The Peregrine Fund, which conducted one of the studies involving the endangered California Condor, said the evidence suggests humans who eat game shot with lead ammunition might also be at risk.
Recently published research suggests even very low levels of lead exposure in children can cause learning disabilities and in adults may increase risk of Alzheimer's disease, stroke and heart attack, said Michael Fry, director of conservation advocacy at the American Bird Conservancy.
"The lead studies have once again shown us that we ignore the plight of birds at our own peril," said Fry. "Condors, eagles, ravens and other wildlife have given us advanced warning of a problem that we are now learning may also have human health consequences."
The Peregrine Fund will sponsor a conference -- "Ingestion of Spent Lead Ammunition: Implications for Wildlife and Humans" -- May 12-15 at Boise State University in Idaho to explore the problem.