The North Dakota Department of Health (NDDH) and the Minnesota Department of Natural Resources (MN DNR) have recently released independent studies that provide recommendations for minimizing lead exposure to hunters and other individuals who consume game meat harvested with lead-based bullets, reports the Wildlife Management Institute. Both studies began following the discovery of lead fragments in venison donated to North Dakota and Minnesota venison donation programs in March 2008.

In early October, the MN DNR completed an assessment of lead fragment levels in deer and sheep carcasses that had been shot using various combinations of commonly used firearms and ammunition. Using radiography, researchers detected lead in tissue samples," as much as 18 inches away from the exit wound, and noted that most of the particles were too small to see or feel. However, "the probability of having a tissue sample test positive for lead at 10 inches was quite low (~7%)." The study also found that rinsing the wound channel reduced lead fragments locally but seemed to increase lead contamination in other areas of the carcass. Surprisingly, trimming 2 inches of material around the wound channel eliminated only 30 percent of lead contamination.

In an effort to shed light on the potential health risks caused by the presence of lead in game meat, the NDDH and the U.S. Centers for Disease Control and Prevention (CDC) began a study on May 16, 2008 to "determine whether an increase in blood lead levels (PbB) is associated with the consumption of wild game."

Released November 5, the study found that, of the 736 participants who volunteered to have their PbB tested, those who consumed game meat harvested with lead bullets had somewhat higher levels of lead in their blood than did those who consumed little or no game meat. Additionally, higher PbB were associated with more recent consumption of game meat.

No individuals participating in the study showed PbB above 10 micrograms per deciliter, the CDC recommended threshold for individual case management, and those who consumed game meat had only 0.3 micrograms per deciliter higher PbB than did those who had not consumed game meat. Due to a limitation in study participants, a trend toward higher PbB in children could not be confidently determined.

"Ingesting lead particles in game meat is not the most important source of lead exposure to humans," said Dr. Stephen Pickard, M.D., epidemiologist for NDDH. "Sources like lead-based paint are far and above more critical, but lead particles in game meat are a real source."

Both the North Dakota and Minnesota studies contain recommendations for hunters and others who consume game meat harvested with lead-based bullets. Among the recommendations is an advisory that children under the age of six and pregnant women should not consume game meat harvested with lead bullets. The studies encourage liberal trimming of wound channels in game harvested with lead-based ammunition. Also noted was that ground venison is the most likely of meats to contain lead. Other sources recommend that the grinding surfaces of meat processing equipment be cleaned routinely, perhaps even between individual cuts of meat. ?
To read the full list of recommendations from the each of the studies, visit the following websites: http://www.dnr.state.mn.us/hunting/lead/index.html (for the MN DNR bullet fragmentation study) and http://www.ndhealth.gov/lead/venison/ (for the NDDH study). (mcd)