Solution of wound biokinetic model for estimation of wound/organ retention and urine faecal excretion rates

Although, inhalation is a major route of intake of radioactive material in the body for radiation workers, in case of accidents with sharp tools, activity can get injected through cut/wound. Depending upon the chemical nature of the material, fraction of the activity will retain in the wound site and some fraction will become soluble and get absorbed in the blood or get transferred to lymph nodes. Estimation of total body dose becomes difficult, as activity present in the wound gives local dose. Total internal dose can be estimated by analyzing urinary excretion data as it corresponds to the soluble part of activity. In this study, recently published wound model is solved to estimate the retention fractions for wound as well as for various other important organs and daily urinary and fecal excretion fractions for actinides. The transfer rates for various compartments of the wound model for particle category combined with the biokinetic model of the 238U is solved using MATLAB to predict retained fraction at wound site as well as in various organs. The retained fractions at wound site, kidneys as well as daily urinary excretion fraction (d-1) are found to be same as those given in NCRP report for 238U, particle category. After this validation, it can further be used to calculate retained fraction at wound site and in various organs for other nuclides like Pu and Am for various categories. In case of unknown chemical nature of material, it will be possible to estimate the category of the material by comparing it with the retained fractions for various categories. For example, in case of soluble type, material can behave as weak, moderate, strong and avid. Depending upon the type, activity in the wound will decrease with respect to time, which can be estimated by measuring the wound using actinide wound monitor or other detectors by direct monitoring. Solution of the wound model for various categories as well as by using its biokinetic model, retained fraction for wound and other organs and daily urinary and faecal excretion fractions are predicted. The paper presents the details of the methodology involved in solving the wound biokinetic model and compares the retained and excreted activity with standard reported values