Lead fragments reach well past a two-inch trim

STEP 1 · Wound channel

Film counts outrun a two-inch trim

In July 2008 the Minnesota Department of Natural Resources shot 72 euthanized domestic sheep broadside through the chest from 50 meters (about 54 yards) at Carlos Avery Wildlife Management Area as whitetail stand-ins. A .308 provided five 150-grain designs. A 12-gauge provided a 1-ounce slug. A .50 muzzleloader provided two lead bullets. Eight whitetails killed in April 2008 with one rapid-expansion rifle bullet were included at an average near 110 m with a range of 80 to 175 m. The Minnesota DNR summary and Grund and colleagues' 2010 paper both report that test.

On the agency page ballistic tips averaged 141 fragments and the farthest fragment averaged 11 inches off the wound channel. One carcass carried a fragment 14 inches off the exit. Soft points averaged 86 fragments and an 11-inch farthest average. An exposed-lead bonded bullet sold for controlled expansion averaged 82 fragments and a 9-inch farthest average. Slug averages were 28 fragments and 5 inches at the farthest. The 245-grain muzzleloader average was 3 fragments and 1 inch at the farthest. The 300-grain muzzleloader average was 34 fragments and 6 inches at the farthest. Counted fragments in the 2 inches beside the exit came to only about 30 percent. On the agency page, lead in low amounts was reported out to 18 inches away from the exit hole.

Grund and colleagues assayed muscle at 5 cm and at 25 cm and at 45 cm from the exit. The 45 cm site comes to about 17.7 inches. Rapid-expansion bullets and one controlled-expansion design produced lead in muscle more often. No lead appeared in muscle from copper or from the enclosed-lead bullet. Near-exit slug samples contained lead in 40 percent of cases and no lead showed at 25 cm or at 45 cm. The count of fragments used no magnifying aid.

Hunt and colleagues in PLOS ONE radiographed 30 eviscerated whitetails that hunters killed in Sheridan County in Wyoming during November 2007 and every carcass showed metal. Results put the median at 136 fragments spanning 15 to 409. Outermost clusters sat 24 cm apart on average or about 9.4 inches. Cluster gaps ran from 5 cm to 43 cm and the biggest hit 45 cm or about 17.7 inches. The 24 cm number is the separation recorded on one flat film, and Minnesota measured outward from the channel or from the exit. Both still show metal beyond the bloodshot meat a hunter usually cuts away.

STEP 2 · Ground meat

Wyoming burger still carried metal fragments

A single 7 mm magnum load of 150-grain copper-jacketed lead-core bullets killed those Wyoming deer. Reported shots averaged 116 m and ranged from 25 m to 172 m. The thorax was hit on 26 of the 30 deer (87 percent) and bullet metal left the carcass on 92 percent of shots. All 30 carcasses were taken to separate commercial processors across 22 Wyoming towns, and the shops made regular steaks along with ground meat packed in 2-pound packages.

Ground meat still held metal for 24 of the 30 deer (80 percent). At least one fragment was seen in 74 of the 234 ground packages (32 percent). Correlation of carcass and package fragment counts was 0.06 so many fragments on a carcass did not mark dirty packages.

Of fragments cut from packages of 13 deer 25 of 27 were confirmed lead (93 percent). Package lead averaged 17.2 mg and ran from 0.2 mg to 168 mg. On those 13 deer shank meat taken far off the bullet path tested under the 2.0 µg/g detection limit. High-lead meat from four deer had isotope ratios matching bullets from the same boxes and differing from bone lead.

Processed loin kept fragments in 4 of 16 carcasses with spine-adjacent fragments. The paper rates that at 8 percent among 49 steak packages from those deer. Separately the 2010 paper found metal in 32 percent of 238 Minnesota pantry packages. The CDC trip report says a physician found metal in 53 of 95 donated ground venison packets and later tests called it lead.

