Lapin ympäristökeskus LAPIN YMPÄRISTÖKESKUKSEN RAPORTTEJA 5 | 2008 ISBN 978-952-11-3148-6 (nid.) ISBN 978-952-11-3149-3 (PDF) ISSN 1796-1971 (pain.) ISSN 1796-198X (verkkoj.) L A P IN Y M P Ä R IS T Ö K E S K U S Lapin ympäristökeskus PL 8060 96101 ROVANIEMI Puh. 020 690 173 As part of the larger project “The effects of the Kola air pollution sources in the areas of the Kola Peninsula and Finnish Lapland”, this study presents water quality data for 30 small lakes in Finnish Lapland during 1990–2006. From 1990 to 2003, sulphur emissions decreased 68 % and 82 % at Nikel and Monchegorsk, respectively. During the same period, the number of lakes with measured alkalinity below critical level (20 μeq/l) have declined in Finnish Lapland close to pre-acidi cation level. Effects of the Kola Air Pollution Sources in Finnish Lapland Surface Waters during 1990–2006 Juha O. Miettinen E F F E C T O F T H E K O L A A IR P O L L U T IO N S O U R C E S IN F IN N IS H L A P L A N D S U R F A C E W A T E R S D U R IN G 1 9 9 0 — 2 0 0 6 LAPIN YMPÄRISTÖKESKUS LAPIN YMPÄRISTÖKESKUKSEN RAPORTTEJA 5 | 2008 Effects of the Kola Air Pollution Sources in Finnish Lapland Surface Waters during 1990–2006 Juha O. Miettinen Rovaniemi 2008 Lapin ympäristökeskus LAPIN YMPÄRISTÖKESKUKSEN RAPORTTEJA 5 | 2008 Lapin ympäristökeskus Taitto: Ritva-Liisa Hakala Kansikuva: Myössäjärvi. Kuva Aarno Torvinen. Julkaisu on saatavana myös internetistä: www.ymparisto.fi/lap/julkaisut Yliopistopaino, Helsinki 2008 ISBN 978-952-11-3148-6 (nid.) ISBN 978-952-11-3149-3 (PDF) ISSN 1796-1971 (pain.) ISSN 1796-198X (verkkoj.) LAPIN YMPÄRISTÖKESKUS CONTENTS Introduction................................................................................................... 5 Material and methods .................................................................................. 8 Results ...........................................................................................................11 Meteorological data ................................................................................................... 11 Lake water data ...........................................................................................................13 Sulphate.............................................................................................................. 14 pH. .................................................................................................................. 15 Alkalinity........................................................................................................... 16 Aluminium........................................................................................................ 17 Copper................................................................................................................ 19 Nickel.................................................................................................................. 20 Other.metals...................................................................................................... 21 Discussion .....................................................................................................22 Recommendations for future monitoring .................................................24 References ....................................................................................................25 Documentation page ...................................................................................26 Kuvailulehti ...................................................................................................27  Lapin ympäristökeskuksen raportteja 5 | 2008 Lapin ympäristökeskuksen raportteja 5 | 2008 Introduction The.effects.of.the.Pechenga-Nikel.industrial.complex.and.Severonikel.Plant.of.the.Ko- la.GMC.in.the.Kola.Peninsula.(Nikel/Zapoljarny.and.Monchegorsk).on.freshwaters. are.studied.using.water.quality.data.in.lakes.in.the.Finnish.Lapland..The.study.is.part. of.the.larger.project.“The.effects.of.the.Kola.air.pollution.sources.in.the.areas.of.the. Kola.Peninsula.and.Finnish.Lapland”,.financed.by.the.Finnish.Academy.of.Sciences. for.the.years.2004–2007.. The.main.pollution. agents. from. the.Kola.Peninsula. are. acidifying.pollutants,. mainly.sulphate,.and.heavy.metals..From.1990.to.2003,.sulphur.emissions.decreased. 68%.and.82%.at.Nikel. and.Monchegorsk,. respectively. (Hole. et al.. 2006)..Despite. reductions.in.the.emissions.during.the.1990s,.non-ferrous.metal.production.remains. the.dominant.source.of.acidifying.gases,.mainly.sulphate,.to.the.atmosphere.within. the.arctic..Main. sources.of. acidifying.nitrogen. compounds. in. the.arctic. are. tran- sportation,.and.oil.and.gas.activities.(Hole.et al..2006)..However,.despite.the.local. emissions.most.of.the.acidifying.compounds.in.the.arctic.air.come.from.sources.at. lower.latitudes,.mostly.in.Europe,.North.America.and.Asia.(Hole.et al. 2006). High-latitude.ecosystems.are.particularly.sensitive.to.pollution..Highest.sulphur. deposition.in.Finnish.Lapland.was.measured.in.Vätsäri.area,.north.from.the.Lake. Inarijärvi,.at.distance.40–50.km.from.the.metal.smelters. in.Nikel. (Tuovinen et al.,. 1993)..The.Vätsäri.area.is.also.the.area.with.the.lowest.buffering.capacity.in.the.waters. (<50.μeq/l.in.many.lakes). The.first.signs.of.the.effects.of.acidic.deposition.in.Finnish.waters.were.noticed.in. the.early.1970s.