Ukraine's national rail company Ukrzhelesnitsia, citing a potential radiation hazard to engineers, today halted all freight train traffic to Slovakia, according to dpa. Management at Lvivska Zheleznitsia, the western section of the Ukrainian railroad, said Slovak use of TINSCAN RF6010 scanning machines posed a health threat to Ukrainian staff, the Interfax news agency reported. Slovak Embassy staff in Kiev declined comment on the Ukrainian transit ban. Passenger trains were still moving normally in both directions, but westward-bound freight traffic at the Uzhgorod-Matovce checkpoint, the main rail crossing between Ukraine and Slovakia, was halted completely, Channel 5 television reported. Dozens of freight trains were idling on sidings near the Slovak frontier in the hours after the ban went into effect, according to eyewitnesses speaking to a TV reporter. Lvivska Zhelesnitsia said in a statement that Ukraine would re-open rail freight traffic into Slovakia only after Slovak border personnel stopped scanning engines and train cars with Ukrainian railroad workers aboard, or began using a less dangerous scanning device. Slovak border inspectors began using the TINSCAN machine in early January to inspect train cars and engines hauling freight from Ukraine into the European Union, according to an article in Gazeta Po-Kievsky newspaper. Ukrainian rail workers exposed to the Slovak scan were subjected, sometimes daily, to radiation levels between six and 30 times greater than permitted under Ukrainian law, according to the newspaper report.