Electronic Supplementary Materials (ESM)

Electronic supplementary materials (ESM)

Iodine in major Danish aquifers

Submitted to Environmental Earth Sciences

Denitza Dimitrova Voutchkova1,2,4, Vibeke Ernstsen3, Søren Munch Kristiansen4, Birgitte Hansen*2

[1] Department of Geography, National University of Singapore, AS2, #03-01, 1 Arts Link, Kent Ridge, Singapore 117570 (current affiliation)

[2] Geological Survey of Denmark and Greenland (GEUS), Lyseng Allé 1, DK-8270 Højbjerg, Denmark

[3] Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, DK-1350 Copenhagen K, Denmark

[4] Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, DK-8000 Aarhus C, Denmark

e-mail (DDV):

Contents

1 ESM Figures 2

2 ESM Tables 5

3 References 7

1 ESM Figures

ß ESM Figure 1 Flow-through cell with pH, conductivity, dissolved O2, redox status, and temperature sensors used for establishing “stable” conditions during pre-pumping of the wells and for following in situ measurements.

ESM Figure 2 Map of Denmark showing the geographical distribution of recent marine sediments (parent material at 1m depth) and the extend of the pre-Quaternary chalk/limestone deposits; the drinking water iodine data is from Voutchkova et al. (2014a)

ESM Figure 3 Total iodine vs. depth (a), pH (b), and conductivity (c)

ESM Figure 4 Total iodine vs. Cl⁻ (a), Br⁻ (b), F⁻ (c), Na⁺ (d), K⁺ (e), SO4⁻ (f), Ca²⁺ (g), Mg²⁺ (h), HCO3⁻ (i)

ESM Figure 5 Depth profiles of total nitrogen, NO3⁻-N, NH4⁺-N, total iodine (TI), IO3-I, iodide (I⁻), and dissolved organic carbon (DOC) in groundwater at Stevns-2

ESM Figure 6 Relation between deuterium excess and total iodine (TI)

2 ESM Tables

ESM Table 1 Iodine concentration and speciation in the hydrosphere (based on literature sources)

Type of water / TI range, µg/L / Species / Characteristics / Source
Sea water / 50 - 60 / IO3⁻, I⁻, DOI, CH3I and other forms, I2, particulate I / Review paper / Ito and Hirokawa (2009)
32-89* / IO3⁻, I⁻, TI / Skagerrak (Denmark), Seasonal variation / Truesdale et al. (2003)
Precipitation / 0.5 - 20 / - / Rain and snow (review paper) / Fuge and Johnson (1986)
2 - 5 / I⁻, IO3⁻ / Rain; UK: lower concentrations from the interior, higher from the coastal areas; / Fuge (2005)
2.2 ± 0.8 / - / Rain; Germany / Gilfedder et al. (2009)
0.78 - 2.7 / dominating IO3⁻ / Rain; Roskilde (Denmark) / Hou et al. (2009)
0.48 - 0.68* / dominating I⁻ / Chile / Biester et al. (2006)
Surface water / 0.01 - 73 / - / Non-marine surface waters; mean for river water 5 µg/L (review paper) / Fuge and Johnson (1986)
1.9 ± 0.3 / DOI, IO3⁻, I⁻, / Humic rich headwater lake (Mummelsee, Germany); uniform throughout the year / Gilfedder et al. (2009)
10 - 20* / dominating DOI / pore-water from 3 peat bogs (Chile) / Biester et al. (2006)
Groundwater / <0.4 - 1220
Mean: 13.83
Median: 5.4 / - / Denmark, Jupiter dataset 1933-2011 (n=2562) / Voutchkova et al. (2014b)
0.02 – 4117 / dominating I⁻, org.I, IO3⁻ / Central Shanxi province, China; >70% of the samples are with TI >150 µg/L; n=950 / Tang et al. (2013)
3.31 – 1890
Mean 209 / dominating I⁻ / Datong Basin, Northern China; 2009-2010 n=76 / Li et al. (2013b)
6.23 – 1380
Median 116 / dominating IO3⁻, I⁻, DOI / Datong Basin, Northern China; / Li et al. (2013a)
Spring and mineral water / <0.2 - 4030
Median 4.78 / - / bottled mineral water (Europe); many of the elevated TI – from formation waters or recent marine sediments / Reimann and Birke (2010)
1.6 - 1270* / - / thermal and non-thermal springs (review paper) / Fuge and Johnson (1986)
Brines and formation waters / 4 - 380* / - / Brines (review paper) / Fuge and Johnson (1986)
129 ± 3 x103
71 ± 6 x103
10 ± 3 x103 / - / Brines (Mobara, Narita, Tokyo); mobilization from subducting marine sediments / Muramatsu et al. (2001)
Drinking water / <0.2 - 126 / I⁻, IO3⁻, DOI / Treated drinking water (n=144); groundwater origin (Denmark) / Voutchkova et al. (2014a)
2.5 – 432.3** / - / drinking water (mixed drinking water sampling – wells or pipelines of supply system if exists) China (n=1097) / Li et al. (2012)

