In order to measure concentrations of heavy metals in moss, several nationwide surveys have been carried out since 1977. Concentrations of mercury in moss remained more or less unchanged from 1985 to 1995, then generally dropped from 1995 to 2000. Results from 2005 were about the same as for 2000, including the local depositions in Odda.
Concentrations of mercury
micrograms per gram moss
Source: Climate and Pollution Agency. The map is an animation that shows the reduction in acidification in Norway. If you cannot see the animation, you may need to change the settings of your web browser. In Internet Explorer, choose Tools -> Internet options -> Advanced, and tick the check box “Play animations in web pages”.