The right answer is Scientists should conduct long-term studies of DNA technology to determine the consequences.
DDT is a potent insecticide: it kills by opening the sodium channels of insect neurons, destroying them instantly, leading to spasms and then death. Some genetic mutations acting on the sodium channels can make some insects resistant to DDT and other insecticides working on the same principle.
The US Environmental Protection Agency has categorized DDT into the B2 class, that is, potential carcinogen for humans. This supports the fact that the insecticide acts on human DNA.