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Qualifying Exam. Midterm evaluation (Part A), Department of Geoscience. Denitza Voutchkova. PhD fellow. AARHUS. UNIVERSITET. 28, January 2013. TITEL P PR SENTATION – PowerPoint PPT presentation

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Title: Qualifying%20Exam

Qualifying Exam
Midterm evaluation (Part A), Department of
  • Geocenter project, financed by GEUS and AU (2011-
  • Project title Iodine in the hydrological cycle
    in Denmark implications for human health
  • Objective to combine both the medical and the
    geochemical aspect by studying the variations in
    iodine bioavailability in groundwater and to
    evaluate the human health effects.
  • Søren Munch Kristiansen
  • Birgitte Hansen
  • Kim Esbensen
  • Vibeke Ernstsen
  • Brian Sørensen

Presentation outline
  • PhD objective and structure
  • Background information
  • Summary of potential research topics
  • 1st part of the PhD Multivariate analysis of
    historical groundwater data
  • 2nd part Four case studies
  • 3rd part National study
  • Future plans

PhD objective and structure
  • To investigate the spatial variation of iodine
    concentrations and speciation in the Danish
    ground- and drinking water.
  • To elucidate the sources and processes
    influencing this variability by focusing on the
    geological and geochemical causes
  • Geoavailability, bioaccessibility and
    bioavailability of I and the human health effects.

groundwater formation and Danish geology
sources Viden om grundvand and Den Store Danske
open encyclopedia
From groundwater to Tap water
Type of organisation ww with reported abstractions ww with reported abstractions Reported abstraction volumes mio m3 / year Reported abstraction volumes mio m3 / year
Type of organisation 2010 2011 for 2010 for 2011
Small (3-9 households) 249 271 0.842 0.954
Public 337 326 216.707 208.125
Private 2246 2120 179.464 170.616
Water supply 2 1 0.875 0.852
Sum 2834 2718 397.888 380.547
Iodine cycle
No data
Iodine essential trace element
regulates the metabolic processes in cells plays
role in the early development of most organs
group RNI ug/day (WHO) UL ug/day (European commision) UL ug/day (IOM, US)
0-5yeras 90 200-250 200-300
6-12years 120 250-450 300
12-17 years 150 450-500 300-900
adults 150 600 (500) 1100
pregnant 200 600 1100
Expert committee on Human Nutrition, France
Iodine Deficiency
Median UI ug/l associated risk
Severe ID lt20 cretinism, goitre, hypothyroidism, etc.
Moderate ID 20 - 49 low IQ, goitre, hypothyroidism, hyperthyroidism
Mild ID 50 - 99 goitre, hyperthyroidism
Optimal ID 100 - 199 -
More than Adequate (Excessive) 200 299 (gt300) hypothyroidism, early Graves disease (?), (goitre)
source Laurberg at al. 2010
Source WHO 2007
  • mild ID Denmark (10 other European countries)
  • subnational surveys Denmark ( 13 other
    European countries)

Short historical overview
Denmark must be regarded as area with marginal
iodine deficiency, and in the elderly population,
especially among women, goitre is present with
high frequency (Rasmussen et al. 1996)
voluntary fortification
  • cohort studies
  • register of new cases of hyper- and
  • national register for surgical, medical, and
    radioiodine treatment

Pedersen et al. 1997
cover the main difference in levels of iodine
intake in Denmark caused by different levels of
iodine in groundwater...
(Laurberg et al. 2006)
Dietary iodine
geographical temporal (?) variation
data A.N. Pedersen at al. 2010 -gt dietary habits
in Denmark (n4431)
Urinary Iodine excretion studies, Denmark
Samples 24-hour or spot units!
  • One national study Munkner 1969
  • 17-20 years old male gymnasium students,
  • mediane 64 ug/24-hours
  • Recent studies are evaluating the effect of the
    fortification program (DanThyr)

