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9. OCTOBER 2014 AARHUS UNIVERSITET NATURAL IODINE CONTENT IN DRINKING WATER (& GROUNDWATER) IN DENMARK DENITZA D. VOUTCHKOVA PhD DEFENCE AU.

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Presentation on theme: "9. OCTOBER 2014 AARHUS UNIVERSITET NATURAL IODINE CONTENT IN DRINKING WATER (& GROUNDWATER) IN DENMARK DENITZA D. VOUTCHKOVA PhD DEFENCE AU."— Presentation transcript:

1 9. OCTOBER 2014 AARHUS UNIVERSITET NATURAL IODINE CONTENT IN DRINKING WATER (& GROUNDWATER) IN DENMARK DENITZA D. VOUTCHKOVA PhD DEFENCE AU

2 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET PROJECT, FUNDING, PARTICIPANTS › Part of GEOCENTER project “Iodine in the hydrological cycle in Denmark: implications for human health” › Funded by the Geological Survey of Denmark and Greenland (GEUS) and Aarhus University (AU) › Financial support also from the International Medical Geology Association (IMGA) and the International Registry of Pathology (IRP) – Gardner Research Grant › Project participants and collaborators: Søren M. Kristiansen Birgitte Hansen, Vibeke Ernstsen, Brian L. Sørensen, Kim H. Esbensen, Chaosheng Zhang SLIDE 2 PhD dissertation

3 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET PRESENTATION OUTLINE › Background › PhD objectives › Iodine in groundwater – Paper 1, 3 & 4 › Iodine in drinking water – Paper 2 & Technical Note 1 › General conclusion SLIDE 3

4 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET BACKGROUND Part 1 SLIDE 4

5 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Why Iodine? › Iodine plays an essential role in human metabolism and the early development [1] › Iodine deficiency is the single most important preventable cause of brain damage” [2] › Insufficient iodine intake  43.9% (30.5million) of 6–12 years old children AND 44.2% (393.1 millions) of the general population in WHO Europe region [3] SLIDE 5 [1] WHO, Iodine Deficiency in Europe: A continuing public health problem, M. Andersson, et al., Editors. 2007, World Health Organization, UNICEF: France. p [2] WHO, Assessment of iodine deficiency disorders and monitoring their elimination: a guide for programme managers. – 3rd ed., 2007, World Health Organization: Switzerland p. 97. [3] Zimmermann, M.B. and Andersson, M., Update on iodine status worldwide. Current Opinion in Endocrinology, Diabetes and Obesity, (5): p WHO region “Europe”

6 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Iodine Status of Danish Population › The last national survey on iodine status of Danish population [2] › Correlation between tap water collected 1999 and the UI data from 1969 (r=0.68, p<0.01) [1] › USI programme  1996: decision, 1998: voluntary, 2000: mandatory › DanThyr  2 cohorts covering the main difference in levels of iodine intake in Denmark caused by different levels of iodine in groundwater [3] SLIDE 6 [1] 55 tap water samples [1] Pedersen, K.M., Laurberg, P., Nøhr, S., Jørgensen, A., and Andersen, S., Iodine in drinking water varies by more than 100-fold in Denmark. Importance for iodine content of infant formulas. European Journal of Endocrinology, (5): p [2] Munkner T. Urinary excretion of 127-iodine in the Danish population. Scand J Clin Lab Invest 1969;110:134. [3] Laurberg, P., Jørgensen, T., Perrild, H., Ovesen, L., Knudsen, N., Pedersen, I.B., Rasmussen, L.B., Carlé, A., and Vejbjerg, P., The Danish investigation on iodine intake and thyroid disease, DanThyr: Status and perspectives. European Journal of Endocrinology, (2): p

7 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Iodine Intake Recommended daily nutrient intake (RNI) for iodine [1] Age groupRNI (µg/day) 0-59 months years years150 Adults150 Pregnancy/lactation250 SLIDE 7 [1] WHO, Iodine Deficiency in Europe: A continuing public health problem, M. Andersson, et al., Editors. 2007, World Health Organization, UNICEF: France. p [2] Pedersen, A.N., Fagt, S., Groth, M.V., Christensen, T., Biltoft-Jensen, A., Matthiessen, J., Andersen, N.L., Kørup, K., Hartkopp, H., Ygil, K.H., Hinsch, H.J., Saxholt, E., and Trolle, E., Danskernes kostvaner , 2010, DTU Fødevareinstituttet. p % [2] ?! Temporal and Spatial Variation Bioavailability Goitrogens and other factors

8 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Drinking Water Supply in Denmark SLIDE 8 › Treated groundwater › Simple treatment mainly › Decentralised structure [1] Jupiter database, status December 2012 [1]

9 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Geology & Groundwater SLIDE 9

10 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Iodine Cycle SLIDE 10 No data Total Iodine = Iodide + Iodate + Org. Iodine µg/L ~5 µg/L

11 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET PHD OBJECTIVES › To map iodine concentration and speciation in DW and GW › To study the spatial patterns and to elucidate the governing factors › To evaluate the importance of the spatial variation of DW iodine to the population’s nutrition SLIDE 11

12 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET IODINE IN GROUNDWATER Part 3 SLIDE 12

