Questionnaires were designed containing questions relating to 222Rn, to know the student’s awareness of the dangers of 222Rn gas. The questionnaire was distributed randomly to 30 students of the fourth stage of both sexes in the departments of the college of science. The survey shows that the 222Rn awareness of fourth-stage students for all departments of the college of science, Mustansiriyah university is scarce.

In this article, internal CRn measure have been carried out in twenty-three locations various rooms and Laboratory of Department Physics in science college in the university of Mustansiriyah. CRn were measure by Rad-7 detector. The results show that, the maximum CRn in indoor rooms was found in Electronics Laboratory (64.9 Bq/m3), whilst the minimum CRn was found in room rapporteur of higher studies (2) / Department of Physics (24.3 Bq/m3), which was lower (200-300Bq/m3) indoor air and the value of parameters hazard indices were lower than the value of permissibility limit.

In the present work, three radioactive elements of radium were used to produce radon gas and 222Rn was measured by three different techniques (Rad-7 detector, Scout detector and CR-39 detector). It was found that the 222Rn gas measured by Rad-7 detector is closer to the real readings than other detectors.