(Kenttämies.1973)..Concentrations.of.all.measured.anions.and.cations,. except.bicarbonate,. increased. from.the. late.1960s. to. the.early.1980s. (Forsius.et al.. 1990)..In.the.1980s,.there.were.two.main.characteristic.in.the.deposition.of.acidifying. compounds. in. Finland:. decreasing. gradient. from. south. to. north,. and. elevated. deposition. in. northeastern. Lapland. originating. from.Kola. Peninsula. (Tuovinen. et al..1990). This.study.concentrates.on.lakes.in.the.southeastern.parts.of.the.Finnish.Lapland,. because.the.effects.of.the.metallurgical.industry,.most.closely.smelters.in.Nikel.and. Zapolyarny,.in.the.northernmost.Lapland.has.been.studied.by.the.Interreg.IIIA.Ko- larctic.project.“.Development.and.implementation.of.an.environmental.monitoring. and.assessment. system. in. the. joint.Finnish,.Norwegian.and.Russian.border.area. during.the.period.2003–2006.(Stebel.et al..2007)..In.the.vicinity.of.the.southeastern. Finnish.Lapland.is.situated.the.Severonikel.plant.of.the.Kola.GMC.JSC.in.Monche- gorsk. The.Severonikel.plant.is.the.largest.smelter.in.Murmansk.Oblast,.processing.rich. copper-and-nickel.ore.and.nickel.matte.from.Norilsky.Combinat.and.the.Pechenga- nikel.Plant..The.plant.announces.to.use.also.scrap.metal,.waste.and.raw.materials. from.domestic.and.international.suppliers..Wastewater.and.atmospheric.emissions. from.the.plant.are. formed.in.hydro-.and.pyrometallurgical.processing.of. the.raw. 6 Lapin ympäristökeskuksen raportteja 5 | 2008 materials. and. in. the.production.of. sulphuric. acid. from. the.production.waste.. In. addition,.heavy.oil.(230.000.tons.in.2002).is.burnt.in.a.heat.power.plant,.to.provide. heat.supply.and.partial.electric.power.supply.to.the.plant.. The. sulphate. and. metal. emissions. announced. by. the. Severonikel. plant. are. .presented.in.Fig..1.and.Fig..2..During.the.period.1990–2002,.sulphate.emissions.were. at.their.maximum.of.287.kt.in.1990,.and.declined.during.the.1990’s.to.below.50.kt/yr.. Copper.and.nickel.emissions.peaked.to.over.6.kt/yr.in.the.late.1980’s.,.but.declined. during.the.first.half.of.the.1990’s.to.below.1.kt/yr..According.to.Hole.et al..(2006),.the. development.of.the.emissions.from.the.more.northern.Nikel.smelters.has.followed. the.same.development.as.the.Monchegorsk.smelters. Fig. 1. Sulphate emissions from Monchegorsk combinate during 1972–2002. Source: Ministry of Natural resources official statistics; coal-fired power plant emissions: VTI/IVL, 2004. Fig. 2. Copper and nickel emissions from Monchegorsk combinate during 1972–2002. Ministry of Natural resources official statistics; coal-fired power plant emissions: VTI/IVL, 2004. 2002200019981996199419921990198819861984198219801978197619741972 300 250 200 150 100 50 0 SO kt4 2002200019981996199419921990198819861984198219801978197619741972 6 4 2 0 Ni Cu 8 kt Lapin ympäristökeskuksen raportteja 5 | 2008 The.most.dominating.direction.of.winds. is. from.west. in. the.area.of.Kuusamo,. southwest.from.Monchegorsk..Secondly.the.winds.prevail.from.the.east.(Fig..3).. In.1988,.the.total.sulphur.deposition.in.Svanvik.(northeastern.Norway).and.in.the. eastern.border.of.Finland.was.measured.to.be.around.60.meq/m2/yr.(Forsius.et al.. 1990)..According.to.Tuovinen.&.Laurila.(1992),.the.deposition.was.above.1,0.g/m2/yr. (20,8.meq/m2/yr).in.the.eastern.parts.of.Inari,.but.below.the.level.of.1,0.g/m2/yr.in. the.municipalities.south.and.west.from.Inari. The.alkalinity.values.consistently.increased.and.sulphur.concentrations.decreased. in.Finnish.Lapland.in.the.1990s,.indicating.recovery.from.the.acidification.(Tammi. et al. 2003)..Sulphate.deposition.decreased.at.Nellimö.(in.southeastern.part.of.Inari). from.0,33.g./m2.during.1981–1985.to.0,16.g./m2.during.1996–2000,.according.to.Fin- nish.Environment.Institute.data.(Tammi.et al..2003).Minnow.populations.also.showed. recovery.in.the.Vätsäri.area.in.the.late.1990s,.compared.to.1993.(Tammi.et.al..2003). Fig. 3. Percentage of time for each wind direction during 1961–1990 in Kolvanki, Kuusa- mo. Figure from the Finnish Meteorological Institute (1991). N E S W Wind < 1m/s: 11 % Wind > 1m/s_ 20 % 10 % The.acidity.of.Finnish.lakes.is.dependent.upon.the.atmospheric.loading.of.sulphate,. the.catchment.sensitivity,.and.the.amount.of.organic.anions.present.(Forsius.et al.. 1990)..Of. these,.sensitivity. is.dependent.on.soil.geochemistry,.catchment.size.and. runoff.rentention.time.(Kähkölä.1996).Of.lakes.with.pH.less.than.5,3,.56–81.%.was. estimated.to.be.naturally.acidic.(pH.<5,3).(Forsius.et al..1990).. Critical.load.is.defined.as.the.highest.load.that.will.not.cause.chemical.changes. leading.to.long-term.harmful.effects.on.the.most.sensitive.ecological.systems..For. sensitive.areas,.with.quartz,.granite,.or.gneiss.bedrock,.the.critical.load.is.estimated. to.be.in.the.range.20–50.meq/m2/yr,.e.g..in.Ähtäri,.southern.Finland,.20.meq/m2/yr. (Kauppila.et al. 1990). Arctic.Monitoring.and.Assessment.Programme. (AMAP).has. indicated. that. the. impact.of.the.oil.and.gas.industry,.and.natural.sources.including.forest.fires,.may. increase.in.the.future.(Hole.et al..2006)..Also.the.importance.of.nitroxen.oxide.emissions. is.increasing.in.the.arctic..These.reasons,.with.the.fact.that.most.pollutants.in.arctic. air.originate.from.sources.outside.the.arctic,.have.resulted.in.AMAP.recommending. monitoring.and.research.be.carried.out.to.provide.more.data.on.effects.and.trends.in. the.most.impacted.areas.of.the.arctic.(AMAP.2006).  Lapin ympäristökeskuksen raportteja 5 | 2008 Material.and.methods Altogether.30.lakes.were.studied.for.their.water.quality.(Table.1)..Five.of.the.lakes,. situated.in.western.Finnish.Lapland.