Question

When polynuclear hydrocarbons enter the human body , they cause cancer but they do not affect $DNA$.
A. True
B. False

Answer 1

The polynuclear hydrocarbons are made up of only hydrogen and carbon atoms. The structure of polynuclear hydrocarbons have multiple benzene rings. They are very dangerous for human beings .

Complete step by step solution:
As we know that polynuclear hydrocarbons are made when benzene rings are fused together . According to studies it has been proved that polynuclear hydrocarbons are carcinogens. The meaning of carcinogens is that they can cause cancer. Whenever the polynuclear hydrocarbon enters the human body they undergo many biochemical reactions which results in affecting and damaging the $DNA$. And finally it causes cancer to the human body. Some of the examples of polynuclear hydrocarbons are anthracene , coronene , naphthalene, ovalene .
So from the above explanation it is clear to us that when polynuclear hydrocarbons enter the human body , they cause cancer and affect the $DNA$.

So, the correct answer of the given question is : option B. False.

Additional information:
Polynuclear hydrocarbons are environmental toxicants. These pollutants can enter the human body through consumption of cigarette smoke, automobile exhausts, drinking contaminated water and contaminated food. Polynuclear hydrocarbons are found naturally in coal, crude oil and gasoline. We should try to minimise the use of fossil fuels, because they release polynuclear hydrocarbons when burnt which are very dangerous for the environment.

Note:
Always remember that polynuclear hydrocarbons are carcinogens, they cause cancer to human bodies. When polynuclear hydrocarbons enter the human body , they undergo many biochemical reactions. They damage the cells of the human body and affect the $DNA$.