RELATED GENES IN LUNG CANCER TISSUES ASSOCIATED WITH RESIDENTIAL HIGH RADON EXPOSURE

Objective: To investigate the related genes in lung cancer tissues associated with residential high radon exposure. Methods: Differentially expressed gene fragments in lung cancer and normal lung tissues were discovered by differential display and reverse Northern blot hybridization method. The fragments positive in lung cancer and negative in normal lung tissue were determined. Results: Seven differential displayed fragments were sequenced. One of them named NA7 is 95% homologous with AI208667 in EAT of Genbank. Another fragment named NG2 is up to 98% homologous with five fragments. The remained one CA1 may be a new gene fragment. Conclusion: 3 gene fragments were discovered from lung cancer and normal lung tissues of high radon exposure resident.

Assessment of Radiation Hazard from External and Internal Exposures at Adham and Surroundings in KSA

Twenty-eight environmental samples (eight well water, sixteen granitic rocks and four soils) were collected from different parts of Adham governorate (Adham, Haqal and Al-Jaizah), to assess the radiological hazard and cancer risk from different perspectives. Adham is situated in a valley between two granitic mountain chains, where much of water supply for drinking, house use and irrigation comes from wells collecting water rains. The activity concentrations of naturally occurring 40K, 226Ra and 232Th and radionuclides were measured by gamma-ray spectrometry for all samples using RGK-1, RGU-1 and RGTh-1, IAEA reference standards issued by the International Atomic Energy Agency, for detector efficiency calibration. The measured values were utilized to evaluate the internal and external exposures both outdoors and indoors. Different standard room models were adopted for this respect to evaluate the indoor gamma-rays exposure from construction materials as well as internal exposure to radon gas emanating from them. Radon concentration indoors, exceeded the upper reference level in dwellings set at 300 Bq/m3 by the world health organization, in many scenarios. The mean value of the total excess lifetime cancer risk (due to external exposure from gamma-rays) was 2.29 × 10-3, above the world average value of 1.45 × 10-3. Furthermore, the measured radon concentrations in all water samples exceeded the EPA (Environmental Protection Agency) 11.1 Bq·L-1 standard for drinking water, ranging from 12 to 38 Bq·L-1 with a mean value of 27 Bq·L-1. The total annual effective dose (due to inhalation and ingestion) from radon in water, ranged from 58 to 192 μSv/y (for adults) exceeding the international permissible limit of 100 μSv/y, in seven out of eight samples. According to obtained results, the internal exposure from radon in directly used water from wells, might be the major reason of any suspected radiological health hazard especially in Haqal. The second reason might be the internal exposure from indoor radon gas inhalation in poorly ventilated dwellings.

A population level study on smoking and radon induced adenocarcinomaand small-cell carcinoma among males and females in Canada

Objective: To assess if there is a relationship between residential radon exposure and two lung cancer histologicaltypes, small-cell carcinoma (diagnosed in people with a smoking history) and adenocarcinoma (the mostcommonly diagnosed histologic type in people who have never smoked) among males and females in Canada.Methods: With survey data of long-term radon measurements in residential homes, long-term averaged tobaccoconsumption rates in the units of cigarettes per day per person and long-term averaged age-standardized lungcancer incidence rates at provincial level, simple linear fitting (ANOVA linear regression) was applied in this studyto determine the effect on lung cancer induction by smoking and exposure to indoor radon, and to assess if there isa relationship between residential radon exposure and lung cancer histological types.Results: Lung cancer incidence rates correlate very well with the tobacco consumption rates (P < 0.05). However,females appear to be more likely than males to develop lung cancer at a given amount of cigarette consumption.For both small-cell carcinoma and adenocarcinoma, a statistically significant correlation between incidence rateand mean radon concentration was observed for females, the correlation was much stronger for adenocarcinoma(P = 0.0057) than small-cell carcinoma (P = 0.0483). However, there was no such correlation for males.Conclusion: It is possible that female non-smokers are more susceptible to radon-induced lung cancer, and the jointeffect of radon exposure and tobacco smoking may be worse in female smokers compared to males, such thathigher incidence rate of adenocarcinoma among females compared to males were observed in recent decades,even though females never smoked more than males.