A Motueka hunter has been found to have lead levels at more than 14 times the recommended limit after eating a diet of mainly wild game meat.
Eric Buenz, from the Nelson-Marlborough Institute of Technology, co-authored a paper in The American Journal of Medicine, about the experiences of Greg, a hunter he met in the bush.
Professor Buenz told Nine to Noon Greg had a level of 74.4 micrograms per deci-litre of lead - the New Zealand limit is 5 micrograms per deci-litre of lead and the average person has around 1 to 2 micrograms per deci-litre of lead.
Greg said he had been eating large amounts of game meat due to a carbohydrate intolerance. He had lost around 14kg in the past five years and suffered from gout, but couldn't explain why.
"While I was losing weight I had no choice, I just accepted it," he said.
After having his blood tested by Prof Buenz he switched to copper bullets for his hunting and began to see his health improve.
"Since May, when it was first discovered, I've put on 8kgs, so I've still got a bit to go.
"It's purely because of the reduced lead levels," he said.
Greg said the high levels of lead in the meat were preventing his kidneys from excreting purines in the meat.
He said he'd been warned several years ago about the dangers of lead in meat and went to a doctor to get a blood test, but was put off by the $80 cost and didn't think he was suffering any symptoms.
"I thought, well I haven't had any of that, no problem I'll eat it, it was going to cost $80 so I thought I'll leave it.
"I should have done it then," he said.
Greg said he would always take care to remove the pieces of lead he found in any meat he hunted.
"I'd never actually eat it, I'd spit out, so I thought 'well I spit it all out anyway' but that wasn't actually the case.
"Especially the high velocity bullets, when they hit the meat ... the lead sort of vaporises throughout the meat, so you don't actually know you're eating it," Greg said.
He said there was a lack of awareness among hunters about the dangers of lead bullets.
"We've got rid of our lead in paint, cosmetics, we used to have lead on our roofs, lead piping - we've got rid of all of that ... so we know that lead's bad - why do we still use lead bullets?"
Prof Buenz said high levels of lead affected people in different ways but would likely have a much greater impact on children.
"Older people do a much worse job of absorbing lead, it's the children who do a great job of absorbing it and it's only a really little bit that's necessary in order to cause problems," Prof Buenz said.
New Zealand Deerstalkers' Association national executive Bill O'Leary said there was limited awareness about the problems that lead contamination could cause.
But sometimes non-lead ammunition, such as copper bullets, didn't always work for all hunting purposes, he said.
"When people go to hunt they go to kill an animal, they want to do it as efficiently and cleanly as possible and in many cases the copper bullets just don't do the job."
The association would be making more information available to hunters about the dangers of lead bullets, said Mr O'Leary.