I've seen far too many of his talks and interviews on youtube to recall which ones had him speaking about it himself, but here is his wife:
> "Tyrone was asked to be on a scientific panel to review the evidence about atrazine. When he discovered these results and reported it to them, they asked him to do some additional work to make sure that these things were really accurate. So he did some additional work and then they wanted him to do more and more and more and this is where Syngenta said basically we can fund you for a really long time if you'll just keep repeating this. It could have been very easy just to take all the money they were offering and be set for life. It would have been like an endowment for life for him, for research." (https://www.newyorker.com/video/watch/the-new-yorker-present...)