The CHEM trail hypothesis holds that some trails left by aircraft are chemical or biological agents "deliberately sprayed" at high altitudes for purposes undisclosed to the general public in clandestine programs directed by various government officials. The term chemtrail is a combination of the words "chemical" and "trail," just as contrail is a contraction of "condensation trail." The term does not refer to other forms of aerial spraying such as agricultural spraying ('crop dusting'), skywriting, or aerial firefighting. The term refers to aerial trails allegedly caused by the systematic high-altitude release of chemical substances not found in ordinary contrails ... and that these trails are causing respiratory illnesses and other health problems.



