Activity concentrations and mean annual effective dose from gamma-emitting radionuclides in the Lebanese diet.

Since the primary factor contributing to the internal effective dose in the human organism is contaminated food, the control of radionuclides in food represents the most important means of protection. This study was conducted to determine the levels of the dietary exposure of the Lebanese population to gamma-emitting radioisotopes. The activity concentrations of gamma-emitting radioisotopes have been measured in food samples that represent the market basket of an adult urban population in Lebanon. The artificial radionuclide (137)Cs was measured above detection limits in only fish, meat and milk-based deserts. The most abundant natural radionuclide was 40K (31-121 Bq kg(-1)), with the highest content in fish and meat samples. The annual mean effective dose contributed by 40K in the reference typical diet was estimated equal to 186 microSv y(-1), a value reasonably consistent with findings reported by several other countries.