Question

Chlorofluorocarbons (CFCs) are believed to be associated with cancers because,

• A. CFCs react with DNA and cause mutations.
• B. CFCs react with proteins involved in DNA repair.
• C. CFCs destroy the ozone layer and permit harmful UV rays to reach the earth.
• D. CFCs react with DNA polymerase and reduce fideliy of DNA replication.

Answer 1

The correct option is C CFCs destroy the ozone layer and permit harmful UV rays to reach the earth.

Chlorofluorocarbons released into the atmosphere have various ill-effects. These are used as coolants in refrigerators, coolers, etc. CFCs on reaching the atmosphere break the ozone molecule resulting in the formation of oxygen radical and $O_2$. This oxygen radical results in depletion of the ozone layer that leads to the penetration of the harmful UV radiations from the sun into the Earth's atmosphere. UV rays are responsible for cancer. Thus, the correct answer is option C.