Question

In 1972, DDT was banned from agricultural use in the United States. Environmental scientists proposed that the ban would be a solution to help increase populations of organisms such as the eagles. Which natural phenomena was the ban designed to reduce?

A. carrying capacity
B. succession
C. bioconcentration
D. biological magnification

Answer 1

The 1972 ban on DDT in the United States was primarily aimed at combating biological magnification, which was causing the thinning of eggshells of top predators like eagles, leading to population declines.

Step-by-step explanation:

In 1972, DDT was banned from agricultural use in the United States primarily to reduce biological magnification, which refers to the increasing concentration of persistent toxic substances such as DDT in organisms higher up in the food chain. DDT's persistence in the environment and tendency to biomagnify led to detrimental effects on top predators like eagles. The thinning of eggshells in bird populations due to DDT exposure was a significant problem, causing breakage during nesting and hindering reproduction, thereby threatening the survival of species like the bald eagle. The ban was designed to halt this damaging ecological impact and has indeed helped in the recovery of affected bird populations since then.