Polish authorities have refuted claims made by their German counterparts that mercury in the Oder River may have been responsible for the death of thousands of fish in recent weeks.
German tests show the presence of mercury and authorities said standards for surface waters had been breached.
Tons of dead fish have been found since late July in the river, Poland's second-longest, a large part of which acts as a border with Germany.
Tests, conducted on a continuous basis since Aug. 10 by the Polish Central Research Laboratory of the Chief Inspectorate of Environmental Protection, did not confirm the presence of mercury, the authority said on Monday.
It added that the Germans' sample collection points were not in the main part of the Oder, but in its tributaries and oxbow lakes.
Poland’s Environmental Minister Anna Moskwa, speaking after meeting her German counterpart in Szczecin on Sunday, said "as of today, none of the (water) tests have confirmed the presence of toxic substances … At the same time, we are conducting tests on fish. We have completed tests for mercury and heavy metals. Neither mercury nor heavy metals were found in the collected samples.”
Moskwa said checks for about 300 more substances would be carried out.
Entities which run businesses and industrial activities along the river are being checked, she added.
Mateusz Morawiecki, Poland's prime minister, has said his government would tighten laws against the illegal dumping of waste into rivers, and the subject would be debated in a Cabinet meeting on Tuesday.
According to Steffi Lemke, the German environment minister, a meeting of the International Commission for the Protection of the Odra River against Pollution (ICPO) has been scheduled for Thursday.
Source: Anadolu Agency