Environmental issues relating to iodine deficiency


UK Iodine Group members, particularly Dr Alex Stewart, are actively involved in reviewing the environmental determinants of iodine deficiency.


Summary of main points:

  • It is considered that community or personal iodine deficiency = low dietary intake, and that low dietary iodine = low environmental iodine. However, is this true?
  • Not all studies have confirmed reports that there is an inverse relationship between soil or water iodine and goitre or iodine deficiency. i.e. that low iodine in the soil or water causes goitre. 
  • Many recent health-based sources, journal articles and websites on iodine have inaccurate statements on environmental iodine, based on outdated beliefs around iodine transformations and movements in the environment.
  • The release of iodine from seawater to air is more complex than volatilisation of iodide.
  • Rain adds iodine to soil, rather than removes it.
  • Atmospheric iodine is very reactive and is involved in ozone, sulphur and organic chemistry.
  • The movement of iodine from air to plant and soil and then into the diet is poorly understood.
  • Glaciation, leaching, flooding and erosion do not necessarily lead to environmental iodine deficiency.
  • Other factors (such as Brassica vegetables, some minerals, poverty and social situations) may affect the production of iodine deficiency disorders in unknown ways.


Text written by Dr Alex Stewart (December 2015)

There is a more detailed review of the relationship between the environment and iodine deficiency here.