Some 42 months after the global sulphur cap became law, researchers continue to uncover the enormous damage scrubbers are doing to the world’s oceans.

A new study from Chalmers University of Technology in Sweden focusing on four ports calculated that water discharged from scrubbers accounted for more than 90% of the contaminants found in water samples.

“The results speak for themselves. Stricter regulation of discharge water from scrubbers is crucial to reduce the deterioration of the marine environment,” said Anna Lunde Hermansson, a doctoral student at the Department of Mechanics and Maritime Sciences at Chalmers.