Gamma radiation doses to people living in Western Sweden.

Indoor environments contribute to gamma radiation in the general population. The aims of the present study were to investigate average gamma radiation doses in a rural and an urban area of Sweden, compare indoor dose rates with personal exposure, and study the effects of building characteristics on radiation levels. Radiation was measured with thermoluminescence dosimeters (TLDs). Repeated measurements were performed with TLDs worn by participants (n=46) and placed in their dwellings. Personal dose rates were 0.092microSv/h (rural) and 0.096microSv/h (urban). The mean effective gamma dose rates in dwellings were 0.091microSv/h (rural) and 0.11microSv/h (urban), which are higher than the world average. Dose rates in apartments were higher than in detached houses and higher for concrete than wooden dwellings. Personal dose rates were strongly associated with dwelling dose rates (r(p)=0.68, p<0.01) and could be modelled. Within-participant variability was low.

Vertical migration studies of 137Cs from nuclear weapons fallout and the Chernobyl accident.

The vertical migration of (137)Cs originating from nuclear weapons fallout (NWF) and the Chernobyl accident has been studied at 33 sampling sites in western Sweden. An attempt to describe the present depth distribution with a solution to the convection-diffusion equation (CDE) with a pulse-like fallout event as the initial condition was made. A sum of two CDEs describing the NWF and Chernobyl debris was fitted to the actual depth profiles measured by soil sampling. The fitted depth profiles were used to correct in situ measurements for the actual depth distribution, showing good agreement with the accumulated activities in soil samples. As expected, the vertical migration was very slow and most caesium was still present in the upper soil layers. The ranges of the apparent convection velocity, v, and apparent diffusion coefficient, D, were between 0 and 0.35 cm/year and 0.06 and 2.63 cm(2)/year, respectively.

Chest physiotherapy after coronary artery bypass graft surgery--a comparison of three different deep breathing techniques.

The effectiveness of three deep breathing techniques was evaluated in 98 male patients after coronary artery bypass graft surgery in a randomized trial. The techniques examined were deep breathing with a blow bottle-device, an inspiratory resistance-positive expiratory pressure mask (IR-PEP) and performed with no mechanical device. Pulmonary function and roentgenological changes were evaluated. Four days post-operatively there were significantly decreased vital capacity, inspiratory capacity, forced expiratory volume in 1 second, functional residual capacity, total lung capacity and single-breath carbon monoxide diffusing capacity in all three groups (p < 0.0001). No major differences between the treatment groups were found, but the impairment in pulmonary function tended to be less marked using the blow bottle technique. The Blow bottle group had significantly less reduction in total lung capacity (p = 0.01) compared to the Deep breathing group, while the IR-PEP group did not significantly differ from the other two groups.

Prognostic value of malignant cells in pleural lavage at thoracotomy for bronchial carcinoma.

Despite seemingly radical surgery many patients operated on for bronchial carcinoma will die from their disease. Some patients might benefit from postoperative treatment and a prognostic factor that could identify those with an increased risk for tumor relapse would be of great clinical importance. One possible such factor is the occurrence of malignant cells in pleural lavage performed at operation. To test this hypothesis 224 consecutive patients who had been operated on due to verified or strongly suspected bronchial carcinoma, preoperatively staged as stage I or II, were investigated. After opening the thorax and before manipulation or palpation of the lungs, 300 ml of physiological saline solution was installed into the pleura. After excluding patients who were not radically operated, there remained 138 patients with histologically confirmed lung cancer (carcinoids excluded) and 12.3% showed tumour cells in the washings. Two of 18 patients with metastatic lung disease ( 11%) and one of ten patients with carcinoid tumor also showed malignant cells in the lavage. The patients with lung cancer have been followed for 3 years or until death. After three years 60.2% of those without malignant cells in the pleural lavage were still alive, while this figure was 41.2% in the other group. The difference was not statistically significant. Other factors, such as spread to local lymph nodes, size of tumor, etc. were related to the occurrence of malignant cells in the pleura, and these factors were also better prognostic ones. We conclude that the clinical use of pleural lavage cytology is limited.