Looks like the type of flight path that would be used to create the aerial photo maps that used to be available from Google and Bing before they replaced them with purely satellite imagery.
Edit: Just checked and found that Microsoft still provides their aerial photo maps.
https://uk.flightaware.com/live/flight/N980AE/history/20220717/0718Z/EGTK/EGTK
Looks like the type of flight path that would be used to create the aerial photo maps that used to be available from Google and Bing before they replaced them with purely satellite imagery.
Edit: Just checked and found that Microsoft still provides their aerial photo maps.
Crop dusting.
DDT, Mercury, Lead dust, Radon, aerosolized virus? No one can say.