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Biomedical subjects

C Nuccetelli

Publications and source records attributed to C Nuccetelli.

8 recordsLinked to original sources
PubMed2001

Radioactivity in building materials: room model analysis and experimental methods.

First, models (room models) published in the international literature allowing the exposure to gamma radiation indoors due to building materials to be assessed are reviewed and discussed. For one of them, a sensitivity analysis concerning the effect of changing the parameters (e.g. dimensions of the room, thickness and density of the walls, etc.) used in calculations is performed. Second, a method is proposed for calculating the activity concentration in the walls of a room using: (a) the measured absorbed dose rate in air in the room; (b) the contributions of natural radionuclides (238U, 232Th and 40K) to the absorbed dose rate in air assessed by means of gamma spectrometry indoors; and (c) the specific dose rate (nGy h(-1) per Bq kg(-1)) of natural radionuclides, for the chosen room geometry, calculated with the room model.

Air Pollution, Indoor↗
PubMed2001

In situ gamma spectroscopy to characterize building materials as radon and thoron sources.

In situ gamma spectroscopy is widely utilized to determine the outdoor gamma dose rate from the soil and to calculate the natural and artificial radionuclide concentration and their contribution to the dose rate. The application of in situ gamma spectroscopy in indoor environments can not supply quantitative information about activity concentration of radionuclides in building materials, but this technique can provide interesting information about building materials as radon source. In fact, a method based on analyses of gamma spectra data has been developed by the authors to provide, in field, quantitative estimation of disequilibrium in 226Ra and 228Ac sub-chains due to 222Rn and 220Rn exhalation. The method has been applied to data of gamma spectroscopy measurements carried out with HPGe detector (26%) in seven dwellings and one office in Rome. The first results of the data analysis show that, as regards especially the 226Ra sub-chain disequilibrium, different building materials (tuff, concrete, etc.) can show very different characteristics. If, in addition to the spectrometric data, other indoor environment parameters (indoor gamma dose rates, room dimensions, wall thickness, etc.) (Bochicchio et al., Radiat Prot Dosim 1994;56(1-4):137-140; Bochicchio et al., Environ Int 1996a;22:S633-S639) are utilized in a room model, an evaluation of 226Ra, 228Ac and 40K activity concentration and an indication of the exhalation features, by means of estimation of exhaled 222Rn activity concentration, can be achieved.

Journal Article↗
PubMed2001

Experimental and measurement issues in natural radioactivity.

The paper deals with some open experimental problems in the field of natural radioactivity. Its aim is to stimulate discussion on the type of research efforts needed in the field and to be planned for the future. The review, which makes no claims to completeness. analyses some issues in gamma spectrometry of natural radionuclides, and the measurement of natural radioactivity in non-nuclear industries and of 222Rn and 220Rn concentration in air.

Background Radiation↗
PubMed1999

Prenatal exposure to ionizing radiation: sources, effects and regulatory aspects.

Knowledge and awareness of physicians and the general public concerning the risks of prenatal exposure to ionizing radiation are important when developing a correct attitude to ionizing radiation. This is particularly important in the justification of medical diagnostic exposure of pregnant women and in case of possible accidents. The present paper reviews the most recent data on the effects of prenatal exposure to ionizing radiation reported in the scientific literature and in documents of international organizations dealing with this subject. Potentially significant exposure for women of childbearing age in medical diagnostics, working conditions and environmental contamination following the Chernobyl accident are reported. Some examples of doses associated with medical exposure in the course of diagnostic examinations with X-rays and radiopharmaceuticals, and occupational exposure in workplaces are given. Lastly, the regulatory aspects of the European Union directives and the Italian legislation on medical and occupational exposure of women during pregnancy or in reproductive age are reviewed.

Dose-Response Relationship, Radiation↗
PubMed1999

[New aspects in the evaluation of risk factors for fetal development].

Much knowledge concerning the effects of xenobiotics on prenatal development derive from experimental studies, which are generally performed on laboratory animals according to standardized protocols. Conventional in vivo studies should be integrated by other models within a scientifically-based risk assessment strategy. The paper reviews a few in vitro and/or in vivo approaches: identification of critical effects through the characterization of the pathogenesis as well as the use of dose-response relationships; alternative models to identify reproductive risks from single substances and/or mixtures present in the environment; interactions between in vitro and in vivo studies in the risk assessment of solvents: embryonic metabolism in teratogenicity; interactions between experimental and epidemiological studies to understand the pathogenesis of embryolethality; risk assessment of the effects of prenatal exposure to ionizing radiations.

Animals↗
PubMed1996

Results of the representative Italian national survey on radon indoors.

A representative national survey on population exposure to radon in Italian dwellings was carried out from 1989 to 1994, with the co-operation of the National Health Service. The measurements were performed by 19 Regional Laboratories, all using the same techniques and protocols. A stratified, two-stage sampling procedure was used to sample families. The sampled families were approached door-to-door to maximize response. To optimize the quality of the measurements, two dosimeters, each containing two alpha track detectors, were placed together in one room (typically the bedroom) for two consecutive 6-mo periods. The distribution of annual radon concentration was derived from measurements in 4,866 dwellings. The average value is 75 Bq m(-3) and the fractions of dwellings above the reference levels of 150, 200, 400, and 600 Bq m-3 are 8.7%, 4.7%, 1.0%, and 0.2%, respectively. The geometric mean is 57 Bq m-3 while the geometric standard deviation is 2.0. The average values in the Italian Regions fall within the 20-120 Bq m-3 range. When the average radon concentration is examined vs. story, building materials seem to play a significant role. The average lifetime risk of lung cancer for chronic radon exposure of Italian population at home would be about 5 x 10(-3), using the risk factor proposed by the ICRP in 1993.

Air Pollutants, Radioactive↗