With the “early antlerless” deer season opening Saturday, results of a preliminary study about how certain bullets break up and disperse on impact provide more information for hunters heading out to the field.

The results add emphasis to previous venison safety messages from the Minnesota Department of Health recommending pregnant women and children under six do not eat any venison harvested using ammunition that results in deposition of lead particles in meat.

There is currently no health-based standard or guideline for consumption of lead fragments by older children or adults, according to the MDH.

The Minnesota Department of Natural Resources conducted the research this spring to offer more detail to hunters in response to earlier concerns about lead particles in hunter-harvested venison donated to local food shelves.

The research indicates lead particles are commonly found farther from the wound channel than many hunters might assume and that the number of lead fragments varies widely by bullet type. Hunters with concerns about these findings can use this information to minimize exposure to lead fragments through ammunition selection.

In addition to showing increased fragmentation by some lead bullets, the DNR study indicates that most lead particles in venison will be too small to see, feel or sense when chewing.

Results of the study showed that shotgun slugs and muzzleloader bullets generally fragmented much less than high-powered rifle bullets, said Lou Cornicelli, DNR big game program coordinator and study participant. Much of southern and western Minnesota is in the shotgun zone.

“We wanted to be as responsive as possible to hunters in providing this information before deer season,” added DNR Commissioner Mark Holsten. “However, everyone must use their best judgement about the ammunition they use and how they dress and process their own venison.”

The controlled study, the first of its type, involved the shooting of different types of .308 caliber rifle bullets, a 12-gauge shotgun slug and two types of .50 caliber muzzleloader bullets into the carcasses of previously euthanized sheep.

Sheep were used as surrogates for white-tailed deer because they have similar anatomy and weigh about the same as mid-sized deer. Researchers then shot deer from a standard distance. Sheep were X-rayed at the University of Minnesota Small Animal Hospital to determine the number of fragments and the degree of fragmentation. The University of Minnesota Veterinary Diagnostic Laboratory completed the chemical analysis of lead levels.

Exposure to lead can be harmful for both children and adults, and it may not always produce visible symptoms, according to the MDH.

Pregnant women and younger children are especially sensitive because they absorb most of the lead they take in, and the brains of infants and young children are still developing.