Radiation and Health:
Smoking and driving are much more dangerous then exposures to low levels of radiation.
Types of radiation:
The electromagnetic spectrum is divided into three segments with visible light in the middle.
The other two segments are referred to as ionizing and nonionizing, based on their biological
activity and span a wide range of wave lengths.
The ionizing portion of the spectrum includes gamma rays and ultraviolet radiation.
Ionizing radiation is given off by decaying radioisotopes or radionuclide, typically as beta
particles or gamma rays.
Ionizing radiation is genotoxic and can act as a carcinogens
Nonionizing radiation is not energetic enough to disrupt electrons and hence is not thought to
The radio-frequency range of the nonionizing-radation spectrum can heat tissues.
Melatonin hypothesis postulates a reduction in the pineal gland’s nocturnal production of
melatonin, which in turn could increase levels of estrogens and prolactin, reduce melatonin
inhibitory effect on cell proliferation and increase susceptibility to DNA damage through a
reduction in melatonin antioxidant action.
Health effects of ionizing Radiation:
What we know about radiation health effects comes principally from three sources: 1) long-term
follow up of the survivors of the atomic bombings in Hiroshima and Nagasaki, which involved an
acute exposure to high radiation close at high dose rates. 2) Studies of patients receiving
diagnostic and therapeutic radiation