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Technological Hazard >> Radiation hazard >>Health effects of radiation
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Nature of radioactivity, types of radiation Interaction radiation with matter Radiation sources, natural and artificial radiation |
Ionizing
radiation affects people by depositing energy in body tissue, which can cause
cell damage or cell death. In some cases there may be no effect. In other
cases, the cell may survive but become abnormal, either temporarily or
permanently, or an abnormal cell may become malignant. Large doses of
radiation can cause extensive cellular damage and result in death. With
smaller doses, the person or particular irradiated organ(s) may survive, but
the cells are damaged, increasing the chance of cancer. The extent of the
damage depends upon the total amount of energy absorbed, the time period and
dose rate of exposure, and the particular organ(s) exposed. Evidence of injury from low or moderate doses of radiation may not show up for months or even years. For leukemia, the minimum time period between the radiation exposure and the appearance of disease (latency period) is 2 years. For solid tumors, the latency period is more than 5 years. The types of effects and their probability of occurrence can depend on whether the exposure occurs over a large part of a person's lifespan (chronic) or during a very short portion of the lifespan (acute).
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