STEP 3 · Copper bullets

No lead showed in muscle from copper or enclosed cores

The agency page pairs copper bullets with a covered lead core. That pair averaged nine fragments and 7 inches as the average farthest distance from the wound channel. Copper pieces on the x-ray stayed inside one inch past the exit and both designs left no lead on that page. The 2010 muscle assay found no lead from the copper bullet or the enclosed-lead bullet.

The preliminary report recovered exited copper bullets in sand at 96 percent retained weight while two rapid-expansion rifle bullets held about 48 percent. Fragments from the rapid-expansion bullets and the breaking bonded bullet were found 5 inches to 14 inches past the exit. Our rule judges a bullet by lead meeting tissue and treats retained-weight lines as advertising.

Hunt and colleagues in 2006 radiographed deer killed in Wyoming and in California during 2002 through 2004 with expanding copper bullets, which left 6 fragments in 4 intact deer and one gut-pile fragment. Those four deer are the full copper sample, and the result runs in the same direction as the Minnesota muscle assays.

STEP 4 · Blood lead

North Dakota wild-game eaters were 0.30 µg/dL higher

In May 2008 the Centers for Disease Control and Prevention and the North Dakota Department of Health took blood samples in six cities after donated venison had been withdrawn. The Iqbal trip report used clinic visitors. Recruitment was 742 people with two Minnesota residents removed and 736 samples analyzed. Wild-game use was 80.8 percent of participants (598 people) and 98.8 percent of those eaters ate venison. The geometric mean for all participants was 1.17 µg/dL blood lead. Readings stayed at or below 10 µg/dL. During 2008 that figure was the CDC case-management threshold.

People eating wild game had 0.30 µg/dL more blood lead than people who did not after controls for sex and age and house age and lead-related hobbies. People who ate no wild game over the prior month had lower readings for every surveyed game type. Venison was on that list. The 0.30 µg/dL result is an adjusted association among these self-selected clinic participants. That adjusted association cannot forecast how one meal would change a person's blood lead.

The report says wild-game eating can push blood lead up. This group's 1.17 µg/dL geometric mean sat under the 1.60 µg/dL national CDC 2005 mean. Birds and other game were in the questions with venison. Children younger than 6 are treated as more susceptible to lead.

Hunt and colleagues fed four pigs fragment-containing venison and four control pigs fragment-free venison from the same deer in the same PLOS ONE paper. The abstract peak mean was 2.29 µg/dL in the fragment group with a high of 3.8 µg/dL and the controls averaged 0.63 µg/dL. The fragment group was above the controls on day 1 and day 2 and day 3. Lead from the packages reached blood in that four-pig test.

STEP 5 · Field rule

Wider cuts lower the grind count without clearing the deer

The preliminary report saw about a 5 to 20 percent drop in fragment counts after rinsing and almost no change in the farthest fragment. At 45 cm from the exit 2 of 80 unrinsed samples had detectable lead (called 3 percent) and 9 of 80 rinsed samples did (called 11 percent). Grund and colleagues tell hunters concerned with lead to avoid a cavity rinse. They say more work may be required to compare the harm of skipping the rinse with the harm of using it. Our practice is wiping the cavity dry on a lead-shot deer and keeping the hose away.

A 2-inch trim leaves most fragments because only about 30 percent of the Minnesota pieces sat that close to the exit. The Minnesota DNR states that routine trimming is likely to leave fragments behind, and the agency cannot name how far the cut should reach. Grund and colleagues got lead hits at the 45 cm station about 18 inches out and they stopped sampling there. They judge that any meat on a deer shot with lead can hold at least some lead. Our rule leaves the bloodshot channel plus a wide margin out of the grind which cuts burger fragments without clearing the deer.

Minnesota kept three pelvis shots out of the main figures. The agency page says a hindquarter hit threw so many fragments a hunter would likely discard that meat. One rapid-expansion hindquarter muscle hit in the preliminary note still fragmented hard and the slug broke femurs while fragmenting less. A broken hip means a wider discard or dropping that quarter.

Have a veterinarian x-ray one channel package and one keep package from the same deer. Bullet laws differ among states so read your own wildlife agency's current rules before you purchase a box.