Study shows hunters are poisoning their families with lead-laced meat

Dr Eric Buenz, the Research Professor of Applied Industries at the Nelson Marlborough Institute of Technology (NMIT), undertook work to evaluate the health risks of eating wild game meat. He compared lead ammunition with a copper alternative.

‘Hunters talk about weight retention in bullets, which is around 70% for a lead bullet, as a medical scientist I ask them where did the other 30% of the lead go? Well, you're eating it,’ exclaims Buenz.

Working in partnership with neurologist Gareth Perry, also at NMIT, Buenz wanted to find out if using copper ammunition instead of lead bullets results in lower blood lead levels.

A fortuitous meeting of a fellow hunter near Motueka allowed him to turn his theory into an applied research project. 

Greg was the perfect subject. He had eaten a diet of nearly 100% meat for the last four years, to the exclusion of other food groups. For the last two of these years he existed solely on meat shot with lead ammunition. During these latter years, he experienced the onset of significant health problems, such as unexplained weight loss and gout. Under Buenz’s guidance, Greg converted to non-lead ammunition and his blood lead levels were tracked.

‘The first results came back, and this guy’s blood lead levels are almost like Chernobyl, so he had to be eating lead from somewhere,’ says Buenz.

In order to determine exactly how much lead the hunter was ingesting, Buenz did two things. Firstly, he took mince from the hunter’s freezer and x-rayed it.

‘It was like looking at a starry night on the x-ray but using x-ray we couldn’t confirm if the metal in the meat was lead or another type,’ explains Buenz.

Secondly, to confirm that it was the ammunition impacting the lead levels, three wild goats were shot using Greg’s bullets. They were processed into mince in Greg’s usual manner, including the removal of large metal fragments.

Buenz then had lead levels in both the mince from Greg’s freezer and from the goats tested in a laboratory. The results showed that Greg had indeed been consuming a lot of lead and that it was due to the lead bullets.

Buenz then taught Greg to reload non-lead ammunition using copper bullets to eliminate the lead exposure through eating meat he was harvesting.

During the study Greg maintained his carnivorous diet. Since conversion to non-lead ammunition, his blood lead level decreased significantly. His health issues have also resolved.

Buenz estimates it will take 16 years for Greg’s blood lead level to return to normal.

The team published two papers in The American Journal of Medicine and were the first to demonstrate the relationship between eating meat shot with lead ammunition and elevated blood lead levels. This month they published a two-year follow-up study in the Internal Medicine Journal.

Buenz is now part of a European-based international consortium that funds research projects working to reduce lead exposure from shot animals. He provides insights on the impact of lead ammunition on human health.

Closer to home, Buenz is on a mission to replace lead bullets with copper through both education and legislation. He has found that it is hard to change the attitudes of hunters.

With the aid of funding from a private donor, he is working with a barrister to change legislation to eliminate the use of lead ammunition on crown-owned land. The dispersal of lead into the natural environment is a significant factor in the lead poisoning of kea and other wildlife that eat Department of Conservation culled deer, pigs and goats.

Buenz hopes that a change in government legislation will start to shift hunters’ attitudes and simultaneously make copper ammunition more readily available as an alternative.

• Dr Eric Buenz runs the Applied Research Training Scheme at NMIT. He works with participants to develop their research writing and publication skills through 1:1 mentorship. Most participants in the training go on to publish their work from the course in a peer-reviewed journal. Applications are welcomed from across the ITP sector.
  
  
• Dr. Eric Buenz holds a Doctorate in Biomedical Science from the Mayo Clinic College of Medicine, a Master of Business Administration from the University of St. Thomas, both in Minnesota, USA, and a Master of Agriculture from the University of the South Pacific in Samoa. Currently Eric is the Research Professor of Applied Industries at the NMIT in Nelson. Email Eric Buenz.
  
  
• Visit NMIT's website.