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Ontario MinistryoftheEnvironmentprogramsandinitiatives Cobalt in the environment Cobaltisanelementthatoccurs naturally throughout theworld is8 parts permillion in many differentchemical forms (ppm). In Ontario, backgroundcobaltcon- throughoutourenvironment. Small centrations in old urban parkland can reach amounts ofcobaltareessential forgood an upper limitof17 ppm. Concentrations health. Itisa natural earth elementand is in rural parkland can reach 16 ppm. Cobalt present in traceamounts in soil, plantsand concentrations insoilsaround Ontario mine Cobaltisanatural in our diets. In pureform it isasteel-grey sites have been reported as highas6,450 earthelementpresent sionilt,rpalceanatmsoaunndtsininour tCnooubmbalblaetcrkIIsoafhniodnrygCahonabiracdltamneIIdtI,ailwnhoirIcgthaanlfiscoorsemaxlitasst.sas opcpcmTuo.rxibceelfofwecstosiloncobpalalnttscoanrceenutnrlaikteiloynstoof diets. Itusuallyoccurs Cobaltusually occurs inassociation with 40ppm. However, concentration in thesoil inassociation with othermetalssuch ascopper, nickel, man- is notthe onlyfactordeterminingtoxicity. othermetalssuch ganeseand arsenic. Small amountsare Plantspeciesvary in theirsensitivityto ascopper, nickel, found in mostrocks, soil, surfaceand under- cobalt, and soil typeand soilchemistry manganeseand groundwater, plantsand animals. greatly influencecobalttoxicity. Oneofthe arsenic. Natural sources ofcobaltin theenviron- mostimportantsoil properties issoil acidity. mentaresoil, dust, seawater, volcanic The moreacidicthesoil, the greaterthe eruptionsandforestfires. It isalso released potential forcobalttoxicity, atanyconcen- totheenvironmentfrom burning coaland tration. Cobaltisrarelythecontaminantof oil, from car, truckandairplaneexhausts, greatestconcernatcontaminated sitesin and from industrial processesthatuse the Ontario, since ithasrelatively lowtoxicity. metal or itscompounds. Soilswith high cobaltconcentrationsusually Cobaltand itssaltsareused inavariety also have higharsenicand, nickel concentra- — ofprocesses to makesuperalloyswhich tionsand theseelementsare generallymore maintain theirstrength at high temperatures; toxicto plantsand humansthancobalt. asa paintdrier; asa ground coatforporce- lain enamelingused onsteel bathroom Is cobalt harmful? fixturesand large appliances; andasan Cobaltisessential in traceamountsfor ingredientofcoloured pigments. human life. Itispartofvitamin B-12, and Someradioactive isotopesofcobalt, such playsa keyrole in the body'ssynthesisofthis asCobalt 60, areused in treating patients in essential vitamin. Cobalthasalso been used nuclearmedicineand in research. asatreatmentforanemia, because itcauses Natural cobaltcan stay intheairfora few red blood cellsto be produced. days, but itwill stayforyears in waterand Thetoxicityofcobalt isquite low soil. compared to manyothermetalsinsoil. Exposuretovery high levelsofcobaltcan How much cobalt is there cause healtheffects. Effectsonthe lungs, usually in our soil? including asthma, pneumonia, and wheez- All soil containssomeamountofcobalt. ing, have been found inworkerswho Theaverage concentration ofcobaltinsoils breathed high levelsofcobalt in theair. Ministryofthe Environment PactSheet In the 1960s, some breweriesadded cobalt areveryhigh, theamountofcobalt in local to beertostabilizethefoam. Some people gardensoils hasbeen found to bejustabove whodrank large quantities ofthe beerexpe- background concentrations. This is because rienced nausea, vomiting, and seriouseffects gardensoilsare often deeplycultivated, on theheart. However, effects on the heart which mixescontaminated surfacesoil with have not been seen in peoplewithanemia often cleanersubsoil, and improved through orpregnantwomen medicallytreated with theaddition ofclean soil, manure, compost, cobalt. Animal studies havefound problems peat mossand othersoil conditioners. with the development ofthefetus in animals Sampling ofgardenvegetables in areas exposed to high concentrations ofcobalt with soilcobaltconcentrations ofupto 28 during pregnancy. However, cobalt isalso ppm found the highestcobaltconcentrations essential forthegrowthand development in planttissueto be 11ppm in beetroots ofcertain animals. and 4 ppm in beettops. These tissuecon- The International Agencyfor Research centrationsarewell belowtheconcentrations on Cancer hasdetermined thatcobalt isa of25-100 ppmthatareconsidered the possible carcinogen to humans. Studiesin threshold fortoxicity