Ingestion intakes of (137)Cs by the Czech population: Comparison of different approaches.

Ingestion intakes of (137)Cs of the Czech population were calculated in two different ways - either from the measured activity of (137)Cs in components of food in combination with statistical data about consumption rates or from retention of (137)Cs in the human body obtained by whole body counting or calculated from daily urinary excretion of (137)Cs. Data from the time period since 1986 to 2015 are used. The daily ingestion intake was about 25 Bq d(-1) in 1986 and is around 0.1 Bq d(-1) at present. Both approaches of ingestion intake calculation have their advantages and disadvantages. Ingestion intake calculated from (137)Cs body content was assumed to be the most accurate as it requires fewer assumptions than the calculation from food consumption. However, calculation of (137)Cs intake from food consumption is an important tool for prediction doses after the release of radionuclides into environment. The best agreement exceeding the intakes from urine measurement 5 times at maximum was achieved when intakes calculated from food also included products from the natural environment. Without this, the ingestion intake could be under-predicted seriously up to 6 times, especially in the longer time after the release of (137)Cs into environment. Ingestion intakes up to 11 Bq d(-1) in a group of people with significant consumption of game meat containing elevated activity of (137)Cs activity were included as a special case. Various groups of foodstuffs had varying effects on the total committed effective dose from (137)Cs. Dose estimates for the Czech population from (137)Cs ingestion intake achieved 80 μSv in 1986 and not more than 2 μSv currently and were similar to those incurred by the population of neighbouring countries.