The concentration of zinc, copper, aluminium and iron has been below threshold value in water samples taken from the Szamos River near Csenger at the Romanian border, in north-eastern Hungary, the national disaster management authority OKF said on Thursday. The authority earlier reported above-threshold values of zinc, copper, aluminium and iron in samples taken early on Thursday. OKF said in a statement that it would continue monitoring any changes in the environment. The national water management authority (OVF) said on Wednesday that it had been alerted of heavy metal pollution arriving in Hungary in the River Szamos from Romania. The Romanian side had sent information over the Principal International Alert Centre (PIAC) showing that heavy metal pollution resulting from mining spoil was expected to arrive in Hungary. The pollution reached Hungary at 1am on Thursday.