Naturligt forekommende stoffer i jord eller grundvand og deres sundhedseffekter 19. juni 2012 2012
Indholdsfortegnelse Side MEDICAL GEOLOGY 1 A NECESSARY TOOL IN ENVIRONMENTAL HEALTH Geolog Olle Selinus, Geological Survey of Sweden/Linneaus Univ., Kalmar LITHIUM IN DRINKING WATER AND POSSIBLE IMPLICATIONS 3 ON MENTAL HEALTH Geolog Lisbeth Flindt Jørgensen, GEUS IODINE IN GROUNDWATER IN DENMARK AND IMPLICATIONS 5 FOR HUMAN HEALTH Ph.d. Denitza Voutchkova, GEUS HELBREDSEFFEKTER AF CALCIUM OG MAGNESIUM 9 I DRIKKEVANDET Professor emeritus Erik Arvin, DTU Miljø EN REGISTERUNDERSØGELSE AF DEN DANSKE BEFOLKNING. 13 HYPPIGHEDEN AF MEDFØDTE MISDANNELSER I MANDLIGE KØNSORGANER OG FOREKOMST AF BRYST-, BLÆREHALSKIRTEL OG ÆGGESTOKKRÆFT BLANDT BEFOLKNINGEN MED ENKELT- VANDSFORSYNING Seniorrådgiver Walter Brüsch, GEUS RADON I BOLIGER 15 Ingeniør Jesper Bruun Petersen, NIRAS A/S FLUORID I DRIKKEVAND OG CARIES HOS BØRN 17 ERFARINGER MED SAMKØRING AF REGISTERDATA VEDRØRENDE MILJØ OG SUNDHED Ledende embedslæge, lektor, ph.d. Henrik Bøggild, Aalborg Universitet, Institut for Medicin og Sundhedsteknologi, Biomedicin og Sundhedsstyrelsen, Embedslægerne Nordjylland FORURENING AF GRUNDVANDET MED NATURLIG KLOROFORM 19 Seniorforsker Troels Laier, GEUS Til notater 21
MEDICAL GEOLOGY A NECESSARY TOOL IN ENVIRONMENTAL HEALTH Geolog Olle Selinus, Geological Survey of Sweden / Linneaus University, Kalmar olle.selinus@sgu.se Abstract Medical geology is dealing with the impact of the natural environment (=geology) and human and animal health. It covers a long range of issues, for example arsenic, fluoride and lithium in water, health effects of iodine and heavy metals, radon, effects of global dust storms also affecting Denmark, mass poisoning from the effects of coal in Europe, the moose disaster in Sweden etc. Many people believe that nature is clean but the lecture will show the impact of our natural environment on our health. But also demonstrate the positive effects because our food and nutrients are derived from our environment. Medical Geology has grown rapidly in 15 years. It brings together geoscientists and medical/public health researchers to address health problems caused by geological materials and processes. In January 2006 the International Medical Geology Association (IMGA) was established ( http://www.medicalgeology.org). IMGA has organised itself into chapters all over the world, one active chapter in Denmark. International conferences are arranged every second year, the most recent one in Italy 2011 with 400 participants and the next one 2013 in Washington DC. Short courses have been presented in 40 countries and have been attended by thousands of students and professionals with backgrounds in geoscience, biomedical/public health science, environmental science, geography, engineering, chemistry, etc. The lecture will bring to attention the different aspects of medical geology with several examples from Scandinavia and will also deal with how Denmark can be an important and active part in this global initiative. 1
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LITHIUM IN DRINKING WATER AND POSSIBLE IMPLICATIONS ON MENTAL HEALTH Geolog Lisbeth Flindt Jørgensen, GEUS, lfj@geus.dk Professor Lars Vedel Kessing, Psykiatrisk Center, Rigshospitalet, KU, lars.vedel.kessing@regionh.dk Abstract: Lithium is the lightest of the alkali metals and was discovered in 1817 by Johan August Arfvedson. Lithium is present, in trace amounts, in virtually all rocks from which it is mobilized by weathering processes and transported into soils, and then leached into the groundwater and/or taken up by plants entering the food chain (Schrauzer 2002). In Denmark, lithium occurs naturally in the groundwater in concentrations between 0 and 300 µg/l, see the figure below showing results from analyses in Danish groundwater wells. The concentration of lithium in groundwater and drinking water is presumed to be comparable and stable over time due to the chemical properties of lithium. Lithium was detected in human organs and fetal tissues already in the late 19th century, leading to early suggestions of possible specific functions in the organism, but medical applications of lithium preceded studies on lithium as an essential micronutrient. The first legitimate medical application of lithium was introduced in 1949 (Cade 1949) and subsequently confirmed in early systematic landmark studies by the Danish researcher Mogens Schou and colleges (Schou et al. 1954), when lithium carbonate was found to be beneficial in manicdepressive illness (bipolar disorder). 3