13 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper overview (objectives) › Paper I: Iodine concentrations in Danish groundwater: historical data assessment (published in “Environmental Geochemistry and Health”) › To give overview on the existing gw iodine data with focus on: spatial variation, geological setting, depth of extraction › To identify geochemical associations between iodine and other variables in order to elucidate the governing factors for the spatial variation › Paper 3: Hydrogeochemical characterisation of Danish groundwater in relation to iodine › Paper 4: High resolution depth profiles of iodine concentrations in groundwater at fours multiscreen wells in Denmark: possibilities for future research SLIDE 13

14 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 1: Data & Methodology SLIDE 14 › Source: Jupiter database (November 2011) › Master dataset (MDS): 2562 x 28 › MDS is characterised by: › missing values › diversity in the data quality – different lab methods › Preparation and pre-treatment: › Detection limits › Excluding variables and samples › Missing values › Centred log-ratio transformation (clr) › Reduced MDS (r-MDS): 506 x 20 › Principle Component Analysis Iodine 1933 – 2011 (n=2562)

15 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 1: Univariate data analysis › Iodine concentrations › 200 µg/L › Mean: 13.83µg/L; Median: 5.4 µg/L › Spatial variation › Large scale trend-> Capital Region vs. Central Denmark (26.81 vs. 7.6 µg/L) › Small scale heterogeneity › Depth: mbt › Dominating setting at depth of extraction (some information about 70% of the samples) SLIDE 15

16 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 1: Multivariate analysis › Iodine, Li, B, Ba, Br are exhibiting similar variability, suggesting common source › Saline water influence, further studies needed in order to specify › Based on the PC1-PC2 score plot -> high iodine is associated mainly with reduced and alkaline groundwater (Ca- HCO3 dominated gw) SLIDE 16

17 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 3 SLIDE 17 › Despite the same geology at local scale ( km and 5-10 km) TI varied › Speciation -> reflects the prevailing reduced conditions › The processes governing iodine concentration are site and depth specific › TI at different concentration levels governed by different processes

18 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 4 SLIDE 18 › GRUMO – iodine included since ,5m depth lacustrine gyttja 2,2-7,1µg/L1-4,2 µg/L 2,2-25 µg/L 2-48 µg/L Glacial melt-water aquifers

19 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET IODINE IN DRINKING WATER Part 2 SLIDE 19

20 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper overview (objectives) › Paper 2: Assessment of spatial variation in drinking water iodine and its implications for dietary intake: A new conceptual model (published in “Science of the Total Environment”) › To identify spatial trends, clusters and/or outliers for iodine concentration and speciation and factors governing it; › To propose a new conceptual model, while illustrating the importance of the chosen generalisation for future studies › To estimate the contribution of drinking water to the dietary iodine intake › Technical Note 1: Design of a nationwide drinking- water sampling campaign for assessment of dietary iodine intake and human health outcomes SLIDE 20

21 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 2: Study design SLIDE 21 › Criteria for choosing around 180 sampling locations › Jupiter data on gw abstraction & location › Largest in each municipality › Largest in each grid cell

22 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 2: Iodine concentration & speciation SLIDE 22 › The waterworks were involved in the sampling › From the updated list (n=189) › Positive 80% (n=152) › Negative 2% (n=4) › No answer n=33 › Samples received at the lab (n=144) › 175 mio m3/year

23 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 2: Governing factors SLIDE 23 › Limitations › Mixing of different water types › Pumping strategies › Groundwater treatment › Treatment › Advanced treatment n=14 › Only aeration n=2 › Aeration + sand filter(s) – the rest › Possible effects from the treatment › Organic ↔ inorganic iodine › Iodine lost to the atmosphere (I 2 ) › Iodine removal in the treatment against ferrous iron

24 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET SLIDE 24 Paper 2: Spatial autocorrelation analysis Local Moran’s I Threshold distance d ij [a] Zhang C, Luo L, Xu W, Ledwith V. Use of local Moran's I and GIS to identify pollution hotspots of Pb in urban soils of Galway, Ireland. Science of the Total Environment 2008; 398: [a]

25 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 2: Method of generalisation SLIDE 25

26 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Paper 2: Contribution to dietary intake SLIDE 26

27 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET General Conclusion › Main findings › Iodine concentration › GW – from < d.l. up to 14,5 mg/L › DW – from 100% of RNI in different parts of the country › Jutland – the biggest variation SLIDE 27 › Project Goals › To map iodine concentration and speciation in DW and GW › To study the spatial patterns and to elucidate the governing factors › To evaluate the importance of the spatial variation of DW iodine to the population’s nutrition

28 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET SLIDE 28 Thank you for listening! Questions? Denitza Voutchkova

29 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET › Iodine intake from drinking water › Groundwater vs. surface water vs. bottled water › Registers SLIDE 29 How special is Denmark? [1] Map created by P.Engstrom &K.Brauman. Data: BGR & UNESCO (2008): Groundwater Resources of the World 1 : Hannover, Paris. Via [2] WHO 2006 Protecting Groundwater for Health; Managing the Quality of Drinking-water sources. [2] [1]

30 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 AARHUS UNIVERSITET AARHUS UNIVERSITET Is there really a connection between drinking water iodine and the iodine status of the population? › China, Denmark › Bioavailability? › How to do it › Supply area map  › Drinking water data › Exposure from drinking water › Correlation between IDD distribution and exposure SLIDE 30


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