Silent Spring

Carson articulates more clearly the impacts of humans’ long-term exposure to chemicals by demonstrating that there are numerous concerning health effects related to chemicals in the environment. This “never-ending stream of chemicals” (188) can cause delayed effects through absorption over a lifetime. Like nature, the human body contains complex relationships which means many of the impacts of these chemicals can remain relatively undetected for a long time.

The ways that chemicals are stored in the body can be part of the reason that the impacts can remain hidden. Insecticides which are fat-soluble “become stored in individual cells, where they are in position to interfere with the most vital and necessary functions of oxidation and energy production” (191). Other types of chemicals impact the nervous system, causing symptoms like “insomnia, nervous tension, and feelings of acute anxiety” (193), as well as tremors. In addition, because some chemicals interact with one another when they are in the same environment, it is almost impossible to predict how a human body will process the different chemicals it has been introduced to. 

In Chapter 13 Carson turns her focus to the inner workings of the human body. More specifically, she looks at the ways the “minute structures within […] cells” and “the ultimate reactions of molecules” (199) are affected by chemical exposure. Carson argues that the process of transforming matter into energy within cells can be stopped by certain types of common insecticides and pesticides. The “cycle of oxidation” can come to a “halt” (204) when enzymes are weakened. This is also related to diminished reproductive capacity within germ cells. These kinds of mutations and problems “may lead to disease in the individual […] or they may make their effects felt in future generations” (208). Carson closes the chapter with a strict warning that because chemical manufacturers do not have to test for the genetic effects of their compounds, there is little being done to “reduce this threat” (216).

Humans are responsible for the creation of a number of cancer-causing compounds, called carcinogens in the medical field. Against these “man had no protection, for even as his biological heritage has evolved slowly, so it adapts slowly to new conditions” (220). Humans took a long time to understand the ways that cancer is caused and impacts the body. Earlier in the 20th century, cancer was considered “a rarity” (221); at the time of Carson’s text, the “American Cancer Society estimate[d] that 45,000,000 Americans now living [would] eventually develop cancer” (221). Most of the chemicals used as insecticides or pesticides can be traced to cancer. Arsenic, DDT, and herbicides IPC and CIPC are all scientifically proven to be carcinogens, wreaking havoc on the human body.

Carson tracks how “a substance that is not a carcinogen in the ordinary sense may disturb the normal functioning of […] the body in such a way that malignancy results” (235). In particular, this seems to occur with cancers of the reproductive system which are linked to “disturbances of the balance of sex hormones” (235). In addition, there may be connections between “physical and […] chemical agent[s]” (238).

Throughout human history, science has brought infectious disease under control, yet humans have failed to stop cancer. In Carson’s opinion, this is because there needs to be a two-fold approach that addresses both therapeutic measures that cure the patient as well as “reducing the foci of infection” (241). Carson reminds the reader that “man has put the vast majority of carcinogens into the environment, and he can, if he wishes, eliminate many of them” (242).