You paranoid chemtrail conspiratorialists are seeing normal sky spoor from a marked increase in commercial air traffic. There is no question that air traffic is up sharply throughout the world. But not all sightings are of normal contrails.
Normal contrails dissipate less than one minute after formation.
Commercial aircraft do not cross each other's flight paths in Xs and grid-patterns at the same altitude. Normal contrails come from the engines and wingtips of high-flying aircraft. They do not stream from the tails of airplanes equipped with wing-mounted engines. Chemtrails have also been observed streaming in thick white streams inboard of the wingtips but outboard of wing-mounted jet engines, where aerial tanker refueling probes are also deployed. Contrails do not make people sick.