A planning inquiry into a proposed goldmine in Greencastle, County Tyrone, has heard conflicting assessments of the health and environmental risks associated with tellurium, a rare metal that would be extracted as a by-product.

Dalradian Gold Ltd, the applicant, estimates that 35 tonnes of tellurium could be recovered over the mine's 25-year operational life. The metal, which is as rare as platinum in the Earth's crust, is used in solar panels and electronics.

The Northern Ireland Environment Agency's Industrial Pollution and Radiochemical Inspectorate told the inquiry at the Strule Arts Centre in Omagh that tellurium poses a minimal radiological risk and that there are no significant dangers to the environment or human health.

However, objectors disputed those findings. Dr Alan Evans, a retired GP speaking for the Save Our Sperrins campaign, said tellurium has a narrow therapeutic window and can cause kidney problems, seizures and headaches. He warned it could enter the food chain through waterways, but acknowledged that knowledge about the mineral is limited due to its rarity.

Independent objector Pat Haughey argued that the mineral could be particularly hazardous for mine workers and that sampling conducted by the applicant was inadequate. Another objector, Martin Tracey, raised concerns about transporting tellurium-containing aggregate and the risk of a road incident in the Greencastle area.