Henry Vallius
Arsenic and heavy metal distribution in the bottom sediments of the Gulf of Finland through the last decades
SantraukaThe Gulf of Finland is known to have been under rather hard stress from the anthropogenic loading of harmful substances for many decades. The emissions are known to have decreased slight1y during the last two decades, but can that decrease be seen also in the sea floor sediments? In this study, heavy metal data from the early 1990s are compared with new research data from 2007–2009. Concentrations of most metals have decreased in the sea floor sediments through the last one and one-half decade. The situation is improving in general despite a drawback on cadmium; those concentrations have remained at levels much too high, with virtually no decrease in trend through the years. Lead and mercury on the other hand seem to have decreased even more than expected, which is a very good sign, given the harmfulness of these metals.