Answer:
DDT was first introduced in the United States in the 1940s as a powerful pesticide that was widely used to control insect populations.
DDT use led to the decline of the bald eagle population in the United States in the mid-twentieth century.
Bald eagles are at the top of the food chain and consume large quantities of fish, which can accumulate DDT in their bodies over time.
The accumulation of DDT in bald eagles led to a condition known as eggshell thinning, which caused the eggs to crack before they could hatch, resulting in a decline in the bald eagle population.
The thinning of eggshells occurs because DDT causes the female bald eagles to produce eggs with thinner shells.
As a result, many bald eagle chicks did not survive, leading to a decline in the population.
In addition to bald eagles, other bird species were also affected by the use of DDT, leading to a decline in their populations as well.
In the 1960s, research conducted by Rachel Carson and others brought attention to the harmful effects of DDT on the environment and wildlife.
As a result of this research, the use of DDT was banned in the United States in 1972.
Since the ban of DDT, the bald eagle population has shown signs of recovery, but is still considered a threatened species in many parts of the country.