(municipalities.of.Enontekiö,.Kittilä.and.Muo- nio),.are.used.as.reference.sites. Lake Municipality Coord. Coord. Area total P total N TOC Colour YK-North YK-East [ha] [µg/l] [µg/l] [mg/l] [mgPt/l] Kenttälammit Kotala Salla 7436528 3584872 2,1 9 480 6,1 15 Nuottalampi Salla 7409770 3560070 3,3 6 283 5,4 19 Pikku Haltiajärvi Salla 7466871 3603832 1,3 7 159 1,8 4 Ruuhijärvi Salla 7418379 3574123 66,4 13 548 4,1 11 Lastenlampi Posio 7328970 3536700 4,1 6 330 4,1 12 Miilulampi Posio 7338100 3554750 2,0 6 298 2,2 6 Näskäjärvi Ranua 7345500 3489000 547,9 7 248 5,3 37 Siurulampi Savukoski 7520802 3577241 4,5 16 557 8,7 54 Arvolampi Sodankylä 7508180 3522550 14,9 8 493 5,1 19 Auveelampi Sodankylä 7509480 3523900 9,2 10 228 6,7 58 Hankarimpilampi Sodankylä 7532270 3490420 9 518 7,9 48 Joutolampi 2 Sodankylä 7445590 3461860 13,1 17 754 10,7 81 Makiankalanlampi Sodankylä 7437340 3467550 9,5 17 472 13,6 132 Suopalampi Sodankylä 7442068 3460789 38,9 13 305 5,6 40 Joulujärvet V1 Inari 7706458 3584704 36,6 4 149 2,3 5 Kalaton Kampajärvi Inari 7627540 3560772 11,9 5 223 4,3 10 Keittämättömätjärvet Inari 7609250 3550160 17,8 6 306 5,0 24 Lampi 219 Inari 7708923 3584543 5,6 4 133 2,4 7 Lampi 222 Inari 7708833 3582618 23,6 5 123 2,1 7 Lampi 3/88 Inari 7709055 3583966 4,7 4 111 1,7 5 Lampi 432 Inari 7596380 3531710 5,9 8 426 6,5 28 Lampi D49 Inari 7619820 3552320 1,9 11 551 8,0 61 Peuranampumajärvi Inari 7627178 3564424 7,4 6 242 4,8 15 Sierramjärvi Inari 7678153 3496122 107,9 4 110 2,3 9 Äälisjärvi Inari 7707210 3580852 396,5 3 120 1,6 4 Hietajärvi* Enontekiö 7598784 3404554 5 2,3 5 Käyräjärvi* Enontekiö 7576341 3387159 7 400 7,2 31 Mustajärvi* Kittilä 7501251 3414022 3,6 9 352 5,5 33 Rautujärvi* Enontekiö 7588286 3360453 5 210 3,4 11 Sarvijärvi* Muonio 7559331 3379272 9 145 1,8 8 Table 1. Location, surface area, and water quality of the studied lakes. Reference lakes are marked with asterisk. 9Lapin ympäristökeskuksen raportteja 5 | 2008 Small.remote. lakes.with.no.significant.anthropogenic. impacts.and.oligotrophic. character.were.selected.for.the.study,.because.the.effects.of.the.airborne.deposition. is.most.easily.seen.in.these.lakes..The.study.lakes.are.included.in.the.monitoring. network.“Acidification.monitoring.of.surface.waters”.in.Finnish.Lapland. The.study.lakes.in.the.eastern.Lapland.are.situated.in.the.area.of.six.municipalities. (Fig..4)..Salla.is.the.closest.municipality.to.Monchegorsk,.forming.with.Posio.and. Ranua.southern.part.of.the.study.area..North.from.Salla.are.situated.Savukoski.and. Sodankylä,.situated.north.from.Monchegorsk.and.south.from.Pechenganikel..Inari. in.the.north.is.more.impacted.by.the.Pechenganikel.smelters,.and.is.studied.only.for. comparance.with.the.other.municipalities..The.reference.lakes.are.situated.in.Kittilä,. Enontekiö.and.Muonio.in.the.western.Finnish.Lapland... Only.late.summer.or.autumnal.data.(mostly.September–November).is.used..One. surface.sample.(0–1.m).from.each.lake.is.used.for.each.year.in.the.analyses..The.water. quality.samples.were.analyzed.in.the.laboratory.of.the.Lapland.Regional.Environ- ment.Centre,.using.standardised.methods. Data.on.wet.deposition.of.sulphate.and.heavy.metals.was.collected.at.the.meteo- rological.station.of.Oulanka,.situated.in.Kuusamo,.south.from.Salla.and.east.from. Posio..The.deposition.was.measured.once.every.month,.and.the.monthly.values.are. summed.into.annual.deposition.values..Measurements.on.metals.are.available.only. for.the.period.2000–2005.. Fig. 4. Location of the studied lakes and areas of municipalities in northern Finland. Study lakes are marked by red colour, reference lakes by yellow. 10 Lapin ympäristökeskuksen raportteja 5 | 2008 The.SO4.concentrations.were.not.corrected.for.non-marine.values,.because.chloride. was.not.measured.for.many.of.the.sampling.occasions..This.has.no.large.effect.on.the. results,.since.the.marine.influence.(Cl.concentrations).is.low.in.the.studied.area. The.development.of.the.water.quality.(sulphate,.pH,.alkalinity,.Al,.Cu,.Ni).is.first. studied.commonly. for. the.area.of.Salla,.Posio,.Ranua,.Savukoski.and.Sodankylä,. excluding.the.reference.area.and.Inari.municipality,.mostly.for.the.period.1990.to. 2006..Developments.in.the.water.quality.variables.are.presented.as.box-plots.of.the. autumnal.values.of.each.year.. Mean.values.of.sulphate,.alkalinity.and.pH.during.1991–1995.and.1996–2000.are. compared. to. the.period.2001–2005.by.paired.T-tests..After. that,. the.water.quality. in.different.municipality.areas. is. compared,. including. Inari.municipality.and. the. reference.area. 11Lapin ympäristökeskuksen raportteja 5 | 2008 Results Meteorological data The.annual. rainfall. for. the.period.1990–2005. in.Oulanka,.Kuusamo,. is.presented. in.Fig..5..During.the.study.period,.the.amount.of.rainfall.was.higher.than.average. (508.mm/yr).during.years. 1991,. 1992,. 1995,. 1998,. 2000. and.2005..No. significant. difference.was.found.in.the.rainfall.between.the.five-year.periods.1991–1995,.1996–2000,. 2001–2005. The.acidity.of. the.rain.was.highest. in. the.beginning.of. the.observation.period.. pH.below.4.5.was.measured.for.several.months.during.the.year.1990.(Fig..6).. Sulphate.deposition. in.Oulanka.was.at. its.highest. level. in. 1991–1992,. and.has. decreased.to.about.one.third.of.the.maximum.value.after.that.(Fig..7)..The.critical. load.is.estimated.to.be.mostly.20–50.meq/m2/yr.in.the.area,.and.only.for.the.most. sensitive.areas.below.20.meq/m2/yr.(Henriksen.et al..1994)..These.deposition.values. observed,.about.2–6.meq/m2/yr.are.very.unlikely.to.exceed.critical.loads.for.area. Deposition.of.metals. (Cr,.Cu,.Ni). appear. to.have. increased.during.2000–2005,. although.trends.are.not.clear.for.this.short.period.