Impact of acid sulfate soil catchments on water quality in a lake in western Finland; trends and total metal load

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Janne Toivonen, Sören Fröjdö, Peter Österholm
Publisher: Boreal Environment Research Publishing Board.
Place: Helsingfors
Publication year: 2019
Journal: Boreal Environment Research
Journal acronym: BOREAL ENV. RES.
Volume number: 24
Start page: 79
End page: 99
eISSN: 1797-2469


Acid sulfate soils occur worldwide and can cause serious ecological damage by releasing
acidity and toxic metals into watercourses. This study focused on short- and long-term
changes to the water quality of a lake in western Finland. Here, a decline in water quality
took place in the late 1960s. Since then, events concerning poor water quality have frequently occurred. The annual load of some potentially toxic metals varied from hundreds
of kilograms to thousands of tons, depending on the metal. The proportion of low-order
streams draining the nearest field to the lake is only 7% of the catchment area, while the
share of the total metal load was estimated to be over 30%. This points to the importance
of monitoring small coastal catchments. High runoff conditions were proven to be more
important in terms of water quality than occasional summer droughts. During the past
decade, acidic conditions have become more prolonged in the autumn, which is in line with
a predicted scenario relating to climate change.


Last updated on 2020-14-07 at 04:34