There is no shortage of people who will do anything for money (duh,right). I knew an old timer, long dead from a rare cancer, who told me he was paid good money to dump (spread) toxic chemicals from industry on old farmland that wasn't being used around a mid-atlantic city in the late 40's,early1950's. Land owners would take the money and be lied to about what was being dumped and many times chemicals would be dumped on land with absentee owners.
As the city grew, suburbs sprouted up from the old farmland as it was developed.
What resulted was huge and concentrated clusters of cancer in particular neighborhoods. Studies were conducted and it became a huge story as journalists reported on them.
The old guy I worked with told me years before any of this broke, many of the locations he frequented late at night and they matched perfectly.
He said he was moonlighting and needed money to raise his family.