Uranium, polonium and thorium in infant formulas (powder milk) and assessment of a cumulative ingestion dose

Levels of naturally occurring radionuclides in foods from the first German total diet study

Although natural radionuclides are always present in foods, information about the levels is scarce. The diet-related exposure to radiation is, however, dependent on the radionuclide content of respective food items. In this study, the levels of the naturally occurring radionuclides lead-210 (Pb-210), uranium-234 (U-234), uranium-238 (U-238), radium-226 (Ra-226) and radium-228 (Ra-228) were investigated in over 200 foods as part of the first German total diet study. Radioanalytical techniques and measurements were applied for determination. The natural radionuclide activity concentrations obtained were generally low compared to international data compilations. Together, Ra-228 and Ra-226 mostly dominated the levels of activity concentrations. Of all Ra-226, Ra-228 and Pb-210 results, between 1 % and 19 % exceeded the International Atomic Energy Agency (IAEA) guidance level for food products of 0.1 Bq/kg or 1 Bq/kg. The received activity levels for both U-234 and U-238 were found to be below the suggested IAEA guidance level of 10 Bq/kg. The radionuclide activity ratios of Ra-226/Ra-228, U-234/U-238 and Pb-210/Ra-226 of the foods were examined as well. In particular, it was found that the average Ra-226/Ra-228 ratio in all main food groups was substantially lower than the average Ra-226/Ra-228 ratio in soils. An isotope dependent transfer of Ra-226 and Ra-228 from soil to plants and foods is suggested to explain the difference. The obtained data set will be a valuable contribution to international data collections and thus help to a better understanding of the public exposure to natural radionuclides from the food consumption in the future.

Study of Polonium (210Po) Activity Concentration in Fruit Wines Derived from Different Locations in Poland

This study aimed at assessing the activity concentration and the annual effective dose of polonium-210 (210Po) in fruit wines derived from four locations in Poland (Warmian−Masurian, Podlaskie, Lubelskie and Małopolskie voivodeships). The fruit wines differed significantly (p < 0.05) in 210Po activity depending on the production site, with the Małopolskie site having the highest activity (61.4−221.4 mBq/L) and the Podlaskie having the lowest (3.5−97.1 mBq/L). The site differentiation was due to environmental conditions—soil parameters (uranium concentration), precipitations and terrain characteristics, e.g., the proximity of the lakes. The increased activity concentration of 210Po in samples from Małopolska compared with the other sites probably derived from the environment polluted with aqueous wastes and particulate air pollution. The annual effective dose due to the ingestion of fruit wines ranged from 0.112 to 1.214 µSv/year. These levels of exposure are safe according to the WHO criterion (0.1 mSv per year for ingestion) and to the IAEA reference level for public exposure including food (1 mSv per year). Summing up, the data obtained provide information on the activity concentration of 210Po in fruit wines and increase databases on the natural radioactivity of foodstuffs. Future work is needed to examine 210Po activity in samples from all vineyard regions in Poland.

The use of total diet study for determination of natural radionuclides in foods of a high background radiation area

The activity concentrations of ⁴⁰K, ²¹⁰Pb, ²¹⁰Po, ²²⁶Ra, ²²⁸Ra, ²²⁸Th, ²³⁰Th, ²³²Th, ²³⁴U, and ²³⁸U were determined in 82 food samples, grouped into 20 food groups according to the Brazilian Total Diet, which reflects the dietary habits of a population, for the rural and urban areas of Poços de Caldas city, a High Background Radiation Area. The highest activity concentration found in the food samples was due to ⁴⁰K being present in all types of food. Among the other radionuclides, high activity concentrations were found for ²¹⁰Pb in beans and salt, ²¹⁰Po in fish, ²²⁶Ra and ²²⁸Ra in nuts and seeds. The main food groups that contributed most to the effective dose, in urban and rural regions, were beans and beverages. The effective doses, due to the ingestion of the analysed food groups, were of 0.44 and 0.60 mSv y^-1 and the lifetime cancer risks were 1.6 × 10^-3 and 2.3 × 10^-3 for the urban and rural Poços de Caldas population, respectively.

