Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412).

The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training.

Monitoring of radioactive contamination in Polish surface waters in 2012-2013.

The 90Sr and 137Cs contamination in Polish surface waters has been monitoring since 1994. Surface water samples from six lakes and the Vistula and Oder Rivers were collected in spring and autumn 2012 and 2013. The mean 90Sr and 137Cs concentrations were 3.92 ± 0.40 and 4.49 ± 2.00 mBq L-1, respectively. Correlations were identified between the radionuclide concentrations and meteorological conditions and the original fallout distribution from the Chernobyl disaster. The annual average radionuclide concentrations were not significantly different from the concentrations found between 1994 and 2011. The 137Cs and 90Sr concentrations have been decreasing only slowly.

Certified Reference Material IAEA-446 for radionuclides in Baltic Sea seaweed.

A Certified Reference Material (CRM) for radionuclides in seaweed (Fucus vesiculosus) from the Baltic Sea (IAEA-446) is described and the results of the certification process are presented. The (40)K, (137)Cs, (234)U and (239+240)Pu radionuclides were certified for this material, and information values for 12 other radionuclides ((90)Sr, (99)Tc, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (230)Th, (232)Th, (235)U, (238)U, (239)Pu and (240)Pu) are presented. The CRM can be used for Quality Assurance/Quality Control of analysis of radionuclides in seaweed and other biota samples, as well as for development and validation of analytical methods, and for training purposes.

Daily intakes of 238U, 234U, 232Th, 230Th, 228Th and 226Ra in the adult population of central Poland.

Activity concentration of the uranium and thorium series radionuclides was determined in foodstuffs and drinking water in central Poland. Annual and daily intake for the adult population was estimated from the concentrations determined and average annual consumption of food and water. The daily intakes (in mBq) were 22.1 (238U), 26.5 (234U), 2.38 (232Th), 4.06 (230Th), 11.2 (228Th) and 42.2 (226Ra). The intake of uranium isotopes occurred mainly with water; the main intake of thorium isotopes was with animal products, vegetables, cereals and potatoes, whereas 226Ra entered mainly with animal products, cereals and vegetables. From the intake and dose coefficients, the annual effective doses for the ingested radionuclides were calculated. The annual effective dose was 5.95 microSv, of which 72.4% originated from 226Ra.

The radiological exposure of man from radioactivity in the Baltic Sea.

A radiological assessment has been carried out considering discharges of radioactivity to the Baltic Sea marine environment since 1950. The sources of radioactivity that have been evaluated are atmospheric nuclear-weapons fallout, fallout from the Chernobyl accident in 1986, discharges of radionuclides from Sellafield and La Hague transported into the Baltic Sea, and discharges of radionuclides from nuclear installations located in the Baltic Sea area. Dose rates from man-made radioactivity to individual members of the public (critical groups) have been calculated based on annual intake of seafood and beach occupancy time. The dose rates to individuals from the regions of the Bothnian Sea and Gulf of Finland are predicted to be larger than from any other area in the Baltic Sea due to the pattern of Chernobyl fallout. The dose rates are predicted to have peaked in 1986 at a value of 0.2 mSv year-1. Collective committed doses to members of the public have been calculated based on fishery statistics and predicted concentrations of radionuclides in biota and coastal sediments. The total collective dose from man-made radioactivity in the Baltic Sea is estimated at 2600 manSv, of which approximately two-thirds originate from Chernobyl fallout, approximately one-quarter from atmospheric nuclear-weapons fallout, approximately 8% from European reprocessing facilities, and approximately 0.04% from nuclear installations bordering the Baltic Sea area. An assessment of small-scale dumping of low-level radioactive waste in the Baltic Sea in the 1960s by Sweden and the Soviet Union has showed that doses to man from these activities are negligible. Dose rates and doses from natural radioactivity dominate except for the year 1986 where dose rates to individuals from Chernobyl fallout in some regions of the Baltic Sea approached those from natural radioactivity.

Vertical distribution and flows of lead and natural radionuclides in the atmosphere.

Vertical distributions of radium-226, lead-210, uranium and stable lead were observed in the troposphere and lower stratosphere over Poland at several altitudes between 0 and 15 km in the period 1973-1987. Greatly increased concentrations of stable lead and radium-226 were observed at all altitudes for several years after the Fuego volcano eruption in 1974, and also after the Nevado del Ruiz eruption in 1985. The volcanic eruptions in 1980-1982 contributed to the radium-226 and uranium levels at the higher altitudes. The annual flows of radium-226, lead-210, uranium and stable lead into the global atmosphere, estimated from their long-term average contents in the 0-15 km air layer, are 2.3 x 10(14) Bq, 8.4 x 10(15) Bq, 8.3 x 10(9) g and 3.7 x 10(12) g, respectively. These estimates are similar to those based on concentrations of these nuclides in widely dispersed glaciers in both hemispheres, and on radon-222 exhalation measurements. However, they are higher than estimates based on particulate emissions. The anthropogenic contribution to the total flow of radium-226 into the global atmosphere is approximately 3.7%, for lead-210 0.25%, uranium 17% and stable lead 9.7%.