Evaluation of 226Ra,232Th,137Cs and 40K agaricus bisporus activity in cultivated edible mushroom formed in Tehran Province-Iran

Introduction: natural and man made radioactive sources exist in our environment they can enter into our food chains. one of these is the soil-mushroom-human chain. high level doses of natural radiation can cause hazards to humans. materials and methods: samples of agaricus bisporus cultivated edible mushroom in tehran province- iran were collected from 7 farms. specific activity of 226ra,228ra,137cs,40k and 235u of the samples were measured by two hpge detectors. results: specific activity of 226ra,228ra,137cs and 40k in the edible mushroom samples were equal to 0.06 ± 0.03 - 0.7 ± 0.2 bq kg-1 dry,1.4 ± 0.7 bq kg-1 dry,0.1 ± 0.03- 0.3 ± 0.1 bq kg-1 dry and 920 ± 400 - 1370 ± 900 bq kg-1 dry,respectively. conclusion: as the measured concentrations of the radionuclides of interest are close or lower than mda (minimum detectable activity). consumption of the mushrooms would impose no health consequences to the consumers.