Measurements of tritium radioactivity in surface water on the upper Silesia region

Tritium is produced naturally in the upper atmosphere by cosmic radiation. Oxygen atoms combine with the radioactive hydrogen atoms (tritium) to form radioactive water molecules, which reach the Earth in rain. This radioactive water seeps into groundwater, where the tritium decays with time. By measuring the concentration of radioactive tritium in a groundwater sample, geologists can approximate the age of the water and pinpoint where the water recharges (replenishes) and discharges (exits) from an aquifer. Geologists can estimate groundwater flow rate and direction, and determine whether water from a shallow aquifer has a ready pathway to a deeper aquifer or not. The possibility of measuring the level of tritium radioactivity gave a chance to use tritium as a natural tracer in the water systems. The measurements of tritium radioactivity in groundwater are becoming important. Especially nowadays when tritium levels in precipitation have returned to pre-bomb values (4-25 TU) and the technogenic emissions of tritium are becoming more significant, and may affect its natural patterns on a local or regional scale. This article presents the results obtained in 1998 by measuring tritium radioactivity in surface-water and precipitation. All analysed samples were taken during 1995-1996, from the Upper Silesia area. The obtained results confirmed, that tritium contamination has returned to the pre-bomb values.