Natural ventilation considerations for radon prone areas of Ramsar

In Iran, architectures are often unaware of the risk of radon inhalation and how to reduce radon levels. Furthermore, radon considerations are not implemented in construction methods, construction materials and building utilization by regulatory authorities. In this study after reviewing the meteorological changes of Ramsar over the past 50 years [1955-2005], a novel design for constructing dwellings in radon prone areas is introduced. Out of building interventions such as planting wind-tunnel-making trees will be discussed in another paper. Ramsar soil samples with 4 levels of specific activities [extremely hot, severely hot, very hot, and hot] were placed in a model house. Radon level monitoring was performed by using a PRASSI portable radon gas survey meter. For extremely hot soil samples, the radon levels inside the model house when windows were closed for 24 hours were 1615 +/- 516 Bq/m3. When windows which were in the wind direction or opposite the wind direction were opened for 24 h, the radon level decreased to 89 +/- 286 and 139 +/- 314 Bq/m3, respectively. Interestingly, when crossed windows were opened for the same duration, Radon level was 144 +/- 92 Bq/m3. In cold seasons, when windows are usually closed, Chimney effect reduced the radon level to 323 +/- 641. For severely hot, very hot and hot soil samples, natural ventilation-based interventions effectively reduced the radon level. Results obtained in this study clearly show that natural ventilation-based simple cost-effective interventions can significantly reduce the radon concentration in radon prone areas of Ramsar

[ effects of low doses of diagnostic x-rays on cellular and humoral immunological responses in balb/c mice]

The immunosuppressive effects of high doses of ionizing radiation have long been known. Recently, in human and experimental animal models it has been reported that low dose radiation may have immunostimulatory effects. The aim of this study was to evaluate the effects of low doses of diagnostic X-ray on cell mediated and humoral immune responses in a Balb/c animal model. In this experimental study, three groups of male Balb/c mice were exposed once, twice and three times to 30 mGy X-ray radiation. Two to 4hrs after the irradiation, the delayed type hypersensitivity [DTH] and humoral responses to sheep red blood cell [SRBC] were measured and compared to the responses of sham and control groups. The mean titer of anti-SRBC antibodies in two-times irradiated [74.66 +/- 26.12] and three-times irradiated [128 +/- 70.1] groups were significantly higher than those of the control [26.66 +/- 8.26] and sham [28.8 +/- 20.86] groups [p<0.001]. However, no significant differences were observed between the mean titer of anti-SRBC antibodies in one-time irradiated [22.4 +/- 8.76] and either control or sham groups. Similarly, comparing DTH responses showed that the differences between either two-times irradiated [12.2 +/- 3.9] or three times-irradiated [6.9 +/- 3.7] and control [4 +/- 0.2] or sham [4.3 +/- 3] groups was statistically significant [p<0.001]. Theses results showed that twice and three-times irradiated mice demonstrated significant stimulatory effects on both DTH and antibody responses. However, one-time irradiated animals did not exhibit any bio-positive effect on DTH and humoral responses. Moreover, no statistically significant difference was observed between the DTH and antibody responses of two-times and three-times irradiated mice