A number of studies indicate that treatment with lithium have some positive side effects in terms of preventing dementia (Kessing et al 2008) and other neurodegenerative illnesses (Rybakowski 2011) as well as reducing the risk of suicide (Cipriani et al 2005, Kessing et al 2005). Further, independent investigations (Kapusta et al 2011, Ohgami et al 2009, Schrauzer & Shrestha 1990) suggest that long-term intake of low concentration of lithium as those found in drinking water may reduce the risk of suicide. Based on this knowledge, a project idea has been formulated in co-operation between Rigshospitalet and GEUS to investigate whether a livelong daily intake of low concentrations of lithium from drinking water may have an effect on the development of mental diseases, and may influence the frequency of suicides. Litterature: Cade JF 1949. Lithium salts in the treatment of psychotic excitement. Med J Aust. 2: 349-352. Cipriani A, Pretty H, Hawton K, Geddes JR 2005: Lithium in the prevention of suicidal behavior and all-cause mortality in patients with mood disorders: a systematic review of randomized trials. Am J Psychiatry; 162(10):1805-1819. Kapusta ND, Mossaheb N, Etzersdorfer E, Hlavin G, Thau K, Willeit M, Praschak-Rieder N, Sonneck G, Leithner-Dziubas K 2011: Lithium in drinking water and suicide mortality. Br J Psychiatry; 198:346-350. Kessing LV, Sondergard L, Forman JL, Andersen PK 2008: Lithium treatment and risk of dementia. Arch Gen Psychiatry; 65(11):1331-1335. Kessing LV, Sondergard L, Kvist K, Andersen PK 2005: Suicide risk in patients treated with lithium. Arch Gen Psychiatry; 62(8):860-866. Ohgami H, Terao T, Shiotsuki I, Ishii N, Iwata N 2009: Lithium levels in drinking water and risk of suicide. Br J Psychiatry; 194(5):464-465. Rybakowski JK 2011: Lithium in neuropsychiatry: a 2010 update. World J Biol Psychiatry; 12(5):340-348 Schou M, Juel-Nielsen N, Stromgren E, Voldby H 1954. The treatment of manic psychoses by the administration of lithium salts. J Neurol. Neurosurg. Psychiatry 17: 250-260. Schrauzer GN. 2002. Lithium: occurrence, dietary intakes, nutritional essentiality. J Am Coll. Nutr. 21: 14-21. Schrauzer GN, Shrestha KP 1990: Lithium in drinking water and the incidences of crimes, suicides, and arrests related to drug addictions. Biol Trace Elem Res; 25 (2):105-113. 4
IODINE IN GROUNDWATER IN DENMARK AND IMPLICATIONS FOR HUMAN HEALTH Ph.d. Denitza Voutchkova 1, 2, Søren Munch Kristiansen 1, Birgitte Hansen 2, Brian Sørensen 2, Vibeke Ernstsen 2, Kim Esbensen 2 1 Aarhus University, Department of Geoscience 2 Geological Survey of Denmark and Greenland, GEUS BACKGROUND AND OBJECTIVE Increasing awareness of the importance of geological influence on the human health in Denmark as well as globally has resulted in initiation of a GEO-center project on Iodine in the hydrological cycle in Denmark: implications for human health. The project is running from 2011-2014 and comprises the iodine cycle from precipitation over soil water, groundwater and finally to tap water. Iodine is essential component of the thyroid hormones regulating the metabolic processes in cells and playing role in the early development of most organs. Low iodine intake, <150 µg/day for adults and adolescents, can result in a variety of iodine deficiency disorders, for example, mental retardation, goitre, and hypothyroidism. On the other hand, chronically high intake can also cause health problems such as iodine induced hyperthyroidism, elevated goitre, and subclinical hypothyroidism [1]. In 1998 Denmark started a voluntary fortification program of table salt aiming to increase the average iodine intake of Danish citizens by 50 µg/day. After evaluation, it has been decided that the program has failed and from 2000 a mandatory fortification (13mg/kg) of the household salt and the salt used for commercial production of bread was implemented instead [2]. Rasmussen et al. [3] calculated that 25% of the iodine intake in the average Danish diet is derived from drinking water, coffee, tea and other beverages, based on data published in 1996. However, iodine concentrations in the Danish drinking water are not measured regularly and consistently because iodine is not part of the monitoring programs of the municipal waterworks. As a consequence no historical data on a national level for the iodine content in the drinking water (tap water) exists. As part of some Danish endocrinological and dietary studies, national sampling campaigns have been executed and the results are reported in three papers [4], [3], and [5]. Additionally, the National Food Institute has published a list with iodine measurements from tap water samples taken from households at 47 locations distributed throughout Denmark [6]. Based on these data it is known that iodine concentration in the drinking water varies from 0.7 to 140 µg/l. Both the highest and the lowest measured concentrations are found in Jutland, [4], [5], [6]. However there is one order of magnitude difference between the highest values reported by [4], [5], [6] and the ones found by [3]. The objectively existing regional variation of the Iodine content in the Danish drinking water has not been studied in details from a geochemical point of view. The aim of the present project is to combine the medical and the geochemical aspect by studying the spatial and/or temporal variations in iodine bioavailability in groundwater and to evaluate the human health effects. In contrast to the drinking water data, historical iodine data mainly from groundwater 5
monitoring program (GRUMO) exists and it is available in the Danish public nationwide geological and hydrological database (Jupiter) [7]. As a first approach to study the geochemical aspects of Danish groundwater enriched in iodine, the iodine source in the sediments and the governing processes of its distribution and variations was investigated. In this study we tested two hypotheses: 1) Iodine enrichment is originating from marine deposits and infiltrating seawater nearby the present coastline, and 2) Iodine enrichment is due to desorption of iodine from old, Cretaceous marine deposits. Materials and Methods Historical groundwater data from the Jupiter data base was subjected to multivariate data analysis (Principle Component Analysis and Partial Least Squares Regression) and also illustrated by conventional traditional hydrogeochemical tools (i.e. elemental ratios). Multivariate analysis allows studying the interactions between different (more than two) elements, an aspect lacking in single-element studies. This may be important as geochemically similar elements may/will be correlated, and the study of physiology recognises that such correlated element behaviour can be synergistic or antagonistic [8]. The used Jupiter data includes information about all groundwater samples analysed for Iodine from 1933 to 2011 (2562 samples distributed in whole Denmark). Results and discussion Results of this initial study on the origin of iodine in Danish groundwater, as well some future plans, will be presented. The data structure and the correlation between Iodine and 19 other variables were examined with partial least squares regression, was revealed to be comprised by 3 clusters of samples (n=46), on the basis of which we found that Iodine and: Barium, Bicarbonate, Bromine, Sodium and partially Iron are positively correlated; Distance to coastline, distance to major faults, and ph are negatively correlated. Based on these findings, it is concluded that the important processes playing a role and explaining the variance in the water composition and the Iodine concentrations are: distance to the source, carbonate equilibrium, redox and ion exchange (Figure 1). Figure 1 Interpretation of the loading weights plot (result from the multivariate analysis) and the interpreted geochemical processes releasing iodine to Danish groundwater. 6
