Maja Bronzović

Institute for Medical Research and Occupational Health, Zagrabia, Grad Zagreb, Croatia

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Publications (10)8.2 Total impact

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    ABSTRACT: The contents of natural radionuclides (radium, uranium and potassium) were measured in the area of a phosphate fertilizer factory in central Croatia, as a part of extended and still ongoing monitoring program of radioactive contamination of human environment in Croatia that is performed by the Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb. Activity concentrations in all analysed media (waste water, trickling water from piezometers, phosphogypsum deposit and final products) considerably fluctuated, especially in phosphogypsum and waste water. Mean (226)Ra activity concentration in waste phosphogypsum was measured to be 483+/-190 Bqkg(-1). Based on that value, it was estimated that 4 million m(3) of phosphogypsum that have been deposited up to now contain about 4.3 x 10(12) Bq, i.e. about 200 g of (226)Ra. However, effective dose for an adult that would be incurred by consumption of water from nearby wells was estimated to be 5.3+/-1.3 microSv. The results show that (226)Ra activities cause effective doses, which are below the recommended maximum as the estimated annual (226)Ra effective dose does not exceed 0.1 mSv as recommended by the World Health Organization.
    Journal of Hazardous Materials 07/2008; 162(2-3):1199-203. · 3.93 Impact Factor
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    ABSTRACT: This paper presents a model of continuous exposure to 226Ra by water consumption over a 55-year period. The effects of 226Ra concentration in drinking water were investigated. Reaching the peak at the age of 16, the assessed effective dose has shown that children are more sensitive to radiation than adults. It has been found that consumption of 226Ra-rich water during certain period of life increases consequent effective doses. The earlier the exposure, the higher amount of 226Ra could be retained causing the higher values of effective dose later in life. However, long-term exposure to 226Ra in drinking water as well as consumption of 226Ra-rich water during a certain period of life does not indicate the appearance of malignant diseases in the year of exposure and later in adults.
    Journal of Environmental Science and Health Part A 06/2007; 42(6):817-23. · 1.25 Impact Factor
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    ABSTRACT: Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb has been conducting systematic investigations of radioactive contamination of the Croatian environment by anthropogenic fission products as well as by naturally occurring radioactive material (NORM) since 1963. Several critical sites in Croatia were identified for NORM, that is, for slag and ash repositories from coal-fired power plants and phosphogypsum repository from a mineral fertilizer production plant. As the coals and phosphate ores contain naturally occurring radionuclides, especially the members of the uranium and thorium radioactive chains, utilising these materials in various industries only enhances their natural radioactivity in residual waste. Consequently, the resulting activity concentrations of natural radionuclides in waste material could be several times higher than in the adjacent soil. These deposited materials pose permanent risk of radiation exposure due to the long physical half-life of natural radionuclides (e.g., T 1/2 = 1600 years for 226Ra). Results of scientific investigations related to natural radioactivity are used in the recovery of slag and ash repositories and landfills, as well as in establishing regulatory criteria targeting import of coal and phosphate ores. In consequence, recently measured activity concentrations of natural radioactivity in imported materials used nowadays in coal-fired power plants are significantly lower than in previously used raw materials. Therefore, slag and ash can be used as additive materials in cement production.
    Archives of Industrial Hygiene and Toxicology 10/2006; 57(3):333-8. · 0.67 Impact Factor
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    Maja Bronzović, Gordana Marović
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    ABSTRACT: Today, bottled and tap drinking water mainly originates from underground waters which might contain considerable amounts of naturally occurring radionuclides. One of the most toxic radionuclide in drinking water is 226Ra. Following the metabolism of calcium, it could be deposited into the bone where, in sufficient amount, it could cause bone sarcoma. Although current drinking water preparation techniques are not specifically designed for 226Ra removal they can reduce certain amounts of 226Ra. This paper presents the efficacy of standard water preparation processes (granular activated carbon, green sand and fixed-leaf filtrations) currently used by Zagreb water supply and two Croatian water bottlers in removing 226Ra. Compared with other studies, the results of our study show low to moderate efficacy in lowering the 226Ra concentration in drinking water. Even so, 226Ra concentrations still comply with the recommendation of the Word Health Organisation (WHO) and with Croatian legislation.
    Archives of Industrial Hygiene and Toxicology 07/2006; 57(2):165-70. · 0.67 Impact Factor
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    Maja Bronzović, Gordana Marović, Mladen Vrtar
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    ABSTRACT: This paper presents a new method for calculating the effective dose of 226Ra regularly ingested with drinking water over a long period of time. The method is based on the assessment of cumulated 226Ra activity in the fraction retained in the whole body at time t (in days) after intake [so called m(t) value]. For modelling, simulation, and visualisation of the continuous intake of 226Ra by drinking water, we used the Simulink program package integrated with the Matlab. The dose assessment was performed for 226Ra activities of 5 mBq L(-1), 50 mBq L(-1), 1000 mBq L(-1) and 5000 mBq L(-1). The results suggest that 226Ra activities above 1000 mBq L(-1) produce effective doses which are below the recommended maximum. However, the potential effect of 226Ra activities of this extent is still unknown in children.
    Archives of Industrial Hygiene and Toxicology 04/2006; 57(1):39-44. · 0.67 Impact Factor
  • Source
    Maja Bronzović, Gordana Marović, Mladen Vrtar
