Question

Published in 1962, Rachel Carson's Silent Spring began a national debate that changed Americans' attitudes toward the environment. Carson, originally a marine biologist, had begun noticing the adverse effects of pesticides on various ecosystems. In her book, she documents the effects of DDT, a pesticide that was then popular for agricultural use. In the environment, Carson noted the collapse of food chains and the decline of bird, fish, and other animal populations; in humans, effects of DDT include a higher risk of cancer and other illnesses.
<1) The book's central claim-that widespread pesticide use was the cause of significant harm to human health and to the environment-was highly controversial.
Conservationists, taking the book's message to heart, succeeded in banning the use of DDT in the United States in 1972. Others, however, pushed back against Carson's claims.
Proponents of DDT usage pointed to the pesticide as a cost-effective means of controlling mosquito populations in parts of the world with high malaria rates. Still, Silent Spring ushered in an era of greater awareness, leading people to start thinking more carefully about the environmental impact of chemical products.
<) What is the meaning of adverse as used in the passage?
valuable
subtle
intended
harmful

Answer 1

harmful

Explanation: "Adverse effects" means negative or harmful effects on ecosystems.