At least four quarries in Greece supply the Hellenic Railways Organization (OSE) and other public departments with asbestos-filled rocks, even though the use of the mineral is considered extremely dangerous and has been banned by local authorities, evidence obtained by Sunday’s Kathimerini showed. The news comes after recent confirmed tests that Greek train carriages being used on Balkan routes contained asbestos. Separate confidential test results carried out by the Institute of Geology and Mineral Exploration indicated that the gravel used by OSE on some of its train lines contained asbestos levels of between 12 and 28 percent. It was originally thought the gravel was supplied only by one quarry in the prefecture of Magnesia, but new evidence shows that there are at least three more – in Macedonia and on the island of Aegina – that supply government departments with the carcinogenic material. The operation in Magnesia has since closed down. The dangerous nature of the gravel was allegedly known by OSE officials, who tried to bypass the problem by mixing the gravel with other materials imported from countries such as Romania or Cyprus.