From this story in the Des Moines Register:
Iowa's new dove hunting law will result in toxic lead poisoning to animals and possibly humans, an environmental advocate on Wednesday told state officials who are reviewing rules to implement the law. Also at the meeting, an official from the Iowa Department of Natural Resources told lawmakers that toxicity from lead ammunition is a state concern that's being reviewed in light of the impending dove season, tentatively set for Sept. 1. Lead poisoning can cause damage to the nervous system, paralysis and eventually death. Studies have documented lead poisoning in scavenging animals such as eagles and condors that ingest spent lead from their prey, said Neila Seaman, Iowa director of the Sierra Club.
"No hunting of mourning doves should be allowed by the Iowa DNR until there's a statewide ban on the use of lead shots," Seaman told the Administrative Rules Review Committee._