Is common weed killer also killing oak trees?

[Blue Gardener]

A lot of this chemical is used here in Iowa. If it kills oak trees, what is it doing to us? This was in the Cedar Rapids Gazette.

LUXEMBURG IOWA — At White Pine Hollow State Preserve just north of here, the pale bones of ancient white oaks stand next to still-green cousins whose spring leaves have been shredded by a mysterious malady.
Here and at other Eastern Iowa sites, Department of Natural Resources foresters have collected circumstantial evidence strongly suggesting that a weed killer sprayed on cornfields is damaging, if not killing, oak trees.
‘‘We don’t have the smoking gun, but we have lots of evidence pointing to acetochlor,’’ a leading corn herbicide, as the cause of oak leaf tatters, said Paul Tauke, chief of the DNR Forestry Bureau.

http://216.17.87.60/ee/cedarrapidsgazette/defaultr.php?pSetup=cedarrapidsgazette_free&