The concentrations of (238)U and (226)Ra were determined in different foodstuffs purchased from markets in Tehran. Determinations of the radionuclides have been carried out using alpha spectrometry technique, on samples of egg, lentil, potato, rice, soya, spinach, tea and wheat. Average concentrations of natural radionuclides and foodstuff consumption rate were used to assess annual intake and based on intake values, the annual effective ingestion dose has been estimated for Tehran city residents. The measurement results show that soya has the maximum concentration of (238)U equal to 15.6 +/- 2.6 mBq kg(-1) and tea has the maximum concentration of (226)Ra equal to 1153.3 +/- 265.3 mBq kg(-1). Besides, the maximum annual effective dose from (238)U and (226)Ra were assessed to be 2.88 x 10(-2) +/- 7.20 x 10(-3) and 2.15 +/- 0.54 muSv, respectively, from wheat samples.

Thirty-eight different milk and milk powder samples from Tehran-Iran were collected and analyzed for 90 Sr activity using a method in which the daughter product of 90 Sr decay ( 90 Y) was extracted by tributyl phosphate from ashed milk. 90 Y was then back extracted with water, and oxalate was precipitated . Following the sample analyzing, beta counting was performed with an ultralow-level liquid scintillation spectrometer. The quality control and assurance of the method were obtained by standard samples prepared with an IAEA-certified reference material. The mean determined 90 Sr activity concentration in the analyzed milk and milk powder (0.225 ± 0.042 and 0.216 ± 0.024 Bq kg -1 , respectively) showed that the radioactivity concentration in our samples was too low to induce biological hazards. These data can provide useful information of the background level of contamination, which in turn can be used in the following environmental monitoring programs.

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