Most of the ones that I have taken have been off the playa lakes in West Texas. Some of the tanks were near old mines (copper, iron, salt). They've all been in the central flyway.

The puddle ducks from the same ponds and areas were fine. We have no way of knowing how long they'd been on the ponds/rivers, etc or even in the area. The geese have been fine too.

I stopped shooting divers all together as a result. Used to make my old dog so mad, "it's a duck, shoot it!"