Assessment of intake of 210Po and 210Pb isotopes from cow's milk in Poland

Milk has been known for its nutritional properties for centuries and is often the staple of the diet in many countries. Therefore, monitoring of milk composition seems to be a relevant task as it was the purpose of this study to compare levels of ²¹⁰Po and ²¹⁰Pb in several Polish voivodeships. The methodology was based on mineralization, loss on an inorganic matrix and concentration measurement on an alpha spectrometer. The concentrations of ²¹⁰Po and ²¹⁰Pb in collected milk samples were measured using alpha spectrometry and calculations, respectively. The results showed that the lowest concentration of ²¹⁰Po is 2.8 ± 0.2 mBq l^-1 and the highest is 56.3 ± 0.7 mBq l^-1 while the ²¹⁰Pb concentrations are in the range from 2.8 ± 0.2 to 44.0 ± 1.7 mBq l^-1. The associated annual effective doses for adults jmrange from 3.5 ± 0.1 to 11.0 ± 0.2 µSv a^-1 for ²¹⁰Po and from 2.0 ± 0.1 to 5.0 ± 0.1 µSv a^-1 for ²¹⁰Pb. The lowest doses were noticed in Kuyavian-Pomeranian Voivodeship and the highest values were found in Lesser Poland Voivodeship. The results show that the annual effective dose in individual provinces is not dangerous to health. However, there are significant differences between highly and lowly industrialized voivodeships.

Study of Alpha and Beta Radioactivity of Clay Originating from Radionuclides Belonging to the 238U and 232Th Families: Doses to the Skin of Potters

ABSTRACT

Pottery objects are presently more and more used for decoration in homes and hotels. To assess radiological hazards to potters, 238U, 232Th, 222Rn, and 220Rn radionuclides were analyzed in different clay body samples used for pottery production by means of CR-39 and LR-115 II track detectors. Data obtained were compared to those gotten by means of isotope dilution mass spectrometry. Annual equivalent doses to the skin of potters resulting from the energy loss of alpha-particles emitted by the radionuclides of the 238U and 232Th radioactive families were evaluated. Estimates of the annual equivalent doses to the skin of potters due to the emitted alpha-particles ranged between 6.45 mSy y-1 cm-2 and 17.50 mSy y-1 cm-2 and between 1.87 mSy y-1 cm-2 and 5.33 mSy y-1 cm-2, respectively. Annual equivalent doses received by the skin of potters due to beta-particles (β-) emitted by the radionuclides of the 238U and 232Th series inside the studied clay body samples were determined. Alpha equivalent doses to the skin of potters resulting from the diffusion of 222Rn and 220Rn gases present in the studied clay body samples were calculated. A total maximum annual equivalent dose of 23.0 mSv y-1 cm-2, resulting from the energy loss of alpha and beta minus particles emitted by the radionuclides of the 238U and 232Th series, was found for potters working 8 h d-1(6 d wk-1, 49.28 wk y-1).

ASSESSMENT OF THE RADIOACTIVITY OF GAMMA EMITTERS IN BABY FORMULA FOR DIFFERENT AGE GROUPS AND BABY CEREAL CONSUMED IN JORDAN

In the present work, different brands of baby formula and cereal consumed in Jordan were analyzed for their radioactivity content. The activity concentrations of 40K varied with the designated age group in formula with the average concentrations being (in Bq/kg): 160.2 ± 33.5, 219.0 ± 35.0 and 265.2 ± 56.3 for the age groups of 0-6 months, 6-12 months and 1-3 years, respectively. 226Ra was not detected in any of the samples, while 232Th was detected in nearly half the samples with concentrations ranging from 0.22 to 0.82 Bq/kg. 137Cs was detected in only two samples with concentrations of 0.94 and 3.15 Bq/kg. The concentrations of 40K and 232Th in cereal were in the ranges of 23-294 and 0.49-1.48 Bq/kg, respectively. The resulting committed dose was assessed and found in the range of 154-613 μSv, with insignificant contribution from 137Cs, which is within the worldwide range but generally higher than the worldwide average of 290 μSv.

Determination of Trace Elements in Infant Formulas Available on Polish Market

The aim of this study was to assess the levels of 13 essential and toxic elements (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V, Zn) in the infant formulas, available on Polish market. Selected food samples were of animal (cow- and goat-based milks) and plant (soy-based milk, hypoallergic products, grain porridges) origin. Two analytical techniques, inductively coupled plasma mass spectrometry (ICP-MS) and neutron activation analysis (NAA), have been complementarily applied to analyze elemental content of 16 formulas dedicated for infants between 0 and 8 months. For arsenic determinations, the radiochemical mode of NAA was also used. The daily intake of some micronutrients in the age 0-8 months for non-breastfed infants was estimated and compared with present safety limits. Certified reference materials (CRMs) have been used for the validation of the methods: Non-fat Milk Powder 1549 (National Bureau of Standards-NBS), Soya Bean Flour INCT-SBF-4 (Institute of Nuclear Chemistry and Technology-INCT), Rice Flour SRM 1568b (National Institute of Standards and Technology-NIST).