"Passengers on a cruise ship could be inhaling “60 times higher concentrations of harmful air pollutants ” than they would in natural air settings, Naturschutzbund Deutschland (NABU), a German environmental association, has warned."
"He warned that the latest results are most likely indicative of the poor air quality on nearly all cruise ships."
"But Helge Grammerstorf, the German national director of the Cruise Lines International Association (CLIA) and a former ship captain and ship broker, denied the validity of the measurements, arguing that a more systematic test over a longer period of time is required rather than the recent selective sample of measurements taken.
“We don't know these measurements. The claim is completely unsubstantiated,” he told Hamburger Abendblatt, a German daily newspaper."http://www.telegraph.co.uk/travel/cruises/news/air-pollution-levels-200-times-higher-on-cruise-ships/