As the internet freaked out over Interior Secretary Ryan Zinke riding a horse to his first day on the new job Thursday, environmental activists expressed outrage over one of his first actions: overturning a federal ban on hunting with lead ammunition in national parks and wildlife refuges.

Zinke signed Secretarial Order 3346, which repeals a U.S. Fish and Wildlife Service directive the Obama administration issued the day before President Donald Trump took office barring the use of lead ammunition and fishing tackle in national parks and wildlife refuges. Zinke also signed an order to expand hunting, fishing and recreation access on federal lands.

“Outdoor recreation is about both our heritage and our economy,” Zinke said in a statement. “This package of secretarial orders will expand access for outdoor enthusiasts and also make sure the community’s voice is heard.”

Tami A Heilemann Interior Secretary Ryan Zinke signs an order to overturn a federal ban on hunting with lead ammunition.

The former Montana congressman said his new orders will allow people outside of the “land-owning elite” to participate in outdoor recreation on public lands. Pro-gun groups like the National Rifle Association claim lead-free bullets are more expensive and harder to obtain than their toxic counterparts.

But the Obama administration’s ban on lead ammunition was meant to protect wildlife from lead poisoning. As many as 20 million birds and other animals die of lead poisoning each year as a result of the nearly 100,000 tons of lead that hunters, fishers and other sportsmen use, according to the Center for Biological Diversity.

“There’s no good reason to be using toxic ammunition lead,” Jonathan Evans, CBD’s environmental health legal director, told The Huffington Post. “There are a range of substitutes on the market today.”

A 2012 study from the University of Guelph found the retail price for most calibers of lead bullets was comparable to their non-toxic counterparts.

The NRA, which pumped $30 million into Trump’s presidential campaign, strongly supported Zinke’s repeal of the lead ammunition ban. Despite mounting scientific evidence, the NRA claims there’s no proof that lead ammunition causes great harm to wildlife and humans.

“The fact is that traditional ammunition does not pose a significant population-level risk for wildlife,” Chris W. Cox, executive director of the NRA’s Institute for Legislative Action, said in a statement Thursday. “On behalf of the five million members of the NRA and tens of millions of American sportsmen, we thank Secretary Zinke for eliminating this arbitrary attack on our hunting heritage.”

Luis Sinco via Getty Images An L.A. Zoo condor keeper handles California condor No. 462 on Oct. 30, 2013. The female bird was being treated for lead poisoning. Zoo officials believe it was sickened after ingesting carrion contaminated by lead fragments from a hunter's ammunition.

“This is just another attempt by the extreme pro-gun lobby to limit common-sense controls that protect the environment and the public health from the dangers of guns,” Evans said. “There is really no good reason besides the NRA’s death grip on any kind of regulation associated with guns.”

National Wildlife Federation President and CEO Collin O’Mara, whose organization has supported non-toxic alternatives to lead fishing weights, stood alongside Cox and other representatives of sportsman groups as Zinke signed the orders.

“Having less lead in the water and soil is better for wildlife,” O’Mara told HuffPost. “But the best way to do this is not through a policy in the last few days of an administration but to have a science-based collaborative process with sportsmen and states that comes to a solution.”

O’Mara said examples for striking a balance between healthy wildlife and outdoor recreation could be found at the state level, citing some who have tried to “phase out” lead in favor of substitutes.

“I think most sportsmen want the same outcome, which is healthier wildlife, but the question is the best way to get there to make sure that the outdoor experience isn’t harmed in the short term,” O’Mara said.

Mel Melcon via Getty Images A female condor takes to the sky at the Hopper Mountain National Wildlife Refuge, north of Fillmore, Calif., after being released from a crate by a California Condor Recovery Program biologist. This rare condor nearly died of lead poisoning in 2013.

Lead poisoning from ammo is one of the biggest reasons California condors remain on the endangered species list, according to the conservation group The Peregrine Fund. In a move to protect its wildlife and environment, California has passed a bill to phase out all lead hunting ammunition by 2019. Bald eagles and other scavengers are also frequent victims of lead poisoning from ammunition, ingesting bullet fragments as they pick at carcasses.

Humans who consume animals killed with lead bullets are also at risk. A 2009 study from researchers at the University of North Dakota School of Medicine documented a health risk from lead exposure to humans who eat venison. The report found 59 of 100 randomly selected packages of ground venison donated to the Community Action Food Pantry in North Dakota in the fall of 2007 were contaminated with lead fragments.

Environmental advocates worry Zinke may target other measures meant to protect endangered animals. During his confirmation hearing, Zinke said he would consider rolling back Obama-era plans to halt oil and gas drilling in the Arctic, which environmental advocates say would threaten polar bears and other wildlife.

Wayne Pacelle, president and CEO of The Humane Society of the United States, said in a statement that the ban on lead ammo had the potential to be “one of the most effective policy decisions to protect wildlife.”

“The revoked order would have stopped the needless, incidental poisoning of wild animals by toxic lead ammunition and fishing tackle on more than 150 million acres managed by the U.S. Fish and Wildlife Service,” Pacelle said.

CORRECTION: In a previous version of this article, the National Wildlife Federation was misidentified.

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