Abstract
Herbs in Egypt are imported from different countries and widely used in different forms. Owing to their different origins, the measured radioactivity levels show a broad range. For example, the radium concentrations in the studied herbs ranged from 7.71 ± 0.25 Bq/kg in green tea to 115.08 ± 0.49 Bq/kg in gawafa. 137Cs concentrations were found to be quite different from one herb to another, ranging from below the minimum detectable limit to 12.62 ± 0.42 Bq/kg. Some values are much greater than the UNSCEAR reported values for grain products and vegetables. The external exposure and the uptake of naturally occurring radionuclides were studied in terms of the annual effective absorbed dose and the annual ingestion dose, respectively. The herb store workers are externally exposed due to natural radiation in the herbs. The annual effective absorbed dose was calculated as 282.8 µSv for tilia, a dose which is over half the total annual effective dose due to terrestrial radiation (which is 410 µSv). Thus, it is potentially possible to accumulate excess doses from all herbs in the store which constitute a health hazard to the workers. For internal exposure, assuming a 1 kg/year annual intake for each herb, the annual ingestion doses are lower than the global value and can be further diminished if herbs with lower concentrations of radionuclides are consumed. [PUBLICATION ABSTRACT]