*range of the means

**range of median

Table 2 Literature data on the range and linear correlation between δ18O and δD for Danish precipitation, groundwater and sea water

fitted lines / R2 / δ18O range
‰ / δD range
‰ / Characteristics / reference
δD = 7.4 δ18O – 1.7 / 0.96 / -9 to -5 / -70 to -40 / Pore- water from boreholes Stevns-1 (only for Cl > 250ppm) / (Bonnesen et al., 2009)
- / - / -8.24 to -6.92 / -53.6 to -44.5 / “Brown water” from various aquifers of Quaternary and Miocene sandy deposits; Southwest Jutland / (Jørgensen et al., 1999)
δD = 6.8 δ18O – 2.2 / 0.99 / - / - / 76 samples from piezometer wells along a transect normal to the coastline (1 to 9 m depth); groundwater-seawater mixing line; slope 6.8 reflects mixing of seawater and freshwater in the shallow aquifer, Isefjord / (Jørgensen et al., 2008)
- / - / -8.9 to -8.5 / -62 to -58 / Unmodified deep groundwater from 2 wells (185.56 and 185.21C) from limestone aquifer, and 4 observational boreholes in marine/aeolian sandy aquifer;
- / - / -4.8 to -3.5 / -35 to -22 / Brackish seawater from Isefjord 15-24 ‰ salinity; In accordance with shallow waters in the central part of the Baltic Sea (?)
- / - / -10.7 to -5.6 / -84 to 34 / Rainwater July-September 1999 Læsø; Close to GMWL / (Jørgensen, 2002)
- / - / -9.6 to -7.5 / -66 to -54 / Groundwater from water wells and dug wells Læsø; Close to GMWL
- / - / -1.5 / -20 / Sea water Kattegat (Læsø); in agreement with Baltic sea studies on deuterium and salinity
δD =3 δ18O – 55 / 0.82 / -4.3 to -1.2 / -34 to -16 / Local groundwater-seawater mixing line; saline groundwater samples
δD =3.2 δ18O – 33 / 0.99 / -1.5 to +17.53 / -19.9 to +37.3 / Pan experiment (to study the effect of evaporation on seawater) natural local sea water salinity 2.1% (July –August 1999) samples collected at salinities 2.7, 7.6, 10.5, 14.7
- / - / -8.65 to -7.95 / -58.2 to -54.0 / Groundwater from 2 wells, multilevel sampling, different Cl content ranging from 25 to 990 mg/l; Aarhus, Stautrup; / (Jørgensen and Holm, 1995)
- / - / -1.68 / -1.71 / -4.9 / -5.2 / Sea water, Aarhus bay, Cl=10500 mg/l
- / - / -7.99 to -3.27
(av: -5.65) / -65 to -20.7
(av: -40.87) / Precipitation Odense station (1984, ‘72, ‘71, ‘70, ‘63, ‘64). (n=6) / GNIP database (IAEA, Water Resources Program)
- / - / -14.02 to -5.62
(overall av: -9.68) / -105.2 to -36.6
(overall av: -68.16) / Precipitation Taastrup station (1965-71). (n=52)
δD =7.42δ18O +2.65 / 0.97 / -12.31 to -3.27 / -92.54 to -20.7 / Precipitation based on weighted annual means for Taastrp and Odense

3 ESM References

Biester H, Selimović D, Hemmerich S, Petri M. Halogens in pore water of peat bogs - The role of peat decomposition and dissolved organic matter. Biogeosciences 2006; 3: 53-64.