Conclusion and perspective With this study we demonstrate how information about the groundwater origin and the processes which are governing its composition can be gathered by using combination of multivariate data analysis and traditional hydrogeochemical tools (i.e., elemental ratios). Crucial for the outcome of the analysis and its reliability is the quality of the input data. Using historical hydrogeochemical data is tempting (it s public and easy to gather) but not always of the quality which is sufficient. Based on this study we cannot reject the two working hypotheses. Both release from old marine deposits (connate water) and sea water intrusion are governing the iodine concentration. It is possible that a third process is involved too organic matter brake down. Based on the partial least squares regression model we found also that the distance to faults has an important role in the iodine concentration. This finding remains unexplained. The historical data study gave us the first inside information on the Danish groundwater and will help for the planning of our future work. Further studies will focus on planning and execution of a sampling campaign in three areas of interest (Ishøj, Randers, Skagen). Based on a firm experimental and sampling design, will allow an improved control over the data quality and will allow us to study the sources and processes explaining iodine in the groundwater and in drinking water on a smaller regional scale. The long term goal of our project remains with a focus on geo-science health issues connected to iodine. References 1. Iodine Deficiency in Europe: A continuing public health problem, M. Andersson, et al., Editors. 2007, World Health Organization UNICEF: France. p. 1-86. 2. Laurberg, P., et al., The Danish investigation on iodine intake and thyroid disease, DanThyr: Status and perspectives. European Journal of Endocrinology, 2006. 155(2): p. 219-228. 3. Rasmussen, L.B., E.H. Larsen, and L. Ovesen, Iodine content in drinking water and other beverages in Denmark. European Journal of Clinical Nutrition, 2000. 54(1): p. 57-60. 4. Pedersen, K.M., et al., Iodine in drinking water varies by more than 100-fold in Denmark. Importance for iodine content of infant formulas. European Journal of Endocrinology, 1999. 140(5): p. 400-403. 5. Andersen, S., S.B. Petersen, and P. Laurberg, Iodine in drinking water in Denmark is bound in humic substances. European Journal of Endocrinology, 2002. 147(5): p. 663-670. 6. Saxholt, E., et al., Danish Food Composition Databank, in ed. 7.012008, Department of Nutrition, National Food Institute, Technical University of Denmark. 7. GEUS, JUPITER - Danmarks geologiske & hydrologiske database 2011. 8. Davies, B.E., et al., Medical Geology: Perspectives and Prospects, in Essentials of medical geology: impacts of the natural environment on public health O. Selinus, et al., Editors. 2005, Elsevier Academic Press: Amsterdam; Boston p. 1-14. 7
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HELBREDSEFFEKTER AF CALCIUM OG MAGNESIUM I DRIKKEVANDET Professor emeritus Erik Arvin DTU Miljø erar@env.dtu.dk Abstract: De mulige helbredseffekter af calcium og magnesium er interessante, dels fordi der er store variationer i koncentrationerne af de to stoffer i drikkevandet i Danmark, og dels fordi ny drikkevandsteknologi (omvendt osmose, ionbytning, kalkfældning, m.v.) reducerer koncentrationerne af ionerne i drikkevandet. Calcium er normalt den altdominerende cation i dansk drikkevand. Gennemsnitskoncentrationen af calcium i drikkevand i Danmark er ca. 84 mg/l (variation 31-160 mg/l). I modsætning hertil er gennemsnitskoncentrationen af magnesium kun ca. 12 mg/l (variation 3-46 mg/l). I forhold til det anbefalede