Other food rich in potassium (and therefore in 40K) include potatoes, kidney beans, sunflower seeds, and nuts.[18][19] Brazil nuts in particular are not only rich in 40K but may also contain significant amounts of radium, which have been measured at up to 444 Bq/kg (12 nCi/kg).[20][21] Some types of table salt can contain trace amounts of radium;[22] while tobacco contains traces of thorium, polonium and uranium.[23][24]