Amendment 83 May Block Effort to Restrict Lead Ammunition — Resulting in More Poisoning of Wildlife and People

Wildlife biologists, veterinarians, and toxicologists say 83’s language providing a constitutional right to “traditional methods” of hunting could shut down a pending petition asking CPW to phase out lead ammunition.

DENVER — Medical doctors, veterinarians, wildlife biologists, and leading wildlife managers expressed opposition to Amendment 83 because it would stymie a petition to Colorado Parks and Wildlife (CPW) to phase out the use of toxic lead ammunition in sport hunting.

Dan Ashe, a lifelong hunter and former director of the U.S. Fish and Wildlife Service, says that “there is no credible scientific or economic debate about the use of lead ammunition. It’s a threat to people who consume wild-game meat and to dozens of Colorado wildlife species that scavenge the remains of hunter-killed or wounded game, including eagles, hawks, and owls.” When the lead petition to CPW was filed in June, Ashe said it “lays out a crystal-clear legal and scientific case for regulatory action in Colorado.”

The petition, filed by Animal Wellness Action, the Center for a Humane Economy, Colorado Audubon chapters, and a dozen other organizations, asks CPW to begin rulemaking on a graduated phaseout of lead-based ammunition in favor of copper, steel, bismuth, and other nontoxic elements and alloys for hunting. That effort and other science-based reforms are now under threat from Amendment 83, which is backed by out-of-state trophy hunting interests, including Safari Club International.

Amendment 83 would add a right to hunt “by traditional methods” to the state constitution and make hunting and trapping the “preferred means” of managing wildlife, and that same sweeping and vague language could be used to bring back steel-jawed leghold traps, bear baiting, and wildlife-killing contests in Colorado.

Michael J. Kosnett, M.D., M.P.H., medical toxicologist and associate adjunct professor of environmental and occupational health at the Colorado School of Public Health, has devoted much of his career to preventing and managing lead poisoning. In 2013, he joined 14 other scientists in an Environmental Health Perspectives editorial calling for restrictions on lead ammunition. That editorial emphasized “the indisputable fact that no level of lead exposure in children is known to be without adverse health effects,” he wrote in his October 9 letter. “Lead ingestion may also contribute to adverse reproductive outcomes in pregnant women and cardiovascular disease in adults.”

Kosnett points out that hunting continues where lead ammunition has been restricted. “The right to hunt continues to exist in California, provided that hunting is conducted without lead ammunition. In October 2026, the European Commission also adopted restrictions on the use of lead-containing gunshot for hunting. Colorado could take similar action,” he wrote. “If Amendment 83 passes, however, enacting this commonsense health protection in Colorado could become more difficult.”

“The science on lead poisoning is indisputable,” said Marc Bekoff, Ph.D., professor emeritus of ecology and evolutionary biology at the University of Colorado Boulder. “Lead bullets and shot fragment on impact, scattering tiny particles through carcasses and gut piles left in the field. Eagles, ravens, and other scavengers who feed on those remains are poisoned and often die slowly and painfully.” Bekoff notes that the same fragments end up in game meat eaten by hunters, their families, and people who receive donated game meat through food banks.

“Even X-raying of meat does not adequately protect consumers from ingesting significant quantities of lead,” adds Mark A. Pokras, D.V.M., associate professor emeritus at the Cummings School of Veterinary Medicine at Tufts University and former director of the Tufts Wildlife Clinic, in his October 7 letter.

“[Amendment 83] could effectively place the use of lead ammunition beyond the reach of ordinary policymaking, treating it as a constitutional right and stifling any discussion of the issue at CPW before it can even begin,” wrote Pokras. Pokras and his students have performed necropsies on thousands of wild birds since 1987.

“We know that the backers of the constitutional amendment will challenge lead ammunition restrictions even though the science is settled on the issue,” said Wayne Pacelle, president of Animal Wellness Action and the Center for a Humane Economy. “Safari Club International, the Colorado Trappers and Predator Hunters Association, and the other extremist trophy-hunting interests that formulated 83 are dead set against limiting lead use despite hundreds of studies showing its detrimental effects on wildlife and people.”

California offers proof that phasing out lead works. Donald Smith, Ph.D., distinguished professor emeritus of microbiology and environmental toxicology, and Myra Finkelstein, Ph.D., adjunct professor of microbiology and environmental toxicology, both at the University of California, Santa Cruz, conducted research that helped support the state’s lead ammunition laws. Finkelstein’s recent study in Nature Communications found those laws reduced lead poisoning risk for California condors. “The scientific evidence that lead harms both wildlife and human health is beyond dispute,” Smith and Finkelstein wrote in their October 6 letter.

Daniel Doak, Ph.D., professor in the Department of Environmental Studies at the University of Colorado Boulder, is a co-author of that condor study. “As an ecologist and conservation biologist with extensive work on the effects of lead on one particular species, the California condor, I have seen the extent to which lead ammunition use can imperil native species,” he wrote in his October 11 letter. “Most broadly, this amendment would remove the ability of state managers to use improving information and understanding of wildlife science to best manage our public resources.”

Based in Durango, Elaine F. Leslie, Ph.D., a wildlife biologist for nearly 50 years and retired chief of biological resources for the U.S. National Park Service, worked on the restoration of the California condor at Grand Canyon National Park. “We celebrated the first wild-laid eggs and the first wild-hatched chick in over 100 years. But then we also watched in dismay birds we knew by their identification numbers sicken and die after feeding on gut piles and carcasses left in the field with lead bullet fragments dispersed throughout the carcasses,” she wrote in her October 12 letter.

Amendment 83 is opposed not only by leading scientists and animal advocates but also by responsible hunters and anglers, including Colorado Hunters and Anglers for Sensible Wildlife Conservation. Because it would amend the state constitution, Amendment 83 needs to clear a 55%  threshold of votes cast on the measure to pass. Animal Wellness Action and the Center for a Humane Economy are urging Coloradans to vote NO on Amendment 83 on or before November 3.