daglige indtag af calcium og magnesium (800 mg Ca og 375 mg Mg) er bidraget fra drikkevand i Danmark beskedent. Hvis man forudsætter en daglig indtagelse af drikkevand på 1,5 liter/person, er tilskuddet af calcium og magnesium fra drikkevandet til dækning af det anbefalede daglige indtag kun på 16% for calcium og 5% for magnesium. Det er indtagelsen af fødevarer, der bidrager med langt det meste af mineralerne. For calcium s vedkommende er mælk og ost væsentlige kilder. Den eneste helbredseffekt af calcium og magnesium i drikkevandet, der er klart dokumenteret, er effekten af calcium i forhold til forebyggelsen af caries hos børn og unge (positiv effekt, se nedenfor). En relativ høj koncentration af magnesium i drikkevandet har i nogle studier indikeret en positiv effekt i forhold til forekomsten af hjerte-kar sygdomme. Andre studier har ikke kunnet påvise nogen effekt. Det er muligt, at hvis der er en positiv effekt, kan den hænge sammen med, at et relativt højt indhold af magnesium kan være korreleret med et relativt højt indhold af bicarbonat, der har en gavnlig effekt på kroppens syre/base balance. WHO undersøger for øjeblikket, om der er belæg for, at magnesium har en positiv effekt. Der knytter sig også stor usikkerhed til calcium s helbredseffekter, bortset fra effekten på caries. Nogle få studier har vist, at et højt calciumindhold i drikkevandet (stor hårdhed) fremmer udviklingen af børneeksem. Der er klart et behov for videre studier af denne mulige effekt, ikke mindst i Danmark, hvor hårdheden i drikkevandet mange steder er høj. Der er ikke givet nogen forklaring på den negative effekt af calcium i forhold til børneeksem i de få undersøgelser heraf. Der har ikke kunnet påvises nogen effekt af calcium (og magnesium) på knogleskørhed. Det har i mange år været kendt, at fluorid i drikkevand forebygger caries. Det er imidlertid en forholdsvis ny opdagelse, at calcium i drikkevand også bidrager til forebyggelse af caries hos børn og unge. Forekomsten af caries er bestemt af en række faktorer: socioøkonomiske, kulturelle, genetiske og kemiske faktorer. God forebyggende tandpleje fra både forældres side og skoletandpleje er helt afgørende forhold. 9
En statistisk undersøgelse af Bruvo et al. (2008) har vist, at også drikkevandets indhold af calcium og fluorid spiller en rolle. Netop fordi der er mange faktorer, der bestemmer carieshyppigheden, er der stor variation i forekomsten af caries, hvis man sammenligner personer på en bestemt lokalitet. Det er det store antal børn og unge, der har indgået i undersøgelsen af Bruvo et al. (2008), ca. 52.000, der har muliggjort, at man statistisk har kunnet konkludere at både calcium og fluorid hver har en selvstændig signifikant effekt på caries. Den statistiske undersøgelse af Bruvo et al. (2008) viste det nye, at foruden fluorid (F - ) har calcium (Ca ++ ) en væsentlig effekt, begge ioner beskytter mod caries. Resultaterne af en simpel F/Ca-model er vist i figur1, der indeholder den kvantitative sammenhæng mellem caries (DMF-S, se figurtekst) og koncentrationerne af fluorid og calcium i drikkevandet. Figuren viser variationer i cariestilfælde fra 1 til 5 DMF-S. Det fremgår af ligningen i figur 1, at gennemsnitskoncentrationerne i Danmark af fluorid og calcium er 0,33 mg F/l, henholdsvis 83,5 mg Ca/l. Dermed bliver den gennemsnitlige forekomst af caries ca. 2,9 DMF-S. Parametrene i modellen har en høj signifikans (p< 0,0001) og sammenhængen kan forklare 45% (R 2 ) af variationen i caries. Foruden fluorid og calcium havde ph, klorid, og bicarbonat en effekt på caries, men ved at tage en mere kompleks model i betragtning steg R 2 værdien kun fra 45% til 51%. Højere ph og bicarbonat reducerer caries, hvorimod højere kloridkoncentration øger caries. Man kan ud af den simple F/Ca-model udlede, at hvis man ændrer på koncentrationerne af calcium og fluorid, men samtidigt ønsker caries-neutralitet, dvs. uforandret antal cariestilfælde, så er substitutionsforholdet: C F = -0.006 C Ca. Det betyder, at hvis f.eks. calcium reduceres med 100 mg/l, så skal der