Fluorescein, a non-toxic substance used in tests in sewer networks, was detected. Toxic elements were not detected in the samples.
The incident is reminiscent of a protest action from the 60s. In 1968, the Argentine artist Garcia Uriburu poured bright green dye into the water to raise awareness of environmental protection. The Grand Canal had already been turned green a good five decades ago. The mystery of the green-discolored section of the Grand Canal in Venice has been solved.