"Advertisements are the most prevalent and toxic of the mental pollutants". In the passage, "Hype", excerpted from Kalle Lasn, the author talks about how much of a mental pollutant advertisements are. The main idea is in the very first sentence of this passage. "Advertisements are the most prevalent and toxic of the mental pollutants". The idea of this sentence is to make us fully aware about how advertisements work and how they effect everyone.
    The image that we get just by reading the first line of the passage has the most significant idea of the entire passage. As we read on we can  tell what the writer actually means by this single statement. as being the "most prevalent" of mental pollutants, the author is telling us of how there is almost no escape from mental pollutants. They do, in fact, feel as if though a part of our lives. Where ever we may look we will almost always see a logo, slogan or anything of the sort, that will be conveyed to us as an advertisement.
    I agree with the author in this case as even now all around me are logo's and pictures that represent different companies and different brands. Of course these advertisements might be considered mandatory for the sale of different kinds of products, but by the mass numbers we receive all of them in one day is too much for us. so much as that it can be also considered a minor form of hypnotism.