Medgeo2013

1
contributors Ernstsen, V. Esbensen. K. Hansen,
B. Kristiansen, S. Sigsgaard , T Sørensen, B.

Medgeo2013
5th International Conference on Medical Geology
(MedGeo 2013) Arlington, Virginia (USA), August
25 - 29, 2013
2
Who are we?

• Iodine in the hydrological cycle in Denmark
  implications for human health

GEUS AU
Birgitte Hansen
Vibeke Ernstsen
Søren M. Kristiansen
Kim Esbensen
Brian Sørensen
3
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

4
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
5
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
6
Short historical overview
decision
DanThyr
voluntary fortification
mandatory
7
Dietary iodine
geographical temporal (?) variation
data A.N. Pedersen at al. 2010 -gt dietary habits
in Denmark (n4431)
8
Iodine Bioavailability
Bioavailable iodine is that which is absorbed
from the food and utilized to produce thyroid
hormones. Hurrell, 1997
dietary intake inorganic org. iodine
synthesis of thyroid hormones
transport of iodide, bound to plasma proteins
conversion to iodide
urinary iodide excretion

• Bioavailability controlling factors
• Iodine intake
• Nutrient interactions
• Goitrogens

faecal excretion endogenous org. iodine
9
National study Objective(s)

• Mapping iodine speciation in drinking water
• Hydrogeochemical associations with other elements
  parameters

• Estimating the dietary iodine intake from water
• Areas with low/high intake IDD risk assessment

• Calculating incidence rates for chosen IDD
• Is there a correlation with iodine in drinking
  water?

10
Drinking water supply in Denmark
www.aarhusvand.dk
11
Sampling Design and Implementation
186 ? 189 ? 152 ? 142
12
Iodine speciation
12
13
Iodine and other elements
Example (another study)
PCA on clr transformed groundwater data (n506)
14
Combining Health and Water quality Data

• Collaboration with
• Department of Public Health (AU)
• Centre for Integrated Register-based Research
  (CIRRAU)

Incidence rates for chosen iodine related diseases
The Danish Civil Registration System Different
Health registers
GIS
Concentrations of Iodide, Iodate, and Total Iodine
Drinking water sampling campaign 2013
to be continued
15
Summary

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