The mainstream media, which includes Wikipedia, the History Channel, Fox and "reality" TV as well as "legit" newscasts and stories, is profoundly flawed as a means for being informed as to what is really happening in the world. So you naturally supplement it with info from other sources and balance it out. I know a lot of folks in aviation, and none that I know regard chem trails as real. I attribute the criss-crossing patterns of contrails in the sky to military exercises and/or commercial traffic and weather conditions.
I do think that an only half-way well-meaning medical establishment plays a huge part in this and is encouraged by government to condition and terrify people into believing that they are constantly threatened by just about everything health-wise and must be monitored cradle to grave by "modern doctors" or else!!!
That's not even touching on the fear used to promote the environmental agenda where government needs to monitor/control food and energy consumption or the world will end.
Fear is a powerful tool. Michael Crichton titled his best book "State of Fear," and he nailed a societal trend -- of using fear to make people surrender to government oversight.