Final answer:
The 'strange blight' Rachel Carson discusses is the environmental damage caused by the overuse of pesticides like DDT, leading to bioaccumulation and ecological threats to wildlife.
Step-by-step explanation:
The "strange blight" that appears all over town, as mentioned in Rachel Carson's essay, refers to the environmental damage caused by the indiscriminate use of pesticides, such as DDT. In her book Silent Spring, Carson discusses the adverse effects of these chemicals on the environment, particularly on wildlife. The blight is the result of a bioaccumulation process, where the toxicity increases as it moves up the food chain, affecting birds and other animals.
Carson's essay warns about the long-term ecological dangers that arise from the overuse of chemical pesticides. Her work also highlights the misleading information provided by chemical companies regarding the safety of these substances. Her influential book contributed significantly to the environmental movement and led to increased scrutiny of pesticide use.