The book by Rachel Carson highlighted the ecological and health hazards of indiscriminate use of which pesticide, particularly in the mid-20th century?

• A. Glyphosate
• B. Malathion
• C. Chlorpyrifos
• D. DDT

Answer: (D)

The main idea this question tests is understanding the pesticide that Rachel Carson warned about in her book for its lasting ecological and health dangers when used without caution. In Silent Spring, Carson drew attention to DDT, a chlorinated pesticide used widely after World War II for farming and malaria control. DDT is highly persistent in the environment and tends to accumulate in the fat tissues of organisms. As it moves up the food chain, it becomes more concentrated, a process called bioaccumulation. This had dramatic ecological effects, most famously thinning the eggshells of birds such as raptors, which led to declines in their populations. The book also raised concerns about potential health risks to humans from long-term exposure.

This exposure of widespread harm helped fuel the modern environmental movement and led to policy changes, including regulatory action against DDT in many countries (such as the U.S. ban in 1972). Other pesticides, like glyphosate, malathion, or chlorpyrifos, have their own risks, but DDT is the pesticide Carson highlighted for its severe and lasting ecological and health impacts in the mid-20th century.