Ionizing radiation

Ionizing and non-ionizing radiations induce stable radicals in solid matrices. EPR allows a qualitative and quantitative evaluation of such radiation-induced radicals which act as indicators of exposure. A quantitative assessment of the exposure can be obtained by using a calibration curve.

Possible fields of application are:

High-dose irradiation (chilogray order) of foods is a sterilization technology that ensures safety and hygienic quality of food through the reduction of microbial load and the deactivation of pathogenic bacteria.

The analytical methods for the identification of irradiated foods, validated and standardized by CEN, can be subdivided, according to the radio-induced modifications on the food, in chemical, physical and biological methods. Among the validated physical methods, the following three are based on EPR technique:

• EN 1786:1996 (Electron Spin Resonance of hydroxyapatite) applicable to foods containing bone;
• EN 13708:2001 (Electron Spin Resonance of sugars) applicable to foods containing crystalline sugar;
• EN 1787:2000 (Electron Spin Resonance of cellulose) applicable to foods containing cellulose.

Two other physical methods based on stimulated luminescence are available.

Contact: Emanuela Bortolin
☎ +39 06 4990 3634

The primary objective of ionizing radiation therapy is to increase the probability of loco-regional tumor control without causing severe toxicity. This can be achieved through an accurate localization of the dose distribution to the neoplastic volumes, with consequent possibility of increasing the dose prescription. For this purpose it is possible to use stable radicals induced by ionizing radiation in the alanine amino acid. The detection of such radicals by Electron Spin Resonance and the correlation of the amount of such radicals with the absorbed dose allows radiotherapy treatments verification (other matrices used in clinical dosimetry are ammonium tartrate, …).

Other medical dosimetry systems are also available in the area.

Contact: Cinzia De Angelis
☎ +39 06 4990 2248