This paper presents the results of measurements of 99m Tc activity concentrations in indoor air in a nuclear medicine department and resulting estimated 99m Tc intake by medical personnel. 99m Tc air activity measurements were conducted at the Nuclear Medicine Department, John Paul II Hospital, Krakow, Poland, during ventilation–perfusion SPECT lung scans. Technetium from the air was collected by means of a mobile aerosol sampler with a Petryanov filter operating at an average flow rate of 10 dm 3 min −1 . Measured activities ranged from 99 ± 11 to 6.1 ± 0.5 kBq m −3 . The resulting daily average intake of 99m Tc by medical staff was estimated to be 5.4 kBq, 4.4 kBq, 3.0 kBq and 2.5 kBq, respectively, for male technicians, female technicians, male nurses and female nurses. Corresponding annual effective doses were 1.6 µSv for technicians and 1 µSv for nurses. The highest equivalent dose values were determined for extrathoracic (ET) airways: 5 µSv and 10 µSv for nurses and technicians, respectively. It is concluded that estimated annual absorbed doses are over three orders of magnitude lower than the dose limit established in the Polish Atomic Law Act and in recommendations of the International Commission on Radiological Protection for medical staff.

This paper presents results of measurements of 99mTc activity concentration in air and nuclear medical personnel blood during ventilation–perfusion SPECT lung scans. 99mTc activity measurements were conducted at the Nuclear Medicine Department, John Paul II Hospital, Krakow. Technicians and nurses who perform examinations were equipped with personal aspirators enabling air sampling to determine the radiation exposure at their workplaces. Measurements allowed to evaluate the concentration of 99mTc in 14 air samples and it ranged from 7800 ± 600 to 10,000 ± 1000 Bq m−3 for air samples collected by technicians and from 390 ± 30 to 600 ± 40 Bq m−3 for air samples collected by nurses. In addition 99mTc concentrations in blood of medical personnel were determined in 24 samples. For technicians the maximum 99mTc blood concentration levels reached 920 ± 70 Bq L−1 and 1300 ± 100 Bq L−1. In the case of nurses, the maximum estimated activity concentrations were about ten times lower, namely 71 ± 7 Bq L−1 and 39 ± 3 Bq L−1. Although the intakes appear to be relatively high, the resulting annual effective doses are about 34 µSv for technicians and only 2 µSv for nurses.

The main objective of the present publication was to assess the reduction of internal radioactive contamination with 99mTc among medical personnel of nuclear medicine facilities using generally available respiratory tract protection systems. During the current research project, four respiratory tract protection systems were tested by estimation of 99mTc activity levels in blood samples collected from medical personnel. Medical staff were equipped with a disposable surgical mask, a half mask with gas absorbers, a half mask with aerosol absorbers and a half mask with gas absorbers with added Petryanov filter. The presented results indicate that wearing only a disposable surgical mask may significantly reduce radioactive internal contamination among medical personnel and improve their safety in the workplace. The best results of reduced 99mTc concentration in the blood were achieved by the use of a half mask with gas absorbers with added Pertryanov filters and a half mask with aerosol absorbers, where the reduction factors were estimated at 90% and 80%, respectively. Respiratory tract protection systems should become standard equipment for medical personnel performing ventilation–perfusion SPECT lung scans.

Nuclear medicine staff are constantly exposed to low doses of ionizing radiation. This study investigated the level of genotoxic effects in hospital employees exposed to routinely used 131I and 99mTc in comparison with a control group. The study compared the results of physical and biological monitoring in peripheral blood lymphocytes. The effects of confounding factors, such as smoking status and physical activity, were also considered. Physical dosimetry monitoring revealed differences in the individual annual effective dose as measured by finger ring dosimeter and whole-body dosimeter between the 131I- and 99mTc-exposed groups. The DNA damage studies revealed differences between the groups in terms of excess premature chromosome condensation (PCC) fragments and tail DNA. Physical activity and smoking status differentiated the investigated groups. When assessed by the level of physical activity, the highest mean values of tail DNA were observed for the 99mTc group. When assessed by work-related physical effort, excess PCC fragments were significantly higher in the 131I group than in the control group. In the investigated groups, the tail DNA values were significantly different between non-smokers and past or current smokers, but excess PCC fragments did not significantly differ by smoking status. It is important to measure exposure to low doses of ionizing radiation and assess the potential risk from this exposure. Such investigations support the need to continue epidemiological and experimental studies to improve our understanding of the mechanisms of the health effects of radionuclides and to develop predictive models of the behavior of these complex systems in response to low-dose radiation.