Iodine Bioavailability
Bioavailable iodine is that which is absorbed
from the food and utilized to produce thyroid
hormones. Hurrell, 1997
  • Controlling factors
  • Iodine intake
  • Nutrient interactions
  • Goitrogens

dietary intake inorganic org. iodine
synthesis of thyroid hormones
transport of iodide, bound to plasma proteins
conversion to iodide
The ideal method to measure iodine
bioavailability in man would be to use
radioiodine and to quantify urinary and faecal
excretion as well as thyroid uptake. Hurrell
urinary iodide excretion
faecal excretion endogenous org. iodine
Goitrogens and other factors
Goitre endemias from naturally occurring
goitrogens in food
smoking malnutrition other deficiencies
Humic substances
data Gaitan, 1990
Summary of potential research topics
  • Spatial variability of I concentration and
    speciation from drinking water and groundwater
  • Temporal variation of I concentration and
    speciation from drinking water combined with the
    variation in milk
  • Bioavailability of I and I species
  • Combined effect of I and other chemical elements
    from the drinking water on the human health (e.g.
    water hardness, Li, Fe, Se, etc.)
  • Recognising population groups with potential
    insufficient intake based on the variability of I
    concentration and speciation in water
  • Correlation between I intake from water and
    registered cases of IDD on municipality scale for
    whole Denmark

1st part Multivariate analysis of historical
groundwater data
  • Objectives
  • To identify the factors (both I sources and key
    processes) governing I content in Danish
  • To find out in what way the I content is
    influenced by these factors
  • Methods and materials
  • Data from Jupiter The Danish public nationwide
    geological and hydrological database
  • Multivariate data analysis PCA PLS-R
  • Traditional geochemical tools redox type
    saturation indexes Na/Cl ratio and Cl/Br ratio

1st part
(No Transcript)
1st part Outcome
  • Data quality !
  • Interpreting the positive correlation of
  • I to Ba, HCO3-, Br, Na and partially Fe, and the
    negative correlation of I to distance to the
    coast line, major faults, and pH
  • Specifying one dominating source of I is not
    consistent with the general complexity revealed
    by the MVDA
  • Studying the I variation on a smaller scale would
    most probably give better results

2nd part 4 Case studies, Sampling sites
  • Skagen 4 wells
  • Oust Mølle 4 wells
  • Bunkedal 3 wells
  • Østrup Skov 3 wells
  • Vilstrup 4 wells
  • Ishøj 4 wells two depths at 1 well
  • Stevns 1well (3 depths)
  • Lab measurements I, IO3, TI, DOC, TIC, TN,
    NO3, NH4, Alkalinity, Cl, PO4, SO4, Br, F, Ca,
    Mg, K, Na, Fe, Mn
  • Field measurements pH, O2, t, conductivity,

2nd part Objective
  • To compare and explain the I concentration and
    speciation in the groundwater and its spatial
    variation on different scales, between the wells
  • at one waterwork
  • from different waterworks in one area (Randers)
  • from different areas (Skagen vs. Randers).
  • To compare and explain the differences/similaritie
    s between I concentration and speciation in raw
    groundwater and drinking water (for both Skagen
    and Randers)
  • To elucidate the I sources and the governing
    processes by using hydrogeochemical tools (and
  • Two hypotheses about the I origin are going to be
  • seawater intrusion at the aquifer (Ishøj)
  • upward transport (advection) of old saline water

2nd part Sampling
type of well
2nd part
Pure drinking water sampling
3rd part National Sampling Campaign Objective
  • overview on I speciation in Danish drinking water
    for first time
  • concluding on the spatial variation of I and
    confirm/oppose previous findings, questioned
    because of the sampling campaigns design
  • optimizing the estimation of the dietary I intake
    from water (higher resolution)
  • evaluate the correlation with other chemical
  • distinguishing between types of water or regions
    where it is present and to assess the relevance
    for I deficiency
  • correlation with epidemiological data for chosen
    I related diseases on a municipality level

3rd part
  • Selection criteria
  • The largest waterwork in each municipality
  • The largest waterwork for each cell
  • Checking and substituting of some of the chosen
    waterworks for bigger ones

Plans for the future
  • PHD thesis consisting of at least 3 publications
  • High-Iodine Danish Groundwaters a Multivariate
    Data Analytical Survey
  • Sources and Speciation of Iodine Four Danish
    Case Studies
  • Speciation of Iodine in Danish Drinking Water
    a Nation-wide Assessment
  • Estimation of Dietary I Intake from Water and
    Assessment of the ID Risk on Municipality Level
  • Other ?
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