The impact of pesticides on human health and natural ecosystems is what Carson began to assemble data about. In employing chemical pesticides, Carson argued for much greater sensitivity and care to the environment. As a preferable alternative for pest control, Carson further urged natural biotic agents. As cancer and other ailments took their toll, Carson's health deteriorated while her mother died in 1958. In 1962 the book Silent Spring was published. However, it provoked a lot of criticism. Rachel Carson was born in 1907 and never married. Since Carson called into question the idea of science as progress, she evoked a huge backlash.