The "study" used to justify the California lead ban was a fabrication. An environmental activist from UC Santa Cruz used a technique to characterize the lead isotope ratios and claimed the condors were being poisoned by bullet lead. That technique was used by FBI for a time. It was found to be an invalid technique. FBI caused a lot of problems in the criminal justice system because of that. So, the woman from UCSC was questioned after the revelations about spurious techniques. She claimed her data was all destroyed an could not be examined. The lead ban stands. Now you know how it works in California.
All of the above is 100% factual.