Epidemiological investigation of radiological effects in high background radiation areas of Yangjiang, China.

The risk estimates of exposure to ionizing radiation in human populations are based largely on information from intermediate and high doses and dose rates, whereas radiological protection is usually concerned with low does and low dose rated, specifically with evaluation of health risk associated with does less than 0.05 Sv per year, received at low dose rates. Many studies have shoen that the effects of low LET radiation of low dose exposure will be less detrimental than expected from a linear extrapolation of fingings at moderate to high doses and high dose rates. However, how much less is debatable. The reason of debates is: opportunities to collect information pertinent to the exposure of a general population to low doses at low dose rated are scanty.