Abstract : Since the atomic bomb on Hiroshima, Japan the world pay attention on radiation and a lot of studies have been carried out and many research centers were established around the world to investigate the radiation consequences on living creatures, particularly on human. The goal of the current work is to inspect the outcome of the concentration of the dose and its range that causes many cancer types such as leukemia and solid cancer, at what range of the dose it will be fuzzy, and unknown. Most of previous studies shows that there are certain limits in which the radiation considered that has no biological effect on the human being (No risk), while the data that came from epidemiology investigation contains different related factors that has relation with diagnosis such as environmental exposure, genetic, style of life, accuracy of diagnosis and sociodemographics, etc.). There are interesting reports concerning the alert of low dose and its risk that come out due to exposure to medical radiation, that must be taking care of which eventually have another effect on the human health rather than cancer, particularly cataract risk, the cardiovascular and hear diseases, at doses under 1Sv. It was found that even at low risk dose of radiation, there are another biological effect of radiation on human health such as cataract and cardiovascular diseases.