Authorities in eastern Attica yesterday prohibited bathing off the coast of Anavyssos, near Sounion, after tests on sea water there revealed traces of the highly toxic chemical arsenic.

Local authorities referred to a “discharge” of water running into the sea. It was unclear whether the source of this discharge was an industrial waste pipe.

A second round of tests on seawater in the area revealed smaller traces of arsenic than the original tests, authorities said.

But swimming will be forbidden in the area for the time being as the Hellenic Center for Marine Research conducts further tests on the water to determine whether it poses a public health risk and to attempt to identify the source of the chemical.

A delegation from the Hellenic Ornithological Society is to visit the area today to inspect several dead birds that have washed up on the shore in recent weeks.