If powerlines make you sick they're going to do so in an entirely different way than drinking polluted water would, which will make you sick in an entirely different way than using drugs.
What you said can be boiled down to "stuff makes you sick", and while you are correct, you've done nothing to rule out viral infections being among that stuff.
Terrain is about environmental influences such as living near power lines, pollution, or inhaling poppers as you let your boyfriend fuck you ass.
That's so broadly defined it becomes meaningless.
If powerlines make you sick they're going to do so in an entirely different way than drinking polluted water would, which will make you sick in an entirely different way than using drugs.
What you said can be boiled down to "stuff makes you sick", and while you are correct, you've done nothing to rule out viral infections being among that stuff.
Read "Inventing the AIDS Virus" by Dr. Peter Duesberg
Then get back to me.
You prove you believe this enough to inject yourself with HIV blood, and then I'll consider reading a book at your behest.
Until then I'm not taking a 15-hour homework assignment from a comment that took you 5 seconds to write.