1. DENITZA VOUTCHKOVA PHD FELLOW AARHUS UNIVERSITET 27. AUGUST 2013 DIETARY IODINE INTAKE FROM DRINKING WATER IN DENMARK AU Background information and methodological discussion Medgeo2013 5 th International Conference on Medical Geology (MedGeo 2013) Arlington, Virginia (USA), August 25 - 29, 2013 contributors: Ernstsen, V.; Esbensen. K.; Hansen, B.; Kristiansen, S.; Sigsgaard, T; Sørensen, B.;

2. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 WHO ARE WE? Iodine in the hydrological cycle in Denmark: implications for human health 2 Europe Denmark GEUS AU Vibeke Ernstsen Søren M. Kristiansen Birgitte Hansen Kim Esbensen Brian Sørensen

3. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 PRESENTATION OUTLINE Iodine and human health: deficiency, dietary intake, bioavailability, etc. National study objectives Specifics of the drinking water supply in Denmark Sampling design and implementation Analytical program and iodine speciation Overview on the medical geology study concept Summary 3

4. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 IODINE – ESSENTIAL TRACE ELEMENT 4 regulates the metabolic processes in cells plays role in the early development of most organs toxicity deficiency intake function Safe and adequate intake RNI UL groupRNI ug/day (WHO) UL ug/day (European commision) UL ug/day (IOM, US) 0-5yeras90200-250200-300 6-12years120250-450300 12-17 years150450-500300-900 adults150600 (500)*1100 pregnant2006001100 * Expert committee on Human Nutrition, France

5. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 IODINE DEFICIENCY 5 Median UI ug/lassociated risk * Severe ID <20 cretinism, goitre, hypothyroidism, etc. Moderate ID 20 - 49 low IQ, goitre, hypothyroidism, hyperthyroidism Mild ID 50 - 99goitre, hyperthyroidism Optimal ID 100 - 199- More than Adequate (Excessive) 200 – 299 (>300) hypothyroidism, early Graves’ disease (?), (goitre) Source: WHO 2007 * source: Laurberg at al. 2010

6. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 SHORT HISTORICAL OVERVIEW 6 1996 1998 2000 DanThyr mandatory decision Pedersen et al. 1999 voluntary fortification

7. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 DIETARY IODINE 7 mi9.com 18% Kirsten Hjørne 6% Fotolia, Valentyn Volkov 32% 2% Belgravia imports 19% Iodine colourbox.dk news.priyo.com Crate&Barrel 14% after geographical temporal (?) variation data: A.N. Pedersen at al. 2010 -> dietary habits in Denmark (n=4431) ~25% before Rasmussen et al. 2000

8. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 IODINE BIOAVAILABILITY 8 “ Bioavailable iodine is that which is absorbed from the food and utilized to produce thyroid hormones.” Hurrell, 1997 © Smithsonian Institution urinary iodide excretion conversion to iodide faecal excretion: endogenous org. iodine dietary intake: inorganic + org. iodine transport of iodide, bound to plasma proteins ~100% 85÷90% inorganic I absorbed 10÷15% urinary excretedbioavailable ? % organic I Bioavailability controlling factors: Iodine intake Nutrient interactions Goitrogens synthesis of thyroid hormones

9. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 NATIONAL STUDY OBJECTIVE(S) 9 iodine speciation Mapping iodine speciation in drinking water; Hydrogeochemical associations with other elements & parameters dietary iodine Estimating the dietary iodine intake from water Areas with low/high intake; IDD risk assessment incidence rates Calculating incidence rates for chosen IDD Is there a correlation with iodine in drinking water?

10. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 DRINKING WATER SUPPLY IN DENMARK 10 groundwater aeration tank sand filter drinking water storage tank www.aarhusvand.dk

11. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 11 SAMPLING DESIGN AND IMPLEMENTATION Initial selection Updated selection and execution 186  189  152  142

12. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 12 IODINE SPECIATION TI (ICP-MS) Example from one site (another study) groundwater IO 3 ¯ (IC) I¯ (IC) drinking water 12 Organic bound iodine Organic bound iodine Inorganic iodine Total iodine Other iodine complexes ? Other iodine complexes ?

13. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 13 IODINE AND OTHER ELEMENTS groundwater PCA on clr transformed groundwater data (n=506) Example (another study) Drinking water & Health Iodine species FeLiSe Ca & Mg

14. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 COMBINING HEALTH AND WATER QUALITY DATA Concentrations of Iodide, Iodate, and Total Iodine 142 locationsSupplied areasExposure areas Incidence rates for chosen iodine related diseases Drinking water sampling campaign 2013 The Danish Civil Registration System + Different Health registers GIS … to be continued Collaboration with: Department of Public Health (AU) Centre for Integrated Register-based Research (CIRRAU)

15. AARHUS UNIVERSITET MEDGEO2013 DENITZA VOUTCHKOVA 27. AUGUST 2013 major contributor Drinking water (groundwater origin) is major contributor to the dietary iodine intake in Denmark New nationwide study New nationwide study on iodine speciation and variability in Danish drinking water has been designed and implemented in 2013 voluntarily Success in involving the private and public water companies to participate voluntarily in our investigation On going On going laboratory analysis and application for obtaining data from the civil registration system and the health registers 15 SUMMARY