It's not even a matter of whether a particular substance is a "pollutant" or "toxic". Many necessary substances can be harmful if present in high concentrations. You can die just by drinking too much water. That doesn't mean that water's a pollutant, even though too much can kill you. The argument that carbon dioxide is not a pollutant because plants need it is similarly confused -- too much of a good thing can be harmful.
To get to the heart of the matter, the EPA considers any harmful emission to be a pollutant, even if the substance emitted is necessary for life.
A scientist, like any person, can say anything they want. You shouldn't believe something a scientist says just because they say it. They have opinions and can be wrong just like everyone can. I'm sure some scientists say ghosts exist and others say they don't.
Science, on the other hand, can find no evidence of ghosts. That doesn't mean they don't exist, however. Science makes no statement one way or the other on the subject of ghosts. They have never been observed, as far as we know, but could still exist.
Where do you get this "end of the world" thing? As for the claim of "alarmism", do you not remember the flu strain several years ago that tended to kill healthy people in the prime of their life, rather than "immunocompromised hosts"?
It's not that the reports are "alarmist". It's (1) you're not understanding the actual risk, and (2) you're pretending that the reports are predicting the end of the world.
The moon is made of green cheese. -- John Heywood