Radiation doses caused by environmental contamination

In this chapter dose commitments are estimated from the radionuclide concentrations reported in the previous chapters of this report. The external dose from the accumulated caesium-137 deposition on the ground is about 1 mrad per year in Finland. In 1977 about 0.5 mrad was received from short-lived nuclides deposited on the ground. The intake of radionuclides through food ingestion in 1976 and 1977 added about 2 mrad each year from strontium-90 and about 1 mrad each year from caesium-137 to the dose commitment. Thyroid doses of a few mrad to the infant thyroid were received from iodine-131 in milk on two occasions in October 1976 and October 1977. The dose to the lungs from inhalation of radionuclides in the air was less than 1 mrad in 1976 and 1977 together. (author)