(CN) - Activists have renewed their campaign against lead bullets, which cause lead poisoning in scavenger birds like the endangered California condor, despite warnings that confrontation may spook hunters away from voluntarily giving up lead.
The Center for Biological Diversity and other opponents of lead-based bullets want the Environmental Protection Agency to regulate ammunition under the Toxic Substances Control Act.
Though the EPA denied a petition to enact such regulation last year, and a Washington federal judge dismissed the ensuing lawsuit, more than 100 groups and scientists filed a new petition in March.
"The widespread poisoning of many species of wildlife requires a response from the EPA to regulate lead ammunition," the filing states. "This petition presents strong evidence that lead shot and bullets pose an unreasonable risk to health and the environment and that this risk cannot be prevented through action under other federal laws."
The groups argue that the EPA does have the authority to regulate ammunition, which could include a "nationwide ban on the use of bullets and shot containing lead."
Though the groups want a nationwide ban on lead-based bullets, with exceptions for military and law enforcement, they say the government has plenty of options.
Both sides have identified preventable lead poisoning animals as the cause of massive fatalities among animals that feed on carcasses and gut piles filled with lead fragments after hunters leave them behind. But some wildlife officials and anti-lead advocates remain deeply ambivalent about a nationwide ban.
"More than 130 species of wildlife are affected by lead from these sources, and in some species thousands or tens of thousands of individuals die from lead ingestion every year in North America," according to the petition. "For most species there has been no assessment of the effect of lead-caused mortality on population levels. However, population level effects have been shown in well-studied species such as the California condor, bald eagle, trumpeter swan, sandhill crane and spectacled eider."
The problem is particularly acute on Arizona's vast Kaibab Plateau, north of the Grand Canyon, where the California condor rebounded from the brink of extinction and would be thriving but for the lead problem.
North America's largest flying land bird, the California condor can live up to 70 years under ideal conditions. Along with raptors such as the golden and bald eagle, the scavenging condor has been at the center of the lead-bullet issue for years.
"Since 2011, nearly half of the roughly 130 condors released since 1996 along the Arizona-Utah border have died or vanished, with lead poisoning being the leading cause of death," according to the petition.
Some parts of California have banned the use of lead bullets over concern for the condor, but hunter and anti-lead advocate Anthony Prieto said the ban has logged mixed results.
Prieto has been trying for years to convince his fellow hunters to switch to copper bullets, which don't fragment as much as lead bullets do, or to bury or pack out the "gut pile" removed from a kill in the field. Prieto calls a nationwide ban on lead ammunition a "drastic measure."
Despite the ongoing ban in California's condor habitat, "birds are still getting lead because not everybody follows the law," he told Courthouse News in an interview.