[ursus]

Your mention of the use of humans to help orient crop duster pilots in the application of various pesticides reminds me of the potential risks involved. Back in the '60's and '70's the work as a spotter" was greatly coveted because it allowed for relatively high pay for a few hours work, provided one could arrive on site at the wee hours before the wind started up and spraying was halted. Several of my high school cohorts were lucky to get such jobs but may have paid for it later on. Two such died in their early thirties from cancers that were attributed to this work. They carried umbrellas to shield them from the spray, to no apparent benefit.