(Fig..8). Fig. 5. Mean annual rain- fall (mm), measured in the sulphate collector at the Oulanka research station.20042002200019981996199419921990 800 600 400 200 0 Rainfall mm 12 Lapin ympäristökeskuksen raportteja 5 | 2008 20042002200019981996199419921990 5,25 5,00 4,75 4,50 4,25 4,00 pH Fig. 6. Annual mean value of monthly measurements of rain water pH at the Oulanka research station. Fig. 8. Annual deposition of chrome, copper and nickel (μg/m2) in rain water at the Oulanka station. Fig. 7. Annual wet sulphate deposition [meq/m2] at the Oulanka station. 20042002200019981996199419921990 8 6 4 2 0 2SO -S meq/m4 200520042003200220012000 160 140 120 100 80 60 40 20 0 µg/m Ni Cu Cr 2 13Lapin ympäristökeskuksen raportteja 5 | 2008 Lake water data The.amount.of.samples.for.each.year.is.reasonably.stable.for.the.period.1990–2006,. except.lower.for.the.years.1990,.2002.and.2006..For.the.area.of.Inari.municipality.in. the.north,.more.affected.by.the.Nikel.smelters,.the.number.of.samples.used.is.also. reasonably.stable,.except.for.the.year.1990.(Fig..9). Low. base. cation. (Ca+Mg+Na+K). concentrations. indicate. sensitivity. to. acid. ification..Concentrations.below.200.μeq/l.are.considered.low,.which.is.the.case.for. most.of.the.study.area..Highest.concentrations.are.found.in.Inari,.and.lowest.in.the. Posio.municipality.(Fig..10)..Note.that.the.number.of.lakes.studied.is.low.for.some. municipalities..(two.lakes.in.Posio.and.one.lake.in.Ranua.and.Savukoski). 20062005200420032002200120001999199819971996199519941993199219911990 30 25 20 15 10 5 0 Number of sites REFERENCEInariSodankyläSavukoskiRanuaPosioSalla Municipality REFERENCE Inari Sodankylä Savukoski Ranua Posio Salla Municipality 400 300 200 100 0 BC Fig. 9. Number of studied lakes for each year, in the municipalities of Salla, Posio, Ranua, Sodan- kylä, Savukoski, Inari, and reference sites. Fig. 10. Base cations [μeq/l] in lake waters in the municipalities of eastern Finnish Lapland, and in the reference area, based on the data from the years 1990–2006. 1 Lapin ympäristökeskuksen raportteja 5 | 2008 Sulphate The.development.of.autumnal.sulphate.concentrations.in.the.lake.waters.in.the.study. area.is.presented.in.Fig..11..Sulphate.concentrations.declined.from.around.30.μeq/l. to.around.20.μeq/l.during.the.1990s..No.more.decline.is.seen.after.the.1990s. The.studied.period.is.divided.into.5-year.periods,.and.the.statistical.significance. of.the.decline.in.the.mean.sulphate.concentrations.is.tested.by.paired.T-tests..The. decline.in.the.sulphate.concentrations.is.statistically.significant.from.1991–1995.to.the. 1996–2000,. but. no. significant. change. from. 1996–2000. to. 2001–2005. is. found. (Table.2). The.trends.in.the.municipalities.are.compared.in.the.Fig..12..Declining.trend.is. seen.for.all.the.sub-areas,.including.reference.area..SO4.concentrations.are.higher.in. the.area.of.Inari,.reflecting.the.influence.of.Nikel/Zapoljarny.smelters. Fig. 11. Autumnal sulphate concentrations [μeq/l] in lake waters: mean values in the combined area of of Salla, Posio, Ranua, Savu- koski and Sodankylä. Fig. 12. Mean autumnal lake water sulphate concentra- tions [μeq/l] in the areas of the municipalities, and in the reference area. 200620042002200019981996199419921990 60 50 40 30 20 10 0 SO eq/lµ4 200620042002200019981996199419921990 60 50 40 30 20 10 0 Mean SO eq/lµ REFERENCEInariSodankylä SavukoskiRanuaPosioSalla Municipality 4 15Lapin ympäristökeskuksen raportteja 5 | 2008 pH Fig. 13. Autumnal pH of the lake waters: mean values in the area of Salla, Po- sio, Ranua, Savukoski and Sodankylä.200620042002200019981996199419921990 8,0 7,0 6,0 5,0 4,0 pH Table 2. Independent samples T-tests for the mean SO4 concentrations, for periods 1991–1995 and 1996–2000 against the period 2001–2005. Fig. 14. Autumnal pH values in different areas: mean values in the lakes of Salla, Posio, Ranua, Savukoski, Sodankylä, Inari and refe- rence area. Note that the first values are from the year 1988. REFERENCEInariSodankylä SavukoskiRanuaPosioSalla Municipality 2006200420022000199819961994199219901988 7,5 7,0 6,5 6,0 5,5 5,0 Mean pH Period Mean SO4 values [μeq/l] Sig. difference to next period 1991–1995 28,7 <0,001 1996–2000 20,7 0,355 2001–2005 19,2 Development.of.the.pH.values.is.presented.in.the.Fig..13..pH.values.have.remained. quite.stable.during.the.study.period..Generally.the.values.are.between.5,5.and.6,5.. A. slight. increase. in. the.mean.pH.value. is. seen. from. the.period.1991–1995. (5.95). to.2001–2005.(6,06),.but.the.increase.is.not.statistically.significant.(Table.3).. The.lowest.pH.values.(<5,0).are.found.in.three.lakes:.one.in.Posio,.one.in.Inari.and. one.in.Sodankylä..The.lowest.measured.value,.4,58,.was.measured.in.Joutolampi,. Sodankylä,.in.1992..The.mean.values.are.low.for.the.municipality.of.Posio,.because. only.two.lakes.were.included.(Fig..14). 16 Lapin ympäristökeskuksen raportteja 5 | 2008 Alkalinity 200620042002200019981996199419921990 200 150 100 50 0 -50 Alkalinity eq/lµ Fig. 15. Autumnal alkalinity [μeq/l] of the lake waters: mean values in the area of Salla, Posio, Ranua, Savukoski and Sodankylä. Alkalinity.value,.or.acid.neutralizing.capacity.(ANC),.of.20.μeq/l.has.been.found.to. be.the.critical.value.for.fish.in.freshwaters.(Henriksen.et al..1990,.1994)..Of.the.studied. lakes,.10.out.of.30.have.mean.alkalinity.value.<20.μeq/l..These.lakes.are.scattered. around.the.study.area,.including.reference.area.. The.autumnal.alkalinity.values.have.increased.from.year.1990.(mean.24.μeq/l).to. the.year.2006.(mean.44.μeq/l.)..Lowest.mean.value.22.μeq/l..is.recorded.for.the.year. 1994,.and.the.highest.mean.value.46.μeq/l.for.the.year.2002.(Fig..15)..The.alkalinity. values.have.increased.more.in.Inari,.than.in.the.other.municipalities.(Fig..16).. The.number.of. lakes.with.alkalinity.below.20.