Assessment of the potential bioaccessibility of 210Po, 232Th and uranium radionuclides from snus to consumers.

Snus is an oral moist smokeless tobacco product with high nicotine content, provided in small pouches or loose form to be placed under the lip. It is the most common way to consume tobacco in Sweden, due to the perception of being less harmful. However, snus contains carcinogenic ingredients such as tobacco-specific nitrosamines and high radiotoxicity radionuclides. The current study had investigated the radioactivity levels of 210Po, 232Th, 234U and 238U in 16 Swedish snus products as well as the capacity of saliva to extract them from snus. The higher activity concentration was measured for 210Po, ranging between 2 and 6 mBq/g with an average activity concentration of 4 ± 1 mBq/g. In the case of 232Th and uranium radionculides the activity concentration ranged between 0.1 and 0.7 mBq/g with an average value of 0.2 ± 0.1 mBq/g for uranium radionuclides and 0.3 ± 0.1 mBq/g for 232Th. For the first time, bioaccessibility of other alpha emitters different to 210Po from snus consumption has been determined. However, the results of the study highlighted that 210Po is the alpha emitter with higher contribution to dose exposure for snus consumers, being neglectable the contribution from 232Th and uranium radionuclides.