AARHUS UNIVERSITET 9 OCTOBER 2014 NATURAL IODINE CONTENT

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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 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 Ph. D dissertation SLIDE 2

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

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

AARHUS UNIVERSITET Why Iodine? PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 5 WHO region “Europe” › 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. 5 million) of 6– 12 years old children AND 44. 2% (393. 1 millions) of the general population in WHO Europe region [3] [1] WHO, Iodine Deficiency in Europe: A continuing public health problem, M. Andersson, et al. , Editors. 2007, World Health Organization, UNICEF: France. p. 1 -86. [2] WHO, Assessment of iodine deficiency disorders and monitoring their elimination: a guide for programme managers. – 3 rd 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, 2012. 19(5): p. 382 -387.

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 6 Iodine Status of Danish Population › The last national survey on iodine status of Danish population - 1969 [2] 55 tap water samples [1] › 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 › Dan. Thyr 2 cohorts covering the main difference in levels of iodine intake in Denmark caused by different levels of iodine in groundwater [3] [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, 1999. 140(5): p. 400 -403. [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, Dan. Thyr: Status and perspectives. European Journal of Endocrinology, 2006. 155(2): p. 219 -228.

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 7 Iodine Intake Recommended daily nutrient intake (RNI) for iodine [1] 25% Age group RNI (µg/day) 0 -59 months 90 6 -12 years 120 12 -17 years 150 Adults 150 Pregnancy/lactation 250 ? ! [2] Temporal and Spatial Variation Bioavailability Goitrogens and other factors [1] WHO, Iodine Deficiency in Europe: A continuing public health problem, M. Andersson, et al. , Editors. 2007, World Health Organization, UNICEF: France. p. 1 -86. [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 2003 - 2008, 2010, DTU Fødevareinstituttet. p. 1 -200

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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 10 Iodine Cycle ~5 µg/L 50 - 60 µg/ L Total Iodine = Iodide + Iodate + Org. Iodine No data

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 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 11

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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA Paper overview (objectives) › Paper I: Iodine concentrations in Danish groundwater: historical data assessment 19332011 (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 9. OCTOBER 2014 SLIDE 13

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 Paper 1: Data & Methodology › 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) SLIDE 14

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA Paper 1: Univariate data analysis › Iodine concentrations › › <d. l. to 1220 µg/L 90% of the samples <20 µg/L 11 samples >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: 40 -80 mbt › Dominating setting at depth of extraction (some information about 70% of the samples) 9. OCTOBER 2014 SLIDE 15

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 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 PC 1 -PC 2 score plot -> high iodine is associated mainly with reduced and alkaline groundwater (Ca. HCO 3 dominated gw) 9. OCTOBER 2014 SLIDE 16

AARHUS UNIVERSITET Paper 3 PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 17 › Despite the same geology at local scale (0. 1 -0. 2 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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA Paper 4 9. OCTOBER 2014 SLIDE 18 2, 5 m depth lacustrine gyttja › GRUMO – iodine included since 2011 2, 2 -7, 1µg/L 1 -4, 2 µg/L 2, 2 -25 µg/L Glacial melt-water aquifers 2 -48 µg/L

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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 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 drinkingwater sampling campaign for assessment of dietary iodine intake and human health outcomes 9. OCTOBER 2014 SLIDE 20

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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 Paper 2: Iodine concentration & speciation › 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 m 3/year SLIDE 22

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 23 Paper 2: Governing factors › 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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 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: 212 -221

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

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

AARHUS UNIVERSITET PHD DEFENCE DENITZA D. VOUTCHKOVA 9. OCTOBER 2014 SLIDE 27 General Conclusion › Main findings › Iodine concentration › GW – from < d. l. up to 14, 5 mg/L › DW – from <d. l. up to 126 µg/L (could be even higher) › 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 › Iodine speciation › GW – mainly iodide and DOI (reduced gw) › DW – 6 different combinations › Spatial pattern › GW – both large scale trends and small (local) scale heterogeneity › DW – complex; multiple governing factors › Importance to population’s nutrition › Estimated contribution to dietary intake from 0% to >100% of RNI in different parts of the country › Jutland – the biggest variation

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