Unmonitored emissions from industrial sites in Koropi, east of Athens, are polluting underground water supplies with a potentially carcinogenic compound of the mineral chromium, according to a report made public yesterday.

The state environmental inspection service said it found reduced chromium in six water wells in Koropi, sometimes in concentrations above the permitted rate of 50 milligrams per liter.

“European law demands that such dangerous waste be treated before its release into the environment,” Constantinos Methenitis of Athens University told Kathimerini.

Reduced chromium poses a risk to those who drink or wash with water containing it or who breathe it in its gaseous form, Methenitis said.

Prefectural authorities said they had closed one of the wells in Koropi.