tilsættes 0,6 mg/l fluorid. Substitutionsforholdet F/Ca er altså 0,6%. I figur 1 er vist den beregnede forekomst af caries i forskellige situationer. Punkt A repræsenterer f.eks. en vandforsyning på Sydsjælland med relativt høj calcium og fluorid, hvor DMF-S er 1,5. Punkt D repræsenterer en vandtype med ringe indhold af calcium og fluorid. Her er DMF-S ca. 4,5. Det kunne være en vandtype fra Vest- eller Nordjylland. Cariesforekomsten stiger altså en med faktor 3 fra Øst- til Vestdanmark. Ved brug af regnvand til vandforsyning, hvilket sker mange steder i verden, ville DMF-S stige til 5. Resultaterne af undersøgelsen har konsekvenser for vurderingen af fordele og ulemper ved blødgøring og afsaltning af vand og brug af regnvand til drikkevandsforsyning. Sidstnævnte udnyttes ikke i Danmark, men blødgøring og afsaltning er meget aktuelle teknologier. Effekten af at blødgøre vand er illustreret i figur 1 med punkt C og D. Ved at reducere calciumkoncentrationen med 80 mg/l øges cariesforekomsten med 1,1 DMF-S svarende til en øgning på 40%. Eksemplet svarer til brug af en såkaldt Pellet-reaktor, hvor fluoridkoncentrationen ikke ændres. Den positive effekt af calcium på forebyggelse af caries er resultatet af en direkte effekt på tandemaljen af calciumionerne i spyttet i mundhulen. Calcium kan imidlertid også indirekte have en positiv helbredseffekt derved, at calcium bidrager til udfældning af et beskyttende kalklag på overfladen af vandrør, såfremt vandet er overmættet mht. kalk. Det kan f.eks. hindre afgivelse af skadeligt cadmium, bly og kobber fra vandrør. Udfældning af et kalklag på rør forudsætter, at drikkevandet er overmættet mht. kalk. Herved får også drikkevandets koncentration af bicarbonat (alkalinitet) og vandets ph en betydning. 10
Reference Bruvo, M., Ekstrand, K., Arvin, E., Spliid, H., Moe, D., Kirkeby, S. og A. Bardow. (2008) Optimal drinking water composition for caries control in populations. J. Dental Res. 87 (4), 340-343. Figur 1. Forekomsten af caries som funktion af koncentrationerne af calcium og fluorid i drikkevandet. Caries er målt som DMF-S: decayed, missing and filled tooth surfaces. Koncentrationer er vist i mg/l. 11
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EN REGISTERUNDERSØGELSE AF DEN DANSKE BEFOLKNING. HYPPIGHEDEN AF MEDFØDTE MISDANNELSER I MANDLIGE KØNSORGANER OG FOREKOMST AF BRYST-, BLÆREHALSKIRTEL OG ÆGGESTOKKRÆFT BLANDT BEFOLKNINGEN MED ENKELTVANDSFORSYNING. Seniorrådgiver Walter Brüsch, GEUS wb@geus.dk Projekt udarbejdet af : Tina Kold Jensen, Helle Raun Andersen & Esben Budtz-Jørgensen, Syddansk Universitet. Halfdan Sckerl, Miljøcenter Ringkøbing. Børge Sommer, Sundhedsstyrelsen. Walter Brüsch, Frants von Platen-Hallermund, René K. Juhler, GEUS Abstract: In Denmark approximately 70.000 households are supplied with drinking water from private wells without the same high standard quality control as the households supplied from public water supplies. In 2004 a random sample of 628 private wells revealed that 2 out of 3 wells exceeded the threshold value for pesticides, nitrate or bacteria and one in three exceeded the threshold values for pesticides. Pesticides were found in more than 60% of the private wells, and often more than one pesticide or degradation products were detected. Some pesticides have in previous studies been found to have endocrine disrupting abilities and have been related to increased risk of certain cancer types and congenital malformations in the male reproductive tract. Due to the unique population registers in Denmark, it is possible to link data on water supply with cancer and malformations registers. The purpose of this register study was therefore to study the relationship between water supply and hormone related cancers and malformations in the male reproductive tract and to validate the quality of these registers. In this study data from seven population registers were used. The Danish Civil Registration System keeping a unique personal identification number (CPR number) for all citizens in Denmark and information about