<br /> Some people believe airplane contrails are toxic substances sprayed at high altitudes by government agencies.<br />According to Mother Nature Network, conspiracy theorists say normal jet airliner exhaust contrails quickly dissipate.<br />However, chemtrails — which are loaded with toxic heavy metals and heaven knows what else — linger for hours.<br />But scientists beg to differ. In a survey of 77 atmospheric scientists, 76 said they had no evidence of toxic chemtrails. <br />
