Last year was a record season for cruise traffic to Sweden.
But with increased traffic comes also increased emissions.
SVT's review shows that last year international cruise ships were operating with the engines running in Sweden's three largest cruise ports - Stockholm, Gothenburg and Visby - for over 5,000 hours.
When SVT visits M / S Anastasia in the port of Stockholm, diesel-powered engines noise below deck to keep the ship's electricity running.
Follow down into the ship via the clip above.