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    ABSTRACT: This paper presents a new method for calculating the effective dose of 226Ra regularly ingested with drinking water over a long period of time. The method is based on the assessment of cumulated 226Ra activity in the fraction retained in the whole body at time t (in days) after intake [so called m(t) value]. For modelling, simulation, and visualisation of the continuous intake of 226Ra by drinking water, we used the Simulink® program package integrated with the Matlab®. The dose assessment was performed for 226Ra activities of 5 mBq L-1, 50 mBq L-1, 1000 mBq L-1 and 5000 mBq L-1. The results suggest that 226Ra activities above 1000 mBq L-1 produce effective doses which are below the recommended maximum. However, the potential effect of 226Ra activities of this extent is still unknown in children.
    Archives of Industrial Hygiene and Toxicology (arhiv@imi.hr); Vol.57 No.1. 01/2006;
  • Source
    Maja Bronzović, Gordana Marović
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    ABSTRACT: Today, bottled and tap drinking water mainly originates from underground waters which might contain considerable amounts of naturally occurring radionuclides. One of the most toxic radionuclide in drinking water is 226Ra. Following the metabolism of calcium, it could be deposited into the bone where, in sufficient amount, it could cause bone sarcoma. Although current drinking water preparation techniques are not specifically designed for 226Ra removal they can reduce certain amounts of 226Ra. This paper presents the efficacy of standard water preparation processes (granular activated carbon, green sand and fixed-leaf filtrations) currently used by Zagreb water supply and two Croatian water bottlers in removing 226Ra. Compared with other studies, the results of our study show low to moderate efficacy in lowering the 226Ra concentration in drinking water. Even so, 226Ra concentrations still comply with the recommendation of the Word Health Organisation (WHO) and with Croatian legislation.
    Archives of Industrial Hygiene and Toxicology (arhiv@imi.hr); Vol.57 No.2. 01/2006;
  • Maja Bronzovic, Gordana Marovic
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    ABSTRACT: Water may present a source of prolonged exposure to naturally occurring radionuclides. One of the most frequently occurring radionuclides in natural mineral and spring waters is 226Ra and its decay products. The contribution of drinking water to the total exposure is very small, at about 5% of the average effective dose attributable annually to natural background radiation, but that exposure contributes to the risk of adverse health consequences. In this study the mean values of 226Ra concentration determined in natural mineral and spring bottled waters range from 6 to 412 mBq L(-1), which is in accord with Croatian legislation. 226Ra effective doses per year from spring water consumption range up to 86 microSv, while 226Ra effective doses per year from mineral water consumption show much higher values. The highest 226Ra effective doses per year from mineral waters consumption, which are up to seven times higher than the dose recommended by WHO (100 microSv), were found in infants and teens. Based on this study, drinking of certain brands of bottled mineral water is not recommended for these age groups because assessed 226Ra effective doses per year exceed the recommended limits. From other research it is known that testosterone appears in elevated concentration during these life periods and affects bone calcification. Therefore, testosterone could affect the retention of 226Ra into the bone. To make more precise conclusions further research is necessary. Adults and especially elderly people are much less susceptible to the presence of 226Ra. According to the results obtained in this study, 226Ra effective doses per year assessed for these age groups were considerably lower (i.e., 10 microSv).
    Health Physics 06/2005; 88(5):480-5. · 1.02 Impact Factor
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    ABSTRACT: Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb has been conducting systematic investigations of radioactive contamination of the Croatian environment by anthropogenic fission products as well as by naturally occurring radioactive material (NORM) since 1963. Several critical sites in Croatia were identified for NORM, that is, for slag and ash repositories from coalfired power plants and phosphogypsum repository from a mineral fertilizer production plant. As the coals and phosphate ores contain naturally occurring radionuclides, especially the members of the uranium and thorium radioactive chains, utilising these materials in various industries only enhances their natural radioactivity in residual waste. Consequently, the resulting activity concentrations of natural radionuclides in waste material could be several times higher than in the adjacent soil. These deposited materials pose permanent risk of radiation exposure due to the long physical half-life of natural radionuclides (e.g., T1/2= 1600 years for 226Ra). Results of scientific investigations related to natural radioactivity are used in the recovery of slag and ash repositories and landfills, as well as in establishing regulatory criteria targeting import of coal and phosphate ores. In consequence, recently measured activity concentrations of natural radioactivity in imported materials used nowadays in coal-fired power plants are significantly lower than in previously used raw materials. Therefore, slag and ash can be used as additive materials in cement production
    Archives of Industrial Hygiene and Toxicology (arhiv@imi.hr); Vol.57 No.3.
  • Source
    G Marovic, J Kovac, J Sencar, M Bronzovic
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    ABSTRACT: Phosphate ore is starting material for all phosphate products and is the main source of phosphorus for fertilizer production. Prior to processing, phosphate ore contains radium and its decay products, which tends to stay in phosphogypsum produced during the wet phosphoric acid process. Most of the phosphogypsum is considered waste and is disposed at local dump sites or used as by-products. The local dump sites, containing radium are often unprotected and may be a source of contamination to surface or ground waters. Practical implications of this finding are important in view of possible environmental contamination of the area around a fertilizer plant. This study was carried out in the area of a phosphate fertilizer factory in central Croatia, within systematic radioactive measurements of the Croatian environment performed by the Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb. The purpose of this paper was to determine radium specific activity resulting from the phosphate fertilizer production and evaluate possible environmental contamination of the area. Distribution of total radium by the components of the production process was assessed from the values of the radium initial concentrations in raw material, and mean values of radium concentrations measured in waste water, trickling water from piezometers, phosphogypsum deposit and final products.