Why do they keep that secret? Is it to cover for their lack of satellites?
Is that shit aluminum? I hear on the net that monsanto has patents on aluminum resistant seeds and plants. Too much aluminum is dangerous is it not?
Firstly, it is almost certainly illegal; a good reason to keep something secret, yes?
Secondly, if your enemies think that your comms system is based around untouchable satellites 20,000+ miles away in space, rather than on a complex & far more vulnerable ground/airplane-based network, it gives you a considerable tactical/strategic advantage does it not?
As to the make-up of the trails, I believe there are at least three different types for differing altitudes & purposes. I am unsure of their exact ingredients, but they likely do not contain pure aluminium/barium & instead consist of some easily-available substance containing these elements in oxide form.
Various industrial waste-products are a strong possibility, especially coal-ash from power stations, which is easily-available & already in the form of a fine ash, thus requiring less processing. Ultimately, it's just fine particulate muck that helps reflect radio waves...
You are correct that aluminium is bad for your health; it causes symptoms similar to alzheimers, which is why the government will not be keen on letting you know they are dumping tons of it on your heads every day.
As for the Monsanto thing, whether this is another red herring or whether they are preparing for the day when areas become so soaked in these substances that such seeds will be needed I do not know. I am aware of their research but have not investigated it in any depth.
I hope that helps.