previous and current addresses. The Building and Housing Register (BBR) provided information about water supply for all addresses. Areal Information System (AIS) provided CPR numbers for the study population identified as all Danish people living in rural areas. The geological map from Geological Survey of Denmark and Greenland (GEUS) supplied a soil type to all addresses. The Danish Cancer Registry where information about breast cancer, ovarian cancer and prostate cancer were provided. The National Patient Registry and the Malformation Register keeping records of congenital malformations and operations for cryptorchidism and hypospadias (malformations in the male reproductive tract). In AIS the rural population in Denmark was defined and their CPR numbers recorded. These were linked to the health registers and CRP numbers of persons having one of the above defined diseases were identified in the rural population. In the Danish Civil Registration System the addresses of the rural population were identified and their water supply and soil type was recorded in respectively BBR and the geological map of GEUS. In this partially ecologically study among all Danish people living in rural areas, women who were supplied with water from small private wells more often gave birth to a boy with cryptorchidism compared to women supplied from a public wells. No increased risk for hypo- 13
spadias among sons of women with private water supply compared to public wells was found, but this is a rare malformation. Women and men who received water from private wells had no increased risk of respectively ovarian and breast cancer or prostate cancer. Women who lived in areas with clay soil more often experienced breast or ovarian cancer and gave birth to a boy with cryptorchidism compared to women living in areas with sandy soil. However, only the findings for breast cancer were statistically significant. This study indicates that the population receiving water from private wells may be exposed to pesticides and metabolites that may affect their health which is in accordance with previous studies. The exposure to pesticides though drinking water is low compared to the exposure from the diet, but the types of pesticides found in the drinking water differ from those found in the diet. In addition, many pesticides and metabolites are found in drinking water extracted from surface near groundwater reservoirs. This study is register based, and does therefore does not include individually based information about exposures and possible confounders. It is therefore not possible to draw conclusions about any causal relationship between drinking water and health. It was for example not possible to take into account differences in social class and occupation between people with private and public water supply. In addition, problems with some of the registers were discovered which is discussed in more details in the report. This study can therefore only suggest a possible relationship between drinking water supply and health which needs to be confirmed in other studies with more appropriate designs. Since no firm conclusions can be drawn from this study it may be argued that it should never have been performed. However, one of the purposes of the study was to investigate the validity of the registers and discover problems with linkage which was done. Miljøstyrelsen: Miljøprojekt Nr. 1174 2008 14
RADON I BOLIGER Ingeniør Jesper Bruun Petersen NIRAS A/S jpn@niras.dk Overalt i jorden findes uran. Tager man en håndfuld jord fra baghaven, indeholder den en lille smule af dette radioaktive stof. Det er helt naturligt. Fordi uran er radioaktivt, vil stoffet på et tidspunkt henfalde og danne andre radioaktive stoffer, efterhånden som det henfalder. Et af disse stoffer i rækken er radon. Radon er en gasart, som dannes i jorden, når metallet radium henfalder. Fordi radon er en gasart, kan den let transporteres rundt med poreluften i jordens umættede zone. Og herfra kan den trænge op i vores boliger. Fordi vi varmer boligen op, dannes et