Monday, October 16, 1995 BRUSSELS, Belgium (Reuter) -- France's south Pacific nuclear weapons test site is unstable and there is a risk of landslides and tidal waves which could submerge Polynesia, a French vulcanologist said Monday. "This is an unstable atoll...I would say that this situation constitutes a high risk," Pierre Vincent, a professor at the University of Clermont-Ferrand told a European Parliament hearing on French nuclear tests in the South Pacific. "All the factors which we now know favor destabilisation in volcanoes are gathered together at Mururoa," he said, pointing to the atoll's steep sides, fissuring in the atoll and alteration of its substructure by previous tests. "The shockwave from a new explosion...could be the trigger which would cause the detachment of (previously disturbed sections of rock)," he said. Such landslides could cause "tsunami," seismic waves from undersea earthquakes or landslips, which could "submerge the whole of Polynesia," Vincent said. Even an immediate halt to France's current series of tests in the region would not remove the risk, the professor added. France has so far carried out two of what it says will be a series of up to eight nuclear tests on Mururoa and Fangataufa atolls, sparking off worldwide condemnation. Vincent said current levels of radioactivity were not necessarily a problem but the risk of landslides was. "There's probably not a lot of pollution. My point of view is that it is high time to stop. If we stopped tomorrow, if that could happen, we would certainly have to continue to monitor this atoll for decades and probably a lot longer than that," he said. Swedish Professor Elis Holm, who told the hearing he had eaten lobsters caught in Mururoa's lagoon, said radioactivity levels measured in fish and other sea creatures did not present a human health risk. Holm, a radiation specialist from Sweden's University of Lund, said radioactivity levels in fish, clams and lobsters in the lagoon were "maybe slightly enhanced compared to what is expected." He said this could be due to earlier French nuclear tests in the atmosphere or from British or American tests in the southern hemisphere. Euro-deputies also questioned Augustin Janssens, leader of a European Commission experts' mission to Mururoa last month which returned saying it had been denied full access to test sites and radioactivity monitoring facilities. "For the Commission, the data is not complete," he said, adding: "We made our reservations because we have not been able to meet fully our objectives. This does not imply that the Polynesian population are not well monitored." The European Commission asked France for outstanding data last week and will decide its next step October 23.