The Minnesota Department of Agriculture threw out thousands of pounds of donated venison over the last decade at food pantries and shelters across the state. The reason? It was poisoned with lead.

Since 2008, when the state began putting all donated venison under X-rays, a little more than 7% of the meat has been contaminated by tiny shards of lead that break apart from the most common rifle bullets and shotgun slugs.

The shards are small enough that they'd leave no crunch or taste. But the splinters can be found almost 18 inches away from where the bullet hit — putting virtually all deer taken with lead ammunition at risk of contamination.

"It takes only a couple pictures when you look at those X-rays and realize the extent of the lead particles," said Nicole Neeser, director of the dairy and meat inspection division at the Department of Agriculture. "It's like a light bulb goes off and you think 'Oh, they really are there.' "

The amount of contaminated meat thrown away fluctuates from year to year. In the past 10 years, hunters have donated more than 2,500 deer to food banks, providing about 94,000 pounds of food. Lead was found in more than 6,700 pounds of the meat.

While no studies have been done on the venison kept by deer hunters, there is no reason to think the handling or harvesting practices would differ much from the venison that hunters donate, Neeser said.

The vast majority of the 195,000 deer taken by hunters each year are kept by the hunters and their families. If that same 7% of venison is tainted with lead, it would mean Minnesotans potentially eat about 500,000 pounds of lead-contaminated meat every year.

"We've used lead for so long in fishing and hunting it's like we lost our fear of it," said Carrol Henderson, who supervised the Department of Natural Resources' nongame wildlife program for more than 40 years before retiring in 2018.

It isn't clear what the exact risk is to hunters and their families. No amount of lead is considered safe, and exposure can cause neurological defects and lower intelligence, and it can harm kidneys, bones and nerves.

Human health concerns over lead-tainted venison were first raised in 2008, when a North Dakota physician used a radiograph to test 100 donated packages. He found lead in 60 of the packages. Since then, more studies have shown just how prevalent the metal is in game meat.

Lead rifle bullets and shotgun slugs are by far the most common types of ammunition used each fall by deer hunters.

In fall 2010, the DNR conducted a series of tests on sheep carcasses to see if any meat from a deer shot with a lead bullet was safe. They found the lead could splinter about a foot-and-a-half inside the animals, meaning shards of lead from a clean shot over a deer's front shoulder, near its heart, could reach the meat in nearly every part of the body.

"All meat from a deer harvested using a lead bullet has the potential to contain at least some lead," the DNR concluded.

Lead accumulates in the environment, and it can be difficult to trace where it came from when people are exposed to it.

In 2015, Quebec's Ministry of Forests, Wildlife and Parks tried to nail down the risk to people from lead ammunition. It found that nearly 3% of children who eat venison once a week from deer killed with lead would consume enough of the toxic metal to lower their intelligence. Nearly 2% of adults would eat enough lead to raise their blood pressure.

The way a deer is butchered can help reduce the risk of lead, especially by cutting away more of the meat near exit wounds. More lead was found in ground venison than in steak and whole cuts, Neeser said.

But the simplest way to avoid lead would be to switch to copper ammunition, Henderson said. Copper ammunition, which stays relatively intact after contact, is easily found online, even if it can be difficult to find on the shelves at some outfitters, he said.

"Over the past 10 years the technology for nontoxic ammunition has advanced light-years," Henderson said. "It's available and can be delivered right to your door, it performs as well or better than lead and the cost is equivalent."

Minnesota lawmakers are considering a handful of incentives, including sales tax exemptions for nontoxic ammunition and giving a voucher for free copper or nontoxic ammo to everyone who completes a firearms safety certificate.

Greg Stanley • 612-673-4882