I think they might be synonym, but I'm just not sure.
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Please include the research you’ve done, or consider if your question suits our English Language Learners site better. Questions that can be answered using commonly-available references are off-topic." – Kris, tchrist
If you search in online dictionaries (for example, the word Pollute) you will find that they equate pollute and contaminate. Both words mean to introduce a foreign substance to something and to thereby make it unclean or impure, but they are used in different ways.
Pollute is usually used with environmental things such as rivers, streams, oceans, air, and is usually introduced as a chemical or particulate such as smoke or vehicle exhaust (see the usage examples, here, and also here, also this definition.) Light and sound can also pollute the environment, which is why astronomers seek remote regions for observation because there is little light pollution. If an atomic bomb explodes it introduces radioactive pollution to the environment. Cars pollute the air and factories pollute rivers and oceans. Pollute often has wide ranging implications and areas of influence. That said, one can pollute a conference room with cigarette smoke, and the room may only fit 12 people; not as far reaching as factory pollution but apt nonetheless because an environment is being dirtied with smoke (see here.)
Contaminate is used when a pathogen is introduced to a substance which needed to remain pure (see definition here and here.) Raw chicken can be contaminated with e-coli (again, see here). Dental instruments may be contaminated with viruses. A laboratory may have mixing vessels that become contaminated with a chemical. Toxins and poisons contaminate things. The environment does not need to be pure and can handle different levels of foreign substances and still be usable, so pollute is used for it. However, notice that in the Cambridge example quoted above, contaminate is used to talk about a coast. In this instance, the writer probably feels that the coast is pure. I would have used the word "pollute." So for environmental issues pollute and contaminate can often be used interchangeably.
Contaminate is a stronger word than pollute, so the idea that "rock and roll music lyrics pollute the minds of the youth," is, in my opinion, a better fit than contaminate, however this depends on the effect the speaker wishes. A religious believer may say that the internet is contaminating the minds of our youth, because for them the mind is something which is pure and is being dirtied by the internet. Relationships can become contaminated (see here,) as can group morale (see here,) and political parties (see here.)
To summarize, contaminate is used when a substance makes something which needed to remain pure, unclean. Pollute is used when the environment is made dirty but can still be used.