μeq/l.has.decreased.during. the. study.period..In.2006,.all. lakes.in.the.municipalities.of.Ranua,.Savukoski.and.So- dankylä.reached.alkalinity.value.above.20.μeq/l.(Fig..17)..This.more.likely.reflects. the.decreased.acidifying.load.from.western.Europe.than.from.the.Kola.Peninsula,. because.in.three.of.the.four.reference.lakes.alkalinity.also.increased.from.below.to. above.20.μeq/l.. In.table.4,.the.test.results.for.the.differences.in.mean.alkalinity.values.between.the. five-year.periods.is.presented..Mean.alkalinity.value.has.increased,.but.the.increase. is.not.statistically.significant. Table 4. Independent samples T-tests for the mean alkalinity values, for periods 1991–1995 and 1996–2000 against the period 2001–2005. Period Mean alkalinity value [μeq/l] Sig. difference to next period 1991–1995 23,7 0,146 1996–2000 32,7 0,585 2001–2005 36,3 Table 3. Independent samples T-tests for the mean pH values, for periods 1991–1995 and 1996– 2000 against the period 2001–2005. Period Mean pH value Sig. difference to next period 1991–1995 5,95 0,492 1996–2000 6,02 0,676 2001–2005 6,06 17Lapin ympäristökeskuksen raportteja 5 | 2008 20062005200420032002200120001999199819971996199519941993199219911990 20 15 10 5 0 Number of sites REFERENCEInariSodankyläSavukoskiRanuaPosioSalla Municipality Fig. 16. Mean autumnal lake water alkalinity values [μeq/l] in the municipalities, and in the reference area. Note that the observation period starts from the year 1988.200620042002200019981996199419921990 REFERENCEInariSodankylä SavukoskiRanuaPosioSalla Municipality 0,10 0,08 0,06 0,04 0,02 0,00 -0,02 Alkalinity eq/lµ 1988 Fig. 17. Annual number of lakes with autumnal alkalinity value below 20 μeq/l, presented separately for the different municipalities and reference area. Aluminium The.development.of.aluminium.concentrations.annually.is.presented.using.reactive. Al.concentrations,.because.more.valid.measurements.are.available.for.reactive.than. labile.Al..Reactive.aluminium.concentrations.in.the.area.of.Salla,.Posio,.Ranua,.Savu- koski.and.Sodankylä.is.presented.in.Fig..18..The.median.concentrations.were.elevated. in.many.lakes.in.1998–1999.and.in.2006..When.comparing.the.5-year.periods.for.labile. Al,.the.mean.concentration.is.highest.for.the.period.1996–2000,.but.the.differences. are.not.statistically.significant.(Table.5).. 1 Lapin ympäristökeskuksen raportteja 5 | 2008 Mean.labile.aluminium.concentration.in.the.lakes.was.9.μg/l.(range.0–50.μg/l).. According.to.Puro-Tahvanainen.&.Luokkanen.(2007),.in.the.Finnish.northern.Lap- land.lakes.the.mean.labile.Al.concentration.was.8.μg/l,.and.maximum.20.μg/l,.for. the.period.2000–2005. According. to. Wilander. (1999),. concentrations. of. labile. aluminium. over. 25–75.μg/l.are.considered.toxic.for.the.biota..According.to.Verta.et al..(1990),.when. labile.Al. concentration. is. >50. μg/l. and. pH. is. less. than. 5,3,. the. conditions. are. considered.toxic.for.e.g..perch.and.brown.trout..This.was.estimated.to.the.case.for. 7.%.of.lakes.in.Finland.(Verta.et al..1990)..In.this.study.the.maximum.concentration. of.labile.Al.found.was.50.μg/l,.and.so.toxic.effects.of.aluminium.are.unlikely.in.the. study.lakes.at.the.present.concentration.levels. The.aluminium.concentrations.are.dependent.on.the.amount.of.humic.compounds. (total.organic.carbon)..According.to.these.results,.reactive.aluminium.concentrations. appear.to.have.increased.in.the.reference.area,.but.not.in.the.other.areas.(Fig..19).. Labile.Al.mean. concentration.was. significantly.higher.during.1996–2000,. than. in.1991–1995. (Table.5)..This. is.probably.due. to. rainy.years.1998.and.1999,.which. increased.the.amount.of.Al.binding.organic.matter.in.the.waters. 2004200220001998199619941992 200 150 100 50 0 Reactive Al g/lµ MAKIANKALANLAMPI 1 MAKIANKALANLAMPI 1 MAKIANKALANLAMPI 1 Fig. 18. Autumnal reactive aluminium concentrations (μg l-1) in lake water: mean values in the area of Salla, Posio, Ranua, Sakoski and Sodankylä. REFERENCEInariSodankylä SavukoskiRanuaPosioSalla Municipality 2004200220001998199619941992 100 80 60 40 20 0 Reactive Al g/lµ Fig. 19. Mean autumnal reactive aluminum concentrations (μg l-1) in the municipalities of Salla, Posio, Ranua, Sodankylä, Savukoski, and in the reference area. 19Lapin ympäristökeskuksen raportteja 5 | 2008 Copper Copper.concentrations.have.been.below.1.μg/l,.with.the.exception.of.one.measure- ment.in.Nuottalampi.in.1996.(Fig..20)..According.to.Alm.et al..(1999),.concentrations. below.3.μg/l.cause.little.risk.for.toxic.effects..Limit.for.acceptable.concentration.in. EU.is.5.μg/l.(Alm.et al..1999). The.copper.concentrations.appear.to.have.increased.during.the.study.period.in. Inari. (Fig..21).. In.other.municipalities.no.trends.are. found.(Table.6)..Median.con- centration.in.the.reference.lakes.is.0,15.μg/l..No.significant.changes.in.the.copper. concentration.are.found.between.the.5-year.periods.(Table.6). 