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

Ingestion intakes of ¹³⁷Cs of the Czech population were calculated in two different ways - either from the measured activity of ¹³⁷Cs in components of food in combination with statistical data about consumption rates or from retention of ¹³⁷Cs in the human body obtained by whole body counting or calculated from daily urinary excretion of ¹³⁷Cs. 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 ¹³⁷Cs body content was assumed to be the most accurate as it requires fewer assumptions than the calculation from food consumption. However, calculation of ¹³⁷Cs 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 ¹³⁷Cs 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 ¹³⁷Cs activity were included as a special case. Various groups of foodstuffs had varying effects on the total committed effective dose from ¹³⁷Cs. Dose estimates for the Czech population from ¹³⁷Cs 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.