In Silent Spring, Carson gives a detailed explanation of how human cells function, according to the latest, state-of-the-art research of the late 1950s. In short, she says cells rely on oxidation to stay healthy. The process that allows cells to be properly oxidized is disrupted by the introduction of pesticides such as DDT. This disruption can lead to cancer and abnormalities in embryos, leading to birth defects.

We might quibble with some of her scientific details today, but the general point that pesticides can infiltrate a living organism in ways that cause cancer or birth defects is accepted and commonplace science now. At the time Carson wrote her book, however, this was new and startling research. People were largely unaware of the side effects of chemicals that were considered almost wholly beneficial. Her information helped galvanize the public to demand that certain chemicals, such as DDT, be banned and others regulated.