Personnel real time dosimetry in interventional radiology.

Interventional radiology and hemodynamic procedures have rapidly grown in number in the past decade, increasing the importance of personnel dosimetry not only for patients but also for medical staff. The optimization of the absorbed dose during operations is one of the goals that fostered the development of real-time dosimetric systems. Indeed, introducing proper procedure optimization, like correlating dose rate measurements with medical staff position inside the operating room, the absorbed dose could be reduced. Real-time dose measurements would greatly facilitate this task through real-time monitoring and automatic data recording. Besides real-time dose monitoring could allow automatic data recording. In this work, we will describe the calibration and validation of a wireless real-time prototype dosimeter based on a new sensor device (CMOS imager). The validation measurement campaign in clinical conditions has demonstrated the prototype capability of measuring dose-rates with a frequency in the range of few Hz, and an uncertainty smaller than 10%.

Sedimentable mineral organic detritus as radioecological indicator.

The sedimentable mineral organic detritus (SMOD) drawn by rivers can be considered an important matrix for the monitoring of contaminants in aquatic environments. In Italy the collection and radioactivity analysis of SMOD has been introduced and standardised in the 80s. However hydrological parameters, like the flow and the amount of suspended matter close to the sampling points, must be considered to improve the methodology. This technique has been applied by the authors since 1992 to monitor the concentration of both 137Cs (following the Chernobyl accident) and 131I (because of possible waste discharge from Perugia University Hospital) along the Umbrian course of the Tiber River. In this paper the results of 137Cs water concentration are presented and discussed in the light of our interpretative working hypothesis based on hydrological parameters. This work allowed us to reduce the number of sampling points without loss of radioecological information.

Evaluation of 137Cs activity in plant drugs and in some phytoderivatives from Chernobyl accident up to present (1986-1994).

The accident to the nuclear power plant of Chernobyl (in April 1986) caused a radioactive contamination in large areas of the majority of European countries. During the first transient time the fall-out phenomenon was the most important method of contamination, particularly from 131I whose relative isotopic abundance with respect to other released radionuclides was very high. Thereafter, 137Cs, owing to its long half-time and its large presence in environmental matrixes and so in the food chain, became the element on which the attention was to be focused. Plant drugs and their derivatives are, at present, of very large alimentary consumption among people. This can cause some problems to human health, so the authors have studied (from 1986 to 1994) the activity of 137Cs in a large number of drugs (about 5000) and in some industrial and home-made officinal products. Some suggestions on the Cs+,K+ ions competition in soil can also be derived.

Uptake of radiocesium by mushrooms.

After the Chernobyl accident in April 1986 the 134Cs, 137Cs and 40K activity of mushrooms of different genera and their corresponding soils from woods located in the province of Umbria (Italy) was determined. The results indicated: a temporally increasing trend for 137Cs up to a "limit value" depending on local fallout in 1986; different cesium concentrations in various mushroom genera; and uptake of potassium from soil that did not appear to compete with cesium uptake. No reliable correlation can be inferred between the cesium content of the soil and those of mushrooms.