Bonnesen EP, Larsen F, Sonnenborg TO, Klitten K, Stemmerik L. Deep saltwater in Chalk of North-West Europe: Origin, interface characteristics and development over geological time. Hydrogeology Journal 2009; 17: 1643-1663.

Fuge R. Soils and Iodine Deficiency. In: Selinus O, Alloway BJ, Centeno JA, Finkelman RB, Fuge R, Lindh U, et al., editors. Essentials of medical geology: impacts of the natural environment on public health Elsevier Academic Press, Amsterdam; Boston 2005, pp. 417-433.

Fuge R, Johnson CC. The geochemistry of iodine - a review. Environmental Geochemistry and Health 1986; 8: 31-54.

Gilfedder BS, Petri M, Biester H. Iodine speciation and cycling in fresh waters: A case study from a humic rich headwater lake (Mummelsee). Journal of Limnology 2009; 68: 396-408.

Hou X, Aldahan A, Nielsen SP, Possnert G. Time series of 129I and 127I speciation in precipitation from Denmark. Environmental Science and Technology 2009; 43: 6522-6528.

Ito K, Hirokawa T. Iodine and Iodine species in Seawater: Speciation, Distribution, and Dynamics. In: Preedy VR, Burrow GN, Watson R, editors. Comprehensive Handbook of Iodine Nutritional, Biochemical, Pathological and Therapeutic Aspects. Academic Press, London, 2009, pp. 83-91.

Jørgensen NO. Origin of shallow saline groundwater on the Island of Læsø, Denmark. Chemical Geology 2002; 184: 359-370.

Jørgensen NO, Andersen MS, Engesgaard P. Investigation of a dynamic seawater intrusion event using strontium isotopes (87Sr/86Sr). Journal of Hydrology 2008; 348: 257-269.

Jørgensen NO, Holm PM. Strontium-Isotope Studies Of Chloride-Contaminated Groundwater, Denmark. Hydrogeology Journal 1995; 3: 52-57.

Jørgensen NO, Morthorst J, Holm PM. Strontium-isotope studies of "brown water" (organic-rich groundwater) from Denmark. Hydrogeology Journal 1999; 7: 533-539.

Li J, Wang Y, Guo W, Xie X, Zhang L, Liu Y, et al. Iodine mobilization in groundwater system at Datong basin, China: Evidence from hydrochemistry and fluorescence characteristics. Science of the Total Environment 2013a; 468-469: 738-745.

Li JX, Wang YX, Xie XJ, Zhang LP, Guo W. Hydrogeochemistry of high iodine groundwater: a case study at the Datong Basin, northern China. Environmental Science-Processes & Impacts 2013b; 15: 848-859.

Li WH, Dong BS, Li P, Li YF. Benefits and risks from the national strategy for improvement of iodine nutrition: A community-based epidemiologic survey in Chinese schoolchildren. Nutrition 2012; 28: 1142-1145.

Muramatsu Y, Fehn U, Yoshida S. Recycling of iodine in fore-arc areas: Evidence from the iodine brines in Chiba, Japan. Earth and Planetary Science Letters 2001; 192: 583-593.

Pratt A. Typediagrammet til klassificering af vandtyper - en opdatering. DanskVand 2003: 206-208.

Reimann C, Birke M. Geochemistry of European Bottled Water. Stuttgart, Germany: Borntraeger Science Publishers, 2010.

Tang Q, Xu Q, Zhang F, Huang Y, Liu J, Wang X, et al. Geochemistry of iodine-rich groundwater in the Taiyuan Basin of central Shanxi Province, North China. Journal of Geochemical Exploration 2013; 135: 117-123.

Truesdale VW, Danielssen DS, Waite TJ. Summer and winter distributions of dissolved iodine in the Skagerrak. Estuarine, Coastal and Shelf Science 2003; 57: 701-713.

Voutchkova DD, Ernstsen V, Hansen B, Sørensen BL, Zhang C, Kristiansen SM. Assessment of spatial variation in drinking water iodine and its implications for dietary intake: A new conceptual model for Denmark. Science of the Total Environment 2014a; 493: 432-444.

Voutchkova DD, Kristiansen SM, Hansen B, Ernstsen V, Sørensen BL, Esbensen KH. Iodine concentrations in Danish groundwater: historical data assessment 1933–2011. Environmental Geochemistry and Health 2014b: 1-14.