IMPACT OF EMISSION FROM OIL SHALE FUELED POWER PLANTS
ON THE GROWTH AND FOLIAR ELEMENTAL CONCENTRATIONS
OFSCOTSPINEINESTONIA
KATRI OTS
Department of Ecophysiology, Forest Research Institute, Estonian Agricultural University,
Viljandi mnt. 18b, Tallinn, Estonia, e-mail: Katri.Ots@rmk.ee
(Received 8 January 2001; accepted 17 January 2002)
Abstract. To study the impact of air pollution on the growth and elemental composition of conifers,
5 sample plots were established at different distances and directions from the Estonian Power Plant
(Northeast Estonia) in 1999–2000. The selected stands were 75–80(85)-yr-old parts (0.05 ha) of
(Oxalis)-Myrtillus site type forest of 0.7–0.8 density. The soils of all sample plots were Gleyic
Podzols (Lkg) on sands. The several times higher Ca concentration in the humus horizon of the
sample plot NE from the Estonian PP is caused by the prevailing westerly and southerly winds which
carry more pollutants NE from the power plant than to SSW. To ascertain the effect of power plants
on the growth of Scots pine (Pinus sylvestris L.), the length growth of the needles and shoots formed
in 1997–2000, dry weight of 100 needles, and density of needles on the shoots were measured. As
compared to the control, the strongest inhibition of growth was revealed in the sample plots situated
22 km north-east and 17 km south-west from the Estonian Power Plant. As compared to control, the
needles of trees growing on sample plots closer to the power plant showed higher contents of Ca,
S and Zn. The content of Mg in needles increased with distance from the pollution source. Current
year needles had higher contents of Cu and Zn than older needles. Today the amounts of fly ash
emitted from Narva power plants are fallen. Long-term fly ash emission has caused changes in the
measurements of morphological parameters and chemical composition of needles.
Keywords: biomass, fly ash, mineral elements, oil shale fueled power plants, Pinus sylvestris
1. Introduction
Environmental pollution that was one of the key issues for decades has by today
lost some of its acuteness. However, this is not true for Estonia. The major pollution
sources in the north-eastern part of the country are two oil shale fueled power
plants near the town of Narva – the Baltic (commissioned in 1959) and the Estonian
(1969) Power Plants (PP). The marked rise in the production of electric power
in the 1970s polluted the air not only in Northeast Estonia but also in the whole
area of the Gulf of Finland as the flue gas from high stacks (Baltic PP 150 m,
Estonian PP 300 m) spread over hundreds of kilometres (Anttila et al., 1996). A
characteristic feature of power plants is high concentration of sulphur compounds
and fly ash in the flue gas emitted into the atmosphere from the stack (Ots, 1999;
Agrawal and Singh, 2000). The large amount of fly ash in the emissions from oil
shale fueled power plants is due to a high concentration of ash (40–50%) in the oil
Environmental Monitoring and Assessment 85: 293–308, 2003.
© 2003 Kluwer Academic Publishers. Printed in the Netherlands.