Concentrations of selenium, barium, and radium in Brazil nuts

The concentrations of selenium, barium, and radium were determined in Brazil nuts grown in four regions: Brazil, Bolivia, Peru, and an unknown locality assigned to northern South America. Results indicated that, regardless of geographic origin, all nuts contained measurable amounts of selenium, barium, and radium. The concentration range of Se (2–20 μg/g) and that of Ba (96–1990 μg/g) each varied by more than an order of magnitude in the nuts, while 226Ra (17–27 mBq/g) and 228Ra (18–31 mBq/g) activities were comparable and within a factor of two of one another. The greatest concentrations of the elements were measured in nuts from Bolivia, for Ba; Brazil, for Ra; and northern South America, for Se. Only the northern South American nuts contained 137Cs.