DDT was a hazardous:
insecticide
disease
industrial waste
weed killer

The answer is insecticide!

Explanation:

DDT's insecticidal action was discovered by the Swiss chemist Paul Hermann Müller in 1939. DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochlorine. Originally developed as an insecticide, it became infamous for its environmental impacts.

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.