Lead ammunition debate keeps raging on

The National Rifle Association, the National Shooting Sports Foundation and the United States Sportsmen's Alliance have worked overtime in recent weeks to dispel the suggestion that wild game shot with lead ammunition threatens human health. Maybe they're correct. Or maybe they're just saying what they get paid to say by the ammunition industry.

The most recent lead ammunition brouhaha arose last year in North Dakota. Reports of lead fragments in deer killed there with traditional lead bullets eventually led to a ban on those animals being contributed to the state's food shelf program.

In recent weeks, the Minnesota Department of Natural Resources and the Minnesota Department of Agriculture announced that venison contributed to this state's food shelves will be X-rayed, and that any meat found to contain lead will be destroyed.

The NRA and others counter that all of this is much ado about nothing, and that lead bullets and shots shells have been used to kill game since time immemorial, and no human has fallen ill yet.

On Thursday, the United States Sportsmen's Alliance fired the latest salvo in defense of ammunition makers, issuing a press release denouncing Minnesota's "overreaction'' and "hysteria'' and its decision to "expand X-ray testing to all venison donated to Minnesota food shelters.''

The primary constituency of the NRA and the other groups -- hunters and shooters -- would be better served by these organizations if accurate, complete information were offered to them on this important subject, so they could decide for themselves whether game killed with lead ammunition presents a threat.

Example: In Canada, considerable research has been done on game killed with lead shotshells and (less so) lead bullets, and the correlation to increased blood-lead levels among people who have eaten it.

Most of this work has been done on First Nation (Native American) communities in the sub-arctic. It's there that many communities feed on lead-killed game for months at a time. Much of the consumption is of geese killed with lead shot shells (lead shot shells are illegal for waterfowl hunting in Canada, as they are in the U.S., but native hunters prefer them because of their low cost and perceived greater killing power).

Many of these northern people have relatively high blood-lead levels, said Bruce Wainman, an author of a study published last February concluding that "past studies that suggested that lead shot shell was the main source of lead in subsistence harvesting groups must also recognize that lead-contaminated meat from game harvested with lead bullets may also be contributing to lead body burden in these groups.''

In a phone interview, Wainman, a professor of pathology at McMaster University in Hamilton, Ontario, said he is a hunter. He was unaware the NRA and other groups are suggesting the blood-lead debate is being fueled by anti-hunters.

Wainman said he has studied lead and lead-related issues for more than 15 years. In that time, he said, the perceived safe blood-lead level has been lowered by government authorities 10 or more times.

"We don't know what a truly safe level is,'' he said. "We know that higher lead levels in blood are associated with lower intelligence. But we don't know exactly whether it is directly toxic to brain cells, or whether acute exposure is worse, or chronic exposure.''

Kids and particularly infants are at particular risk, and the fetuses of pregnant women. "Personally, I'm not so worried about myself because I might only have a dozen or so game meals a year,'' he said. "But I am very careful with my children.''

A bird hunter, Wainman said lead shot likely someday will be outlawed for pheasant, grouse and other upland species, as it has been for waterfowl (lead shot is prohibited for waterfowling because it kills ducks, eagles and other birds that ingest the spent pellets).

A similar study published in 2005 looked at blood-lead levels in subsistence hunters in Greenland. "Blood lead was low among those not eating birds. Among those reporting to eat birds regularly, levels were [up to nine times higher]. ... This clear relationship points to lead shot as the dominating lead source to people in Greenland.''

Yet little about this conflict is absolute. A 2002 Swiss study of hunters who ate game shot with lead ammunition found no correlation to the amount of lead in their blood vs. people who didn't eat game.

That said, a 2001 study of First Nation communities in the western James Bay region of Canada concluded, "Clearly, any game species harvested with lead shot shell [and perhaps other types of leaded ammunition] risks contamination from the embedding of whole pellets and/or fragments in the tissue and constitutes a human health concern.''

Dennis Anderson danderson@startribune.com