ASSOCIATION BETWEEN LOCAL EXTERNAL GAMMA RAYS AND FREQUENCY OF CANCER IN BABOL-IRAN

摘要

Introduction: The effect of natural background radiation on Cancer is still challenging. The investigation of association between external gamma rays and Cancer was the main goal of study. Materials & Methods: External Gamma rays were measured using a radiation survey meter in 184 urban and rural health centers to estimate the exposure to the population in residential areas of Babol. The dose distribution map was compared to the 5 years radiation induced cancer incidence data from cancer registry center in north part of Iran. Results: Results showed that although the external gamma ray level in Babol is nearly equal to the average natural background radiation in the world, there is a relatively weak inverse association between local external gamma ray and incidence of Cancer [Correlation coefficient = –0.43, (p<0.01)]. Conclusion: This finding might be due to the inhibition of cancer induction following exposure to the low doses of ionizing radiation and probably can be a confirmation of radiation hormesis. However, due to some uncertainties, the conclusion should be interpreted with caution. Further national and international studies are suggested.