in plants. animalshaveshown thatcobaltcausescan- cerwhen placed directly intothe muscle or Who is at risk? undertheskin. Cobaltdid notcausecancer Elementalcobalt poses norecognized health in animals thatwereexposed to itin theair, hazard to peoplewhoareexposed tolow in food, or in drinkingwater. Cobaltand levelsin food ortheenvironment. Exposures cancerstudieson peopleare inconclusive. forchildren will tend to be higherthan for adults becausechildren havesmaller body How does exposure to cobalt weights. Nospecialagegroups have been occur? identified as beingsensitiveto theeffectsof Everyone in theworld isexposed toat low cobaltand adverseeffects have beenseen levelsinair, water, and food. Estimatesof only inadults. exposure forcobaltsuggestthattypically morethan 99 percent isthrough thefood What can you do to reduce weeateveryday. Exposurethrough drinking exposure to cobalt in soil? water, airand soil contact isconsidered very Nospecial measuresare needed toreduce small. exposure toenvironmental cobaltto people, Higherexposurescan occurforworkers buta person can takesimple stepstoreduce whoareexposed tocobalt in industriesthat exposure, iftheywish to. Thesestepsapply processitormake products containing toreducingexposurestoanymetal in soil in cobalt. anylocation. Wherecobaltconcentrationsin soil are Can cobalt exposure occur greaterthan 40 ppm, andcobalttoxicityto through eating backyard vegetation issuspected, cobaltuptake into vegetables? plantscan be reduced by limingthesoil and It isunlikelythateating backyard vegetables byincorporating uncontaminated soil, peat will result insignificantexposuretocobalt. moss, compostor manure intothesoil. In general, cobaltconcentrations in vegeta- Contaminatedsoil canalso be removed, tion rarelyexceed 1 ppm, and high cobalt orexposurecan be reduced bycoveringthe concentrationsarealmost neverfound in soil withcleansoil orsod. Soilcanalso be fruitsorseeds. Even in areas ofOntario paved overorcovered with pavingstones wherecobaltconcentrations in surfacesoil ordecking. Otherthingsyoucan do: Ministryofthe Environment . , PactSheet 1 Washyou handsandfaceand those of Sources yourchildren afterworking or playing out- ATSDR ToxFAQs- Cobalt;EnvironmentalHealth doorsand beforeeating. Center, A DivisionoftheNationalSafety 2. Cleanyour homeregularlyusinga damp Council, Washington DCCobaltChemical mopordampcloth Vacuuming and Backgrounder;ScottFlemingsnotesfromPort sweeping can increase dust levels inthe Hoperiskassessment;MurrayDixonand home. Use a phosphatecleanerat least References: once aweekespecially nearwindowsills and doors. Use rugs, curtainsand slipcov- Bowen, H.J.M., 1979. Environmental ersthatcan becleaned easily. ChemistryoftheElements. Academic Press, London. 3. Have forced airductscleaned by profes- sionalsand replacefurnacefilters often. Chaney, R.L., 1982. Fateoftoxicsubstances 4 Avoid bringingoutdoordirt inside by insludgeappliedtocropland. In/ removingoutdoorshoes. Proceedingsofan International Symposium on Land Application ofSewageSludge, 5. Brush pets often astheirfurcollectsdust Tokyo, Japan Petshould be brushed outside ifpossible 6. Keepchildren'stoysand playareasclean; Frank, R , K. Ishidaand P. Suda. 1976. discourage mouthing activitiessuch as MetalsinagriculturalsoilsofOntario. Can. J. eating dirtorsucking on dirtyobjects. Soil Sci 56:181-196 7. Beforeeating, thoroughlywash all vegeta- MOE (Ontario Ministryofthe Environment), blesthoroughlyand peel skin from root crops. 1979. Airqualitymonitoringandvegetation How can you get more samplingstudies-Cobaltarea 1976-1978. Air qualityassessment. Northeastern Region. information? Contactyourlocal office ofthe Department MOEE (Ontario Ministryofthe Environment ofPublic Health oryourmedical doctorif and Energy), 1996. Rationaleforthedevelop- youareconcernedabout being exposed to mentandapplicationofgenericsoil, ground- cobaltorhave questionsabouthealth effects. waterandsedimentcriteriaforuseatcontami- Ifyou have questionsabout possible natedsitesinOntario. PIBS 3250E01 cobaltcontamination, contactyourlocal Queen's PrinterforOntario. office ofthe Ministryofthe Environmentfor moreinformation orcall the Ministry's Public MOEE (Ontario Ministryofthe Environment Information Centreat 1-800-565-4923. and Energy), 1993. Ontariotypicalrangeof chemicalparametersinsoil, vegetation, moss bagsandsnow. PIBS 2792, Queen's Printer forOntario. Ministryofthe Environment 6Queen'sPrinterforOntario.2001 Pnntedonrecydedpaper 3793e 03/01