Polonium-210 and lead-210 in food and tobacco products: a review of parameters and an estimate of potential exposure and dose

Abstract

Food-chain transport of Pb-210 and Po-210 from soil to edible plant parts and from animal feed to meat and milk were evaluated from a review of literature. The degree of transfer was characterized by estimating concentration factors (unweighted arithmetic means) as well as the transfer coefficients B v , B r (unweighted geometric means), f m and f f (unweighted arithmetic means). Global dietary intake of Pb-210 and Po-210 was also summarized, and 50-year dose estimates to target organs calculated. The greatest estimated ingestion doses were those to populations with large dietary complements of animal protein in the form of seafood (Japan) or caribou/reindeer muscle and organ meats (Arctic Eskimos and Lapps). The magnitude of this latter source illustrates the importance of simple food chains in generating significant exposures to populations dependent upon them. The origin and magnitude of inhalation exposure and dose from tobacco products was also assessed. For the majority of internal organs evaluated, the dose resulting from smoking commercially available tobacco products is comparable to or greater than the dose estimates for ingestion of naturally occurring dietary Pb-210 and Po-210. vii distance from supposed sites of release due to the extreme mobility of the noble gas Rn-222 [T ½ = 3.8 d (Kocher, 1977)], an intermediate product of Ra-226 decay. The rapid decay of Rn-222 in the atmosphere generates Pb-210 and Po-210, which are adsorbed by aerosols and returned to earth as surficial deposition or rainout. The degree of potential long-range atmospheric transport in North America has been previously demonstrated for Rn-222 (Travis et al., 1979). Other intermediates in the decay

Concentration levels of 210Pb and 210Po in dry tobacco leaves in Greece

“…A review of the radioactivity levels in cigarettes consumed worldwide (Watson, 1983;Khater, 2004;Peres and Hiromoto, 2002) showed that 210 Po concentration ranged from 3.3 to 31.1 mBq g ÿ1 of dry sample. For comparison two countries are mentioned here, Brazil that produced tobacco with relatively high concentrations in these two radionuclides and Syria that produced tobacco with relatively low concentrations.…”

“…The geographical distribution of tobacco cultivation does not exhibit the level of variation that would allow further statistical study. It has been suggested that other sources for 210 Po and 210 Pb can include road traffic and industry, especially coal-fired power plants (Watson, 1983). Other studies in coastal areas (Carvalho, 1995) explained most of the variation in airborne 210 Po and 210 Pb concentrations by large or synoptic scale air mass transport of continental origin.…”

Review of Russian language studies on radionuclide behaviour in agricultural animals: part 2. Transfer to milk

“…Ng et al (1977) recommend an F m value of 2.6 Â 10 À4 d L À1 based on six balance studies of linked milk and vegetation with a range in F m value of 1.3 Â 10 À5 -7.7 Â 10 À4 d L À1 for stable Pb (assuming 10 kg d À1 (DW) intake) and two radioisotope studies which resulted in values for F m of 2.4 Â 10 À5 and 9.1 Â 10 À6 d L À1 . Rayno (1983) reported ranges in F m value of 2.0 Â 10 À6 e1.2 Â 10 À4 d L À1 based on five studies; McDowell-Boyer et al (1980) reported a mean F m value of 1.0 Â 10 À4 d L À1 based on 14 values, ranging from 2.0 Â 10 À6 to 4 Â 10 À4 d L À1 ; and Watson (1983) reported a mean F m of 1.2 Â 10 À4 d L À1 based on five studies which ranged from 1.8 Â 10 À6 to 4.0 Â 10 À4 d L À1 .…”

Radionuclide content and state of isotopic disequilibrium in some utilized smoking pastes

“…Several studies [1][2][3][4][5][6][7][8][9][10], started in 1960s or earlier, described that 210 Pb and 210 Po, both members of the uranium decay series, are associated with tobacco and deliver high radiation doses to the smokers. Some of these studies reported that the principal mechanism of their incorporation into the tobacco leaves involves uptake into roots from the soil and phosphate fertilizers [8,9].…”