d-Sf #807/4*3 - /V6 KEM Bses No 1/98 received JUS 2 919% OST l Cadmium exposure in the Swedish environment FOREIGN sales PROHIBITED Exemption Substances Project THE SWEDISH NATIONAL CHEMICALS INSPECTORATE DISCLAIMER Portions of this document may be illegible electronic image products. Images are produced from the best available original document. Cadmium exposure in the Swedish environment Part I Cadmium in Sweden - environmental risks Part II Cadmium in goods - contribution to environmental exposure Part III Cadmium in fertilizers, soil, crops and foods - the Swedish situation ISSN: 0284-1185 Order No. 360 598 Printed by: Printgraf, Stockholm, March 1998 Publisher: Swedish National Chemicals Inspectorate© Order address: P.O. Box 1384, S-171 27 Solna, Sweden Telefax 46 8-735 52 29, e-mail [email protected] Part I Cadmium in Sweden - environmental risks Helena Parkman and Ake Iverfeldt, Swedish Environmental Research Institute, Hans Borg and Goran Lithner, Institute for Applied Environmental Research - Laboratory for Aquatic Environmental Chemistry Contents Summary $ Sammanfattning 8 1. Introduction 11 2. Naturally occurring cadmium 12 2.1. Background concentrations in Sweden 12 3. Sensitivity in the Swedish environment 15 3.1 Poor soils and sensitivity to acidification 16 3.2 The Baltic Sea, something between a lake and a sea 19 4. Cadmium in air 20 4.1 Concentrations 20 4.2 Deposition 21 5. Cadmium in terrestrial ecosystems 23 5.1 Concentrations and mobility 23 5.1.1 Forest soil 23 5.1.2 Agricultural soils 27 5.2 Accumulation in and effects on soil organisms 29 5.3 Accumulation and effects in higher terrestrial organisms 31 5.4 Accumulation and effects in plants 35 5.5 Conclusions - effects in the terrestrial environment 37 6. Cadmium in aquatic ecosystems 38 6.1 Concentrations 39 6.1.1 Rivers and lakes 40 6.1.2 Groundwater 45 6.1.3 Seas 45 6.2 Accumulation in, and effects on aquatic organisms 48 6.2.1 Factors affecting bioaccumulation and effects 48 6.2.2 Effects on aquatic organisms 53 6.1.4 Effect studies on organisms captured in Swedish environments 55 6.3 Conclusions- effects of cadmium in Swedish aquatic environments 56 7. Cadmium in the Urban environment 57 8. Temporal trends 60 9. Overall conclusions 64 10. References 68 10.1 Personal communications 76 11. Appendix n Summary The present report aims at assessing possible effects of cadmium in the Swedish environment. Swedish soils and soft freshwater systems are, due to a generally poor buff ­ ering capacity, severely affected by acidification. In addition, the low salin­ ity in the Baltic Sea imply a naturally poor organism structure, with some important organisms living close to their limit of physiological tolerance. Cadmium in soil is mobilised at low pH, and the availability and toxicity of cadmium in marine systems are enhanced at low salinity. The Swedish envi­ ronment is therefore extra vulnerable to cadmium pollution. The average concentrations of cadmium in the forest mor layers, agricul­ tural soils, and freshwaters in Sweden are enhanced compared to ‘back­ ground concentrations ’, with a general increasing trend from the north to the south-west, indicating strong impact of atmospheric deposition of cadmium originating from the central parts of Europe. In Swedish sea water, total cadmium concentrations, and the fraction of bioavailable ‘free’ cadmium, generally increases with decreasing salinity. Decreased emissions of cadmium to the environment have led to decreasing atmospheric deposition during the last decade. The net accumulation of cadmium in the forest mor layer has stopped, and even started to decrease. In northern Sweden, this is due to the decreased deposition, but in southern Sweden the main reason is increased leakage of cadmium from the topsoil ’s as a consequence of acidification. As a result, cadmium in the Swedish environments is undergoing an extended redistribution between different soil compartments, and from the soils to the aquatic systems. Cadmium concentrations measured in surface layers of forest soils and peatlands (up to 2 mg Cd kg"' dw) in southern Sweden are close to critical concentrations at which effects on microbiological activity occur. Measured concentrations in soil solution and data on toxicity to microorganisms in water indicate that cadmium concentrations in forest soil pore water may reach hazardous concentrations. When calculating the risk for effects according to the EU Technical Guidance Document, it is indicated that also the concentrations measured in Swedish agricultural soils might affect soil living organisms. There is some evidence for chronic effects (kidney dysfunction) in certain mammals (bank voles) close to a point source in northern Sweden. 