relativt undertryk i indeklimaet. Undertrykket driver poreluft fra jorden til boligen, som samtidig fører radon med sig. Radon er usynlig for det blotte øje, kan ikke lugtes eller smages, men er kræftfremkaldende. Når radon henfalder i indeklimaet, dannes polonium, som sætter sig på mikroskopiske partikler i luften, kaldet aerosoler. Disse trækkes med ned i lungerne, når vi ånder, og kan således deponeres i luftvejssystemet. Her vil henfaldsprocessen fortsætter og bestråle de omkringliggende celler. Den stråledosis, man hver dag modtager fra radon i hjemmet, er langt større end alle andre naturlige og menneskeskabte strålingskilder i dagligdagen. Når en celle bestråles, kan den tage skade. Afhængig af hvilke gener i cellens DNA, der beskadiges, kan skaden medføre mutationer, som på sigt kan danne kræft. Sundhedsstyrelsen vurderer, at radon er medvirkende årsag til ca. 9 procent af alle dødsfald af lungekræft herhjemme. Det svarer til lidt over 300 danskere hvert år. Verdenssundhedsorganisationen WHO anslår, at op til 170.000 mennesker verden over hvert år dør som følge af lungekræft induceret af radon. Derfor anbefaler myndighederne, at man måler radon i sin bolig, og gør noget ved det, hvis indholdet er højt. Oplægget den 19. juni 2012 vil primært fokusere på radons oprindelse og vej til lungerne samt sundhed og politisk bevågenhed. 15
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FLUORID I DRIKKEVAND OG CARIES HOS BØRN ERFARINGER MED SAMKØRING AF REGISTERDATA VEDRØRENDE MILJØ OG SUNDHED Ledende embedslæge, lektor, ph.d. Henrik Bøggild Aalborg Universitet, Institut for Medicin og Sundhedsteknologi, Biomedicin og Sundhedsstyrelsen, Embedslægerne Nordjylland heb@sst.dk Baggrund og formål Der blev gennemført et projekt der skulle beskrive mulighederne for samkøring af registerdata inden for området miljø og sundhed. Projektet havde to formål, dels at få erfaringer med brugen af administrative registre, dels at bruge registrene til belysning af en konkret problemstilling. Vi udvalgte den kendte sammenhæng mellem fluoridindhold i drikkevand og udviklingen af huller i tænderne hos børn, idet vi ønskede at undersøge om sammenhængen fortsat findes i dag, hvor der er bedre cariesforebyggelse. Metode, teknik Der blev foretaget samkøring af registerdata fra SCOR (Sundhedsstyrelsens Centrale Odontologiske Register med oplysninger om caries) og fluoridindhold i drikkevand fra Jupiter (Danmarks og Grønlands Geologiske Undersøgelse (GEUS)). Data blev sammenkørt via CPR-registret, der indeholder adressekoordinater og Bygnings- og Boligregistret (BBR), der indeholder oplysninger om vandforsyning. Husstandsindkomst blev tilføjet fra SKAT. Samkøring og analyse blev foretaget i et GIS (Geografiske Informations System) værktøj. Der blev fulgt kohorter af børn født i årene 1979, 1989 og 1999 med oplysninger om tandstatus ved 5 og 15 år, idet indberetning af tandstatus er obligatorisk i disse aldersgrupper. Samkøring af data begrænsede sig til adresser, der ifølge BBR-registret modtager vand fra anlæg til fælles vandforsyning. Der findes imidlertid ikke oplysninger der tilknytter et vandværk til en specifik adresse. Det endelige resultat af fluoriddata fra Jupiter var derfor et digitalt kort, der opdeler landet i små polygoner, hvortil der er knyttet attributter om fluoridindholdet i vandet fra et nærliggende vandværk. Alle adressepunkter med caries-oplysninger fik tilføjet fluoridoplysningerne fra kortet og var basis for den videre statistiske analyse. Hver kohorte blev dels analyseret for alle deltagere og dels for de der havde haft samme bopæl i hele perioden, hvorved eksponeringen blev anset for ens gennem hele perioden. Resultater Der fandtes en sammenhæng mellem højere fluoridindhold i drikkevand og en mindre risiko for at have caries i de blivende tænder for børn født i 1979 og 1989. Betydningen af fluoridindholdet i drikkevand for huller i mælketænderne var også til stede, men blev mindre indenfor en ti års periode. Der fandtes ligeledes en stærk sammenhæng mellem husstandsindkomst og tandsundhed. 17