body may also cause mutations which can be dangerous for an unborn child, mutations that would appear naturally only about once in a couple of hundred years.
It is also suggested that maybe the rise in the use of pesticides and herbicides is what causes the rapidly growing cases of cancer. Nowadays, cancer is not something found only in adults but in children as well. What used to be 50 years ago a disease associated with certain professions, now became something inevitable. Leukemia became most associated with pesticide exposure but Carson tries to remain positive and suggest that just as we introduced these elements into our life, we can also eliminate them. Carson ends her book by concluding that nature is more than capable of regulating the animal population and all we have to do is let nature take its course.