5 The effects occur at kidney cadmium concentrations > 4 mg Cd kg'* wet weight. Kidney cadmium concentrations above this level have also been found in a considerable number of bank voles captured in southern Sweden, indicating that these animals might suffer from kidney dysfunction as well, due to accumulation of cadmium from diffuse sources. Some plants in Sweden, especially certain trees, accumulate cadmium to concentrations that might be hazardous to the plants themselves and maybe also to birds and herbivorous mammals feeding on them. Lakes in southern Sweden are severely damaged by acidification and many species have disappeared. Since both the total concentrations and the amount of free (ionic) cadmium, increases at low pH, chronic effects of cadmium may add to other effects caused by the acidification. Cadmium concentrations in a large number of the acidified lakes in southern Sweden, exceed the reported LOEC (0.17 pg Cd L*l) for freshwater organisms, and can reach concentrations >0.3 pg Cd L" 1. Concentrations in acidified rivers are mostly below 0.1 pg L" 1. The Baltic Sea is severely affected by many different pollutants. The eu­ trophication, with large areas of the bottom being anoxic as a result, is probably the most harmful factor to the biota. However, the effects of dif­ ferent stress factors often add to each other. Therefore, the cadmium in the Baltic Sea may imply extra stress for certain organisms. Organisms in the seas surrounding Sweden accumulates more cadmium at lower salinity, and the concentrations in certain organisms (e.g. Baltic Herring) are also in ­ creasing over time. Cadmium concentrations in water of the Swedish seas (0.02-0.05 pg L" *) do not exceed reported LOECs, while LOECs for sedi­ ment-dwelling organisms are exceeded in certain areas of the Baltic Proper. Generally, the diffuse contamination of cadmium in urban soils is not re­ markably high, e.g. concentrations in parks in Stockholm usually represent an enhancement less than four times the average concentration in Swedish agricultural soils. Still effects on biota may occur in certain areas.In indus­ trial areas, the concentrations in soil is sometimes markedly enhanced, e.g. > 30 times in the areas around the RonnsMrsverken smelters. Such high concentrations may affect soil organisms, and the uptake in plants. Accumu­ lation in plants may cause risks for both the plants themselves, as well as for birds and mammals feeding on them. Little is known about the long-term effects of cadmium leakage from old landfills, as well as from those in use. 6 More than 23 tonnes of cadmium is annually deposited on landfills in Sweden today. About 1 % of this amount leaches to ground and surface waters. Water bodies in urban areas are often highly disturbed and also enriched with cadmium, to concentrations exceeding LOECs for aquatic organisms. However, it is impossible to distinguish effects of cadmium from the effects of other pollutants, and disturbing factors, prevailing in these environments. All inputs of cadmium, through atmospheric deposition, with fertilisers, with sludge or as diffuse leakage from articles of consumption, will put extra pressure on the Swedish environment, and should therefore be avoided. 7 Sammanfattning Foreliggande rapport syftar till att sammanfatta tillstandet i den svenska miljon, med avseende pa forekomst och effekter av kadmium. Framst tva faktorer gor den svenska miljon speciellt kanslig for extra till- skott av kadmium. Dels innebar berggrundens laga vittringshastighet i Sverige att manga sjoar bar ultramjukt vatten och att de fiesta jordama bar lag buffertkapacitet. Detta medfbr att den pagaende forsumingen av mark och vatten i Sverige dkar mobiliteten av kadmium, samt att mark- och vat- tenlevande organismer redan paverkas av forsumingen och darmed &r min- dre toleranta for kadmiumexponering. Dels medfbr den laga salthalten i Ostersjdn att ekosystemet ar utarmat och att manga organismer lever nara sin fysiologiska toleransniva, samt att biotillgangligheten av kadmium ar hogre jamfort med i rent marina system. Uppmatta halter av kadmium i skogsmark, akerjord och sotvatten ar forhojda i forhallande till bakgrundsvarden, med en generell trend av okande halter fran norr till sydvast. Detta visar pa stark paverkan fran deposition av lufttransporterat kadmium, och forsurande amnen fran Mel- laneuropa. I sydvastra Sverige ar haltema forhojda 6-8 ganger i skogsmark- ens marlager, och upp till 30 ganger i de sura sjoamas vatten (pH runt 4.5), jamfort med de generella bakgrundsvardena (0.17 mg Cd kg" Us respektive 0.01 p.g Cd L"l). I de svenska havsomradena okar kadmiumhalten generellt med minskande salthalt. Begransningar av kadmiumutslapp till miljon har medfort att depositionen av kadmium i Sverige har minskat med ca 50 % under de senaste tva artion- dena. Netto-ackumulationen av kadmium i skogens marlager har upphort i de fiesta omraden i Sverige. I de nordligaste delama ar detta troligen en direkt effekt av den minskade depositionen, medan den huvudsakliga or- saken till detta i sodra Sveriga, ar att forsumingen har medfort ett okat utlackage av kadmium fran markens bvre skikt. Pa grund av forsumingen pagar for narvarande en omfattande omfordelning av kadmium, fran mark­ ens ytskikt till djupare jordlager och sa smaningom till avrinningsvatten och sjoar. Detta aterspeglas i forhojda kadmiumhalter i sma backar och sura sjoar i sodra Sverige.