Radiotoxic 210Po and 210Pb in uncooked and cooked Boletaceae mushrooms from Yunnan (China) including intake rates and effective exposure doses

The article presents results of a study on the radioactivity and exposure from a highly toxic alpha-radiation emitter polonium Po-210, and beta emitter lead Pb-210 in several species of Boletaceae mushrooms and stir-fried mushroom meals from China. Edible mushrooms can efficiently concentrate some elements in flesh but little is known on highly toxic alpha- and beta emitters. In this study, the absolute values of radioactivity (Bq.kg(-1) dry weight) for Po-210 were in the range 2.0 +/- 2.0 to 308 +/- 9 in fresh species and 22.1 +/- 1.2 to 142 +/- 4 in a ready to eat meals, and for Pb-210 were 3.6 +/- 0.5 to 51.8 +/- 2.9 and 3.0 +/- 0.14 to 9.6 +/- 0.5, respectively. The studied batches of a corresponding species of mushrooms - raw and cooked - were not equivalent regarding the homogeneity of the composition. However the raw mushrooms (ingredient for any cooking), showed greater radioactivity in relation to stir-fried meals, and that can imply on a partial loss of nuclides. A daily portion of 100 g of stir-fried mushrooms could provide Po-210 and Pb-210 radiation in the range 0.2-2.1 mu Sv and 0.02-0.06 mu Sv, respectively. Assessed, the cumulative doses of exposure to Po-210 were 1.4-14 mu Sv in a week period and 75-722 mu Sv at annual timescale, and of Pb-210 amounted at 0.15-0.46 mu Sv and 8.3-24 mu Sv, respectively. The Po-210 can be possibly considered as a major source of ionizing radiation activity for persons with high mushroom meals consumption in SW Asia, while the number of available data is limited.