2006200520022001199619951992 1,50 1,00 0,50 0,00 Cu g/lµ NUOTTALAMPI 317 HANKARIMPILAMPI 438 NUOTTALAMPI 317 NUOTTALAMPI 317 Fig. 20. Development of copper concentrations (μg l-1) in the lake waters: autumnal mean values in the area of Salla, Posio, Ranua, Savukoski and Sodankylä. Period Mean labile Al [μg/l] Sig. difference to next period 1991–1995 6,25 0,005 1996–2000 11,80 0,080 2001–2005 8,10 Table 5. Independent samples T-tests for the mean labile aluminium values, for periods 1991–1995 and 1996–2000 against the period 2001–2005. Fig. 21. Mean autumnal cop- per concentrations (μg l-1) in the lakes of the municipalities of Salla, Posio, Ranua, Sodan- kylä, Savukoski, Inari, and in the reference area. REFERENCEInariSodankylä SavukoskiRanuaPosioSalla Municipality 200420022001199619951992 1,0 0,8 0,6 0,4 0,2 0,0 Cu g/lµ 20062003 2005 20 Lapin ympäristökeskuksen raportteja 5 | 2008 2006200520022001199619951992 1,50 1,00 0,50 0,00 2,00 Ni g/lµ ARVOLAMPI S3 SIURULAMPI R228 SUOPALAMPI 1 HANKARIMPILAMPI 438 Fig. 22. Development of nickel concentrations (μg l-1) in the lake waters: autumnal mean values in the area of Salla, Posio, Ranua, Savukoski and Sodankylä. Table 6. Independent samples T-tests for the mean copper concentrations, for periods 1991–1995 and 1996–2000 against the period 2001–2005. Period Mean Cu [μg/l] Sig. difference to next period 1991–1995 0,33 0,235 1996–2000 0,45 0,324 2001–2005 0,34 REFERENCEInariSodankylä SavukoskiRanuaPosioSalla Municipality 200420022001199619951992 20062003 2005 1,0 0,5 0,0 Ni g/lµ Fig. 23. Development of nickel concentrations (μg l-1) in the lakes: autumnal mean values in the municipalities of Salla, Posio, Ranua, Sodankylä, Savukoski, Inari, and in the reference area. Nickel Nickel.concentrations.have.been.below.1.μg/l,.except.in.2001.in.some.of.the.lakes.(Fig.. 22)..These.lakes.are.mostly.in.the.area.of.Inari,.where.the.nickel.concentrations,.as. well.as.copper.concentrations,.have.increased.after.1996.(Fig..23)..The.concentrations. are.still.fairly.low:.concentrations.more.than.15.μg/l.are.measured.closer.to.the.Nikel. smelters.(Puro-Tahvanainen.&.Luokkanen.2007),.and.concentrations.below.15.μg/l. are.considered.to.indicate.low.risk.for.biological.effects.(Alm.et al..1999). The.mean.nickel.concentration.have.not.changed.considerable.during.the.study. period..Lowest.mean.concentrations.are.recorded.for.the.late.1990’s.(Table.7). 21Lapin ympäristökeskuksen raportteja 5 | 2008 Table 7. Independent samples T-tests for the mean nickel concentrations, for periods 1991–1995 and 1996–2000 against the period 2001–2005. Period Mean Ni [μg/l] Sig. difference to next period 1991–1995 0,25 0,125 1996–2000 0,17 0,109 2001–2005 0,28 Table 8. Median concentrations of some metals (μg/l) in the studied lakes in Salla, Posio, Ranua, Savukoski and Sodankylä, median values in the reference lakes, and in northern Finland according to Mannio (2001). Metal 1991–1995 1996–2000 2001–2005 Reference Mannio (2001) As 0,18 0,16 0,14 0,09 0,17 Cd 0,01 0,06 0,02 0,02 0,02 Cr 0,29 0,24 0,31 0,11 0,24 Pb 0,26 0,23 0,15 0,08 0,25 Zn 1,90 1,35 1,30 1,00 1,84 Other metals Table.8.lists.mean.and.maximum.concentrations.of.arsenic,.cadmium,.chrome,.lead. and.zink.in.the.study.area,.together.with.the.median.values.in.the.reference.area.and. in.northern.Finland.according.to.Mannio.(2001).. Alm.et al. (1999).created.a.classification.system.for.biological.effects.associated.with. the.metal.concentrations:.class.1.=.no.or.very.small.risk;.class.2.=.small.risk;.3.=.some. biological.effects.are.possible;.class.4–5.=.elevated.risk..The.median.arsenic,.zink,. copper.and.nickel.concentrations.for.all.the.5-year.periods.indicate.class.1.conditions.. Median.chrome.concentration.indicate.class.1.conditions.for.the.period.1991–2000,. and.class.2.conditions.for.the.period.2001–2005..Lead.concentrations.indicate.class. 2.conditions.for.1991–2000.,.and.class.1.conditions.for.2001–2005..Cadmium.is.the. only.one.of.the.metals,.for.which.the.concentrations.indicate.class.2.conditions.for. the.whole.study.period. 22 Lapin ympäristökeskuksen raportteja 5 | 2008 Discussion The.concentrations.and.trends.of.sulphate.and.metals.in.the.lakes.in.eastern.Lapland. (south.of.Inari).are.close.to.the.concentrations.and.trends.seen.in.the.reference.lakes,. with.the.exception.of.elevated.nickel.concentrations.in.the.lakes.of.Salla.in.2006..Aci- dification.is.not.detected.in.the.area,.after.the.acidification.trend.to.the.early.1990’s,. and.recovery.during.the.late.1990’s. Background.non-marine.sulphate.concentration.for.dilute.lakes.is.estimated.to.be. 15.μeq/l.(Brakke.et al..1989)..At.the.time.of.higher.sulphate.emissions.in.the.1980’s,. median.sulphate.concentration. in.northern.Finland.was.estimated. to.be.35.μeq/l. (Forsius.et al..1990)..Mean.sulphate.concentration.in.the.lakes.studied.here,.excluding. the.area.of.Inari,.decreased.from.29.μeq/l.during.1991–1995.to.19.μeq/l.in.the.period. 2001–2005,.which.is.near.the.estimated.background.level..In.Inari,.area.of.Raja-Joo- seppi.closer.to.the.Pechenganickel.smelters,.the.sulphate.concentrations.are.higher,. around.30–40.μg/l. According.to.the.announced.emissions.from.the.Monchegorsk.during.1990–2002,. the.sulphate.emissions.were.at.their.highest.in.the.year.1990,.after.which.they.dec- reased.to.their.present.level.by.the.year.1999..The.wet.deposition.in.Oulanka,.Kuu- samo,.peaked.in.1991–1992..The.emissions.and.deposition.levels.do.not.correspond. at.the.annual.level,.but.the.trends.are.similar:.decline.during.the.1990’s,.and.steady. levels.after.that..Annual.rainfall.measurement.partly.explains.the.deposition.data:. SO4.levels.are.elevated.for.the.years.with.rainfall.higher.than.usual. The.mean.concentration.of.SO4.in.the.lake.waters.reached.it.maximum.in.1991,. and.has.decreased.since..The.concentrations.follow.the.decline.in.the.emissions.from. Monchegorsk. The.rain.was.most.acidic.in.the.year.1990.in.Oulanka,.but.the.acidification.is.seen. only.after.some.delay.in.1992.in.the.lake.waters.in.Salla..The.delay.can.be.explained,. at.least.partly,.by.the.higher.level.of.leaching.of.base.cations.from.the.catchments.to. the.lakes.during.1989–1991.(Fig..24). The.lakes.recovered.from.the.acidification.during.the.mid-.or.late.1990’s,.as.could. be.expected.from.the.decreased.levels.of.acid.deposition..The.amount.of.lakes.with. alkalinity.below.20.