These oils have been targeted in the government's White Paper for Energy for use in fleets maintained by local authorities and public bodies.

But, according to Professor Austin Darragh, "these toxins could do irreversible damage to people if this goes unchecked. I'm so concerned about this as a physician that I contacted a number of ministers and the Taoiseach. They all passed the buck except for the Department of Transport. At the moment, I'm concerned for all my countrymen. We run the risk of the next generation of people born being genetically affected if this goes unchecked, " he told the Sunday Tribune.

The research that caused Prof Darragh such concern and prompted him to immediately inform government was carried out by Dr Jurgen Bunger at the University of Bochum in Germany. The recently published report states: "The use of pure rapeseed oil as a transport fuel is a health hazard to all employees who drive such vehicles on a daily basis and who are exposed to exhaust fumes. Workplaces where diesel engines are fuelled by pure plant oils and are not well aerated should be considered to be dangerous as well.

In such places, workers are directly exposed to the cancerogenous fumes."

At present in Ireland, some farm machinery and commercial vehicles use pure plants oils and rapeseed as it is more economical. "Around Ireland, bio-fuels are being produced. I do not think it is safe. It is mostly being used for farm machinery but now the government proposes to use it for public transport. It is a major worry, " said Prof Darragh.

Following Prof Darragh's representations to government, the sustainability adviser to the Department of Transport, David Browne, contacted him via an email seen by the Sunday Tribune to say he was "quite alarmed" by the implications of the new research.

He assured Prof Darragh that the matter would be given "full attention" and he was putting together an inter-departmental group to meet with Prof Darragh and his UL colleague, Prof Michael Hayes.

On Friday, the government-funded German-Irish chamber of commerce announced that 42 vehicles had been selected in Ireland for a pilot project to run on pure plant oil by the end of July. The selected vehicles represent about 30 Irish companies from 15 counties.

Green Party deputy leader Cllr Mary White (Carlow) has converted her Volkswagen Golf to run on 100% rapeseed oil. "I purchased it from a farmer in Kilkenny who produces it.

He also supplies it to a garage in Carlow. A lot of trucks and farm machinery in my area use pure plant oils.

More privately owned cars are also using it than you think, " she said.

White said she was not aware of any dangers associated with using rapeseed or pure plant oil as a fuel. If elected, she said the Green Party would "commit oil companies to include a minimum 5% blend of biofues in any fuel supply".