Ca-DTPA or Zn-DTPA was injected subcutaneously to pregnant mice once a day for 5 consecutive days from day 13 to 17 of gestation. Maternal and fetal livers were collected 20 hours after the final injection of DTPA, and essential metal contents in the liver samples were determined by PIXE. Both Ca-DTPA and Zn-DTPA did not affect essential metal contents in the maternal liver, but Ca-DTPA significantly decreased copper and zinc contents in the fetal liver to 2/3 and 1/2 of the control value, respectively. Zn-DTPA did not affect fetal zinc content, but it decreased that of copper. It could not be determined whether DTPA affected fetal manganese content because the fetal liver contained no detectable amount of manganese.
An incineration system was constructed which were composed of a combustion furnace (AP-150R), a cyclone dust collector, radioisotope trapping and measurement apparatus and a radioisotope storage room built in the first basement of the Radioisotope Center. Low level radioactive samples (LLRS) used for the combustion experiment were composed of combustible material or semi-combustible material containing 500 kBq of99mTcO4or 23.25 kBq of131INa. The distribution of radioisotopes both in the inside and outside of combustion furnace were estimated. We measured radioactivity of a smoke duct gas in terminal exit of the exhaust port. In case of combustion of LLRS containing99mTcO4or131INa, concentration of radioisotopes at the exhaust port showed less than legal concentration limit of these radioisotopes. In cases of combustion of LLRS containing99mTcO4or131INa, decontamination factors of the incineration system were 120 and 1.1, respectively.