μeq/l.has.been.at.the.pre-acidification.level.after.the.year.1996.. Almost.all.sulphate.concentrations.measured.are.far.below.values.that.would.cause. acidification.in.the.lakes.. Also.the.AMAP.report.(AMAP.2006).indicates.decreasing.or.flat.trends.for.sulphate. concentrations. in.air. for.all.monitoring. sites.after. the.1980s.. In. Jäniskoski,.howe- ver,.total.sulphate.concentration.in.air.was.elevated.from.long-term.values.below. 0,5.μg/m3.to.about.0,8.μg/m3.during.summer.2003,.which.is.the.last.value.presented. in.the.AMAP.report. Sulphate. concentrations.decreased. in. the.1990s.not.only. in. the. study.area.but. allover.northern.arctic. (Canada,.Svalbard,.Fennoscandia.and.NW.Russia;.AMAP,. 2006)..This.decreasing.trend.is.seen.also.in.the.reference.sites..This.leads.to.conclusion,. 23Lapin ympäristökeskuksen raportteja 5 | 2008 200520032001199919971995199319911989 150 100 50 0 BC Fig. 24. Concentration of base cations (μeq/l) in the lakes of Salla, Posio, Ranua, Savukoski and Sodankylä during the period 1989–2006. that.the.increased.alkalinity.in.the.studied.lakes.is.at.least.partly.due.to.the.decreased. deposition.from.the.western.Europe.. One.should.notice.that,.according.to.Kämäri.(1998).around.75.%.of.the.deposition. of.acidifying.compounds.could.occur.in.the.form.of.dry.deposition,.which.should.also. be.monitored..Model.predictions,.based.on.full.implementation.of.the.agreements. made.so.far,.indicate.that.the.decreasing.trend.in.sulphate.deposition.is.like.to.level. off.after.2010.(AMAP,.2006). Data.on.the.deposition.of.metals.and.their.concentrations.in.lakes.is.much.more. sparse.than.the.data.on.sulphate.and.acidification..Generally,.no.clear.trends.are.seen. in.the.concentrations.of.metals.in.the.lake.waters..The.copper.and.nickel.values.are. far.below.safe.limits.(3.and.15.μg.l-1,.respectively). Weak.increasing.trend.in.the.copper.and.nickel.is.seen.in.Inari,.where.also.Puro- Tahvanainen.&.Luokkanen.(2007).observed.the.same.increasing.trend.(area.of.Raja- Jooseppi,.south.of.Lake.Inari)..This.trend.is.probably.due.to.the.smelters.in.Nikel,.but. increased.concentration.of.nickel.is.seen.also.in.the.lakes.of.Salla.in.2006,.and.there. is.some.increases.in.the.deposition.of.metals.in.Kuusamo.(Oulanka.station).during. the.period.2000–2005... North.Atlantic.Oscillation. (NAO).affects. the. long-range. transport.of.pollutants. from.Europe,.North.America.and.Asia.to.the.arctic..The.NAO.index.was.strongly. positive.during.1990–1995,.which.increased.the.deposition.of.pollutants.in.the.arctic.. During.1996–1999.the.NAO.index.was.negative,.not.favouring.the.long-term.transport. of.pollutants.to.the.arctic..Climate.models.predict.that.the.frequency.of.positive.phases. is.likely.to.increase.in.the.near.future.(AMAP,.2006).. The.influence.of.the.NAO.must.be.considered.in.any.studies.on.trends.in.arctic. pollution. (AMAP,.2006)..This. climate.phenomenon.probably. explains.part.of. the. decreasing.trend.seen.in.the.sulphate.deposition.in.the.Finnish.Lapland.during.the. 1990s. 2 Lapin ympäristökeskuksen raportteja 5 | 2008 Recommendations.for.future. monitoring Monitoring.should.be.carried.out.southwest.from.the.Montshegorsk.industrial.comp- lex.(ie..in.the.municipalities.of..Salla.and.Kuusamo,.because.they.are.still.at.the.risk. for.high.fall-out.events.from.Montshegorsk..Also.other.areas.sensitive.to.acidification. should.be.monitored..These.are.areas.with.low.buffering.capacity,.caused.by.the.hard. bedrocks. Small.headwater. lakes.and.rivers.are.considered. the.most. sensitive. freshwater. systems,.that.should.be.monitored.for.acidification..A.spatially.covering.net.of.sites,. and.in.addition.a.small.number.of.frequently.monitored.sites.is.recommended.for. effective.monitoring.of.the.acidification.trends.. Biological.methods.(periphyton.and.fauna).are.recommended.for.running.waters.. Water.quality.in.running.waters.is.very.variable,.which.makes.the.chemical.moni- toring.of.the.water.quality.problematic..Biological.methods.overcome.this.problem,. collecting.information.from.the.whole.growing.season. Sampling.during.autumnal.overturn.in.the.lakes.best.reflects.the.general.water. quality.in.the.lakes.(Mannio,.2001)..Episodic.acidifying.events.(high.sulphate.deposi- tion,.spring.snow.melt).need.to.be.studied.by.frequent.sampling.(days-weeks).and/or. biological.methods.in.selected.sites.with.low.buffering.capacity..Sampling.of.biota. suits.well.the.needs.of.detecting.the.effects.of.the.episodic.events,.and.so.the.amount. of.biological.sampling.(benthic.fauna,.fish).should.be.increased.also.for.lakes.. 25Lapin ympäristökeskuksen raportteja 5 | 2008 REFERENCES Alm.G,.Tröjbom.M,.Borg.H,.Göthberg.A,.Johansson.K,.Lindeström.L.&.Lithner.G.(1999).Metaller..In:. Wiederholm.T.(ed.).Bedömningsgrunder.för.miljökvalitet..Sjöar.och.vattendrag..Naturvårdsverket Rapport 4920:.109-172. AMAP.assessment.(2006).Acidifying pollutants, Arctic Haze, and Acidification in the Arctic..Arctic.Monito- ring.and.Assessment.Programme.(AMAP),.Oslo,.Norway..xii.+.112.pp. Brakke.DF,.Henriksen.A,.Norton.SA.(1989).Estimated.background.concentrations.of.sulphate.in.dilute. lakes..Water Resour. Bull. 25:.247–253. Finnish.Meteorological.Institute.(1991) Climatological Statistics in Finland.1961-1990..Helsinki..ISBN.951- 697-355-8..125.p. Forsius.M,.Kämäri.J,.Kortelainen.P,.Mannio.J,.Verta.M.&.Kinnunen.K.(1990).In:.Kauppila.P,.Anttila.P. &.Kenttämies.K.(eds.),.Acidification in Finland..Finnish.Acidification.Research.Programme.HAPRO. 1985–1990,.pp..759–780..Springer-Verlag,.Berlin. Henriksen.A,.Kämäri.J,.Poach.M,.Lövblad.G,.Forsius.M.&.Wilander.A.(1990).Critical.loads.to.surface. waters.in.Fennoscandia..Nordic.Council.of.Ministers..Miljørapport.1990:124. 