The effects of the emissions of the Kostomuksha mining complex on the chemical composition of deposition and soil water in the surrounding pine forests

The Kostomuksha mining complex in Russian Karelia is a major emission point source surrounded by large forest areas near the Finnish border. The sulphur dioxide emissions of the complex are almost 60 000 tomes and dust emissions about 5 000 tonnes a year. Research into the effects of emissions on the surrounding forests were started in a Finnish-Russian co-operation project in 1992. Deposition measurements during the two first years indicate that the effects of the emissions extend about 30 km to the west of the complex. The annual sulphur deposition near the mining complex has been about 300 mg/m(2) in bulk precipitation and about 500 mg/m(2) in throughfall. Sulphur emissions sometimes extend the eastern parts of Finland, but there the deposition is clearly smaller than near to the mining complex. The high calcium emissions neutralize the acidifying effect of sulphur near to the mine and smelter. The iron concentration in precipitation also increased near the complex. Sulphur and calcium decreased in percolation water on moving westwards.