Distribution of ¹²⁹I in terrestrial surface water environments

The global distribution of the radioactive isotope iodine-129 in surface waters (lakes and rivers) is presented here and compared with the atmospheric deposition and distribution in surface marine waters. The results indicate relatively high concentrations in surface water systems in close vicinity of the anthropogenic release sources as well as in parts of Western Europe, North America and Central Asia. ¹²⁹I level is generally higher in the terrestrial surface water of the Northern hemisphere compared to the southern hemisphere. The highest values of ¹²⁹I appear around 50°N and 40°S in the northern and southern hemisphere, separately. Direct gaseous and marine atmospheric emissions are the most likely avenues for the transport of ¹²⁹I from the sources to the terrestrial surface waters. To apply iodine-129 as process tracer in terrestrial surface water environment, more data are needed on ¹²⁹I distribution patterns both locally and globally.