The initial study did show that some dead condors had elevated lead levels in their blood but did not establish that the levels were due to anything other than natural lead in the environment.
The study was done by the Peregrine Fund, the same organization that temporarily stopped hunter meat donations (and caused the destruction of a large quantity--around half a ton, IIRC--of donated meat) in at least one state. They claimed that the meat could be contaminated with lead from bullets. A later study revealed that the concerns about lead particles (and their effects) in donated meat were baseless.
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