Nuclear Test veteran Roy Sefton points to an image of a laboratory slide showing one of his cells about to devide. There are two nuclei as there should be, but clustered at the bottom are seven micronuclei, scientific evidence of a breakdown in his DNA. When he first saw that his DNA could not repair itself, Sefton said, "it frightened the hell out of me".

This cell in its dysfunctional state gives Sefton a scientific explanation for his chronic ill health. He hopes the Massey University research team led by Al Rowland will find sufficient evidence to prove New Zealand's nuclear test veterans suffered significant genetic damage from their exposure to nuclear radiation.

Sefton's voice breaks. "It's been a wasted life. What makes it difficult is to have battles with politicians who do not believe we have been exposed to radiation."

New Zealand leads the world in its analysis of genetic damage from historic nuclear exposure.

Five years ago. the NZ Nuclear Test Veterans Association commissioned Rowland, internationally recognised as one of the top 20 molecular geneticits in the world, to carry out research to see if exposure to radiation had caused genetic damage in the veterans.

Rowland was ambivalent. He did not think he would find any impact on the DNA, 50 years after exposure. "It was such a long time ago I thought it would be a bit like looking for a needle in a haystack," he says.

In his Palmerston North laboratory, Rowland and his team of six scientists are trying to discover if exposure to nuclear radiation can cause long-term genetic damage.

They are test blood cells taken from 50 New Zealand nuclear test veterans and a control group of 50 ex-military men to see if there is more genetic damage to the DNA in the chromosomes of the veterans than there is in the control group.

They are studying breaks in the DNA to see if genetic material from one chromosome has moved to another chromosome and attached itself there. This process, called translocation, can occur in the presence of radiation.

Rowland said genetic translocation could have a dramatic impact on health. "It can create a pre-cancerous state."