Absorption of environmental polonium-210 by the human gut

Abstract

Current values for the gut absorption factor of polonium-210 (210Po) are based on very few human data, yet the dose due to 210Po is an important component of the dose to man through food as a result of natural sources of radiation. In this study, three male and three female adult volunteers ate supplies of brown crab meat containing natural concentrations of 210Po, which were analysed from sub-samples. Daily urine and faecal samples, taken for 3 days before and up to 3 weeks after ingestion, were also analysed. Values of apparent absorption were derived from the faecal measurements; estimates of the true absorption were derived taking account of endogenous faecal excretion on the basis of existing data for intravenous administration. The results appear to suggest that the gut absorption factor in current use for 210Po (in connection with ingestion in food) should be increased from 0.1-0.3 to about 0.8. The implications for estimates of dose due to this exposure pathway are noted.

Increase of 210Po levels in human semen fluid after mussel ingestion

“…By day 7, most of the ingested 210 Po had been cleared from faeces and urine, in agreement with data reported previously by Hunt and Allington (1993) for brown crab meat ingestion. The dose resulting from the ingestion of the scallop Chlamys varia from the Bay of La Rochelle, France was investigated by Bustamante et al (2002).…”

210Po binding to metallothioneins and ferritin in the liver of teleost marine fish

“…This naturally occurring radionuclide is also responsible for a significant proportion of the radiation exposure of humans to background radiation, in particular, through consumption of seafood (Parfenov 1974, Hunt & Allington 1993, Yamamoto et al 1994, Carvalho 1995a. 210Po is naturally occurring and ubiquitous in our environment, but, due to its radiotoxic properties, special attention has been paid to the possible enhancement of 210Po environmental concentrations which may occur from the inputs of effluents of phosphate-ore processing industries (Germain et al 1992, Pennders et al 1992, Carvalho 1995b, Swift et al 1995.…”

Radionuclides in marine mammals off the Portuguese coast

“…High Po/Pb ratios are a consequence of the preferential 210 Po absorption through gut walls comparatively to 210 Pb, followed by 210 Po accumulation in the internal organs of marine organisms Fowler, 1993, 1994) and in man (Hunt and Allington, 1993).…”

“…Taking into account the available knowledge on 210 Po transfer in marine food chains it seems likely that the diet of marine mammals accounts for the observed 210 Po activity concentrations and the relative enrichment of 210 Po in comparison to 210 Pb (Carvalho, 1995(Carvalho, , 2010Carvalho and Fowler, 1994;Hunt and Allington, 1993). Table 3 Polonium ( 210 Po) activity concentrations (Bq kg À1 AE 1 SD, wet weight) in tissues of marine mammals from several regions.…”