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Miettinen Title of publication Effects of the Kola Air Pollution Sources in Finnish Lapland Surface Waters during 1990–2006 Publication series and number Lapin ympäristökeskuksen raportteja 5/2008 Theme of publication Parts of publication/ other project publications www.ymparisto.fi/lap/julkaisut Abstract This study presents water quality data for 30 small lakes in Finnish Lapland during 1990–2006. The presentation is concentrated on the southeastern Finnish Lapland (municipalities of Salla, Posio, Ranua, Savukoski, Sodankylä), and the results are compared to the results in the most northern Lapland (Inari municipality). Sulphate emissions from the Kola Peninsula, as well as deposition of sulphate in Lapland declined in the 1990’s. In consequence, the number of lakes with measured alkalinity below critical level (20 μeq/l) declined in Finnish Lapland to near pre-acidification level. Sulphate concentrations in lake waters declined along with the deposition in the 1990’s. No further decline in the concentrations are detected after the year 2000. Metal concentrations in the lakes do not follow any clear trends in the study area, except for the slightly elevated nickel concentrations in Inari and Salla municipalities. However, mean copper and nickel concentrations are far to near pre-acidification level. Based on the results, monitoring of sulphate and metal concentrations is recommended to be continued for the easternmost areas in Salla and Inari. Biological methods (diatoms, zoobenthos) would enhance the early detec- tion of possible acidification in surface waters in the future. Keywords acidification, Kola Peninsula, Lapland, lakes, Monchegorsk, metals, sulphate, surface waters Financier/ commissioner Lapland Regional Environment Centre ISBN 978-952-11-3148-6(pbk.) ISBN 978-952-11-3149-3(PDF) ISSN 1796-1971 (print) ISSN 1796-198X (online) No. of pages 27 Language english Restrictions Public Price (incl. tax 8 %) For sale at/ distributor Lapin ympäristökeskus P.O. Box 8060, FIN-96101 ROVANIEMI Phone +358 20 690 173, e-mail: kirjaamo.lap@ymparisto.fi Financier of publication Lapland Regional Environment Centre Printing place and year Helsinki University Print, Helsinki 2008 27Lapin ympäristökeskuksen raportteja 5 | 2008 KUVAILULEHTI Julkaisija Lapin ympäristökeskus Julkaisuaika kesäkuu 2008 Tekijä(t) Juha O. Miettinen Julkaisun nimi Kuolan niemimaan ilmansaasteiden laskeuman vaikutukset vesistöihin Suomen Lapissa1990–2006 (Effects of the Kola Air Pollution Sources in Finnish Lapland Surface Waters during 1990–2006) Julkaisusarjan nimi ja numero Lapin ympäristökeskuksen raportteja 5/2008 Julkaisun teema Julkaisun osat/ muut saman projektin tuottamat julkaisut www.ymparisto.fi/lap/julkaisut Tiivistelmä Tutkimus selvitti vedenlaadun muutoksia Lapin pienissä järvissä. Tulosten esittely keskittyy Kaakkois-Lappiin (Sallan, Posion, Ranuan, Sodankylän ja Savukosken kunnat), ja tuloksia verrataan pohjoisempaan Inarin itäosien alueeseen. Sulfaattipäästöt Kuolan metallisulattamoista, ja myös sulfaatin laskeuma Itä-Lappiin, pienenivät 1990-luvun aikana. Laskeuman vähenemistä on seurannut myönteinen kehitys järvien happamoitumistilanteessa: järvien, joiden alkali- niteetti on ollut alle kriittisen rajan (20 μeq/l), määrä on vähentynyt lähelle happamoitumista edeltänyttä tasoa Sulfaattipitoisuudet pienissä järvissä vähenivät laskeuman pienenemisen myötä 1990-luvulla. 2000-luvulla sulfaattip- itoisuudet eivät ole enää pienentyneet. Järvien metallipitoisuuksissa ei ole nähtävissä selkeitä trendejä, paitsi hieman kohonneet nikkelipitoisuudet Inarin ja Sallan alueilla. Keskimääräiset kupari- ja nikkelipitoisuudet ovat kuitenkin lähelle happamoitumista edellyttänyttä tasoa. Tulosten perusteella sulfaatti- ja metallipitoisuuksien seurantaa tulisi jatkaa erityisesti itäisimmillä Sallan ja Inarin alueilla. Biologisten menetelmien (piilevät, pohjaeläimet) käyttö seurannoissa parantaisi mahdollisten pintavesien happamoitumisongelmien nopeaa havaitsemista tulevaisuudessa. Asiasanat happamoituminen, järvet, Kuolan niemimaa, Lappi, metallit, Montshegorsk, pintavedet, sulfaatti Rahoittaja/ toimeksiantaja Lapin ympäristökeskus ISBN 978-952-11-3148-6 (nid.) ISBN 978-952-11-3149-3 (PDF) ISSN 1796-1971(pain.) ISSN 1796-198X(verkkoj.) Sivuja 27 Kieli englanti Luottamuksellisuus julkinen Hinta (sis.alv 8 %) Julkaisun myynti/ jakaja Lapin ympäristökeskus PL 8060, 96101 ROVANIEMI Puh. 020 690 173, sähköposti: kirjaamo.lap@ymparisto.fi Julkaisun kustantaja Lapin ympäristökeskus Painopaikka ja -aika Yliopistopaino, Helsinki 2008 Lapin ympäristökeskus LAPIN YMPÄRISTÖKESKUKSEN RAPORTTEJA 5 | 2008 ISBN 978-952-11-3148-6 (nid.) ISBN 978-952-11-3149-3 (PDF) ISSN 1796-1971 (pain.) ISSN 1796-198X (verkkoj.) L A P IN Y M P Ä R IS T Ö K E S K U S Lapin ympäristökeskus PL 8060 96101 ROVANIEMI Puh. 020 690 173 As part of the larger project “The effects of the Kola air pollution sources in the areas of the Kola Peninsula and Finnish Lapland”, this study presents water quality data for 30 small lakes in Finnish Lapland during 1990–2006. From 1990 to 2003, sulphur emissions decreased 68 % and 82 % at Nikel and Monchegorsk, respectively. During the same period, the number of lakes with measured alkalinity below critical level (20 μeq/l) have declined in Finnish Lapland close to pre-acidi cation level. Effects of the Kola Air Pollution Sources in Finnish Lapland Surface Waters during 1990–2006 Juha O. Miettinen E F F E C T O F T H E K O L A A IR P O L L U T IO N S O U R C E S IN F IN N IS H L A P L A N D S U R F A C E W A T E R S D U R IN G 1 9 9 0 — 2 0 0 6 LAPIN YMPÄRISTÖKESKUS