I posted a link somewhere on here to a debunking (or at least a claim of such) of the video that was posted. Apparently the testing done in that particular case were not aerial samples but samples from the bottom of a pond and the aluminum levels were consistent with what is found naturally occurring in your average dirt. I would be curious to see some studies that included samples taken directly from the trails. I don't think I have seen any but that doesn't mean they don't exist. As with all studies, the devil is in the details.

I just get frustrated when I see people post things comparing a tea kettle to a con trail (for example). It's arguments like those that give conspiracy theorists a bad name. Some people take to these theories as if it were a religion and based on what is often rather flimsy evidence. I'm willing to believe these trails are something nefarious but it's going to take more than a tea kettle comparison and a study of pond muck to convince me. Sure, I'm extremely skeptical of everything government says (though I don't recall them making much in the way of pronouncements about contrails) but I'm also skeptical about every conspiracy theory I hear unless there is something to substantiate them beyond conjecture, bad analogies and questionable correlations.