Why are new pesticides better than the old DDT?

Answer 1

Unlike DDT and other chlorine-based insecticides, the newer chemicals

are not stored in fat tissue; they are soluble in water, Animals can remove

them from their bodies by breaking them down in their livers and

excreting them. They can also be broken down within the soil, These new

compounds operate like nerve gases, which act by preventing electrical

messages from travelling from the brain to the muscles that control

breathing or the limbs, This either kills the animal directly or makes it

vulnerable to predators.

Although somewhat safer than the older chemicals, the newer

insecticides are not without their problems. First, they break down quicldy

in the soil, and so must be applied to crops more often. Second, these new

chemicals are not selective. Because the nerve action of most larger

animals is very similar, these insecticides are capable of killing mammals,

birds, reptiles, amphibians, and fish. Unintended changes to the food web

are difficult to predict. Third, animals that have died or been weakened by

the toxin put any other animal that eats them at risk through

bioamplification. Large dosages of the toxin can still cause death.

Answer 2

Unlike DDT and other chlorine-based insecticides, the newer chemicals

are not stored in fat tissue; they are soluble in water, Animals can remove

them from their bodies by breaking them down in their livers and

excreting them. They can also be broken down within the soil, These new

compounds operate like nerve gases, which act by preventing electrical

messages from travelling from the brain to the muscles that control

breathing or the limbs, This either kills the animal directly or makes it

vulnerable to predators.

Although somewhat safer than the older chemicals, the newer

insecticides are not without their problems. First, they break down quicldy

in the soil, and so must be applied to crops more often. Second, these new

chemicals are not selective. Because the nerve action of most larger

animals is very similar, these insecticides are capable of killing mammals,

birds, reptiles, amphibians, and fish. Unintended changes to the food web

are difficult to predict. Third, animals that have died or been weakened by

the toxin put any other animal that eats them at risk through

bioamplification. Large dosages of the toxin can still cause death.

Answer 3

Unlike DDT and other chlorine-based insecticides, the newer chemicals

are not stored in fat tissue; they are soluble in water, Animals can remove

them from their bodies by breaking them down in their livers and

excreting them. They can also be broken down within the soil, These new

compounds operate like nerve gases, which act by preventing electrical

messages from travelling from the brain to the muscles that control

breathing or the limbs, This either kills the animal directly or makes it

vulnerable to predators.

Although somewhat safer than the older chemicals, the newer

insecticides are not without their problems. First, they break down quicldy

in the soil, and so must be applied to crops more often. Second, these new

chemicals are not selective. Because the nerve action of most larger

animals is very similar, these insecticides are capable of killing mammals,

birds, reptiles, amphibians, and fish. Unintended changes to the food web

are difficult to predict. Third, animals that have died or been weakened by

the toxin put any other animal that eats them at risk through

bioamplification. Large dosages of the toxin can still cause death.

Answer 4

DDT was banned as a pesticide because it had many affects on human life, to the environment and more .

Answer 5

Many organisms have gained resistance to pesticides.

Answer 6

The bioaccumulation is less than DDT an the degradation in the environment is faster.