 Complete the following phrase:  Chronic radiation syndrome CRS, or chronic radiation enteritis, is a constellation of health effects of radiation that occur after months or years of chronic exposure to high amounts of radiation. Chronic radiation syndrome develops with a speed and severity proportional to the radiation dose received i.e., it is a deterministic effect of exposure to ionizing radiation, unlike radiation-induced cancer. It is distinct from acute radiation syndrome, in that it occurs at dose rates low enough to permit natural repair mechanisms to compete with the radiation damage during the exposure period. Dose rates high enough to cause the acute form  0.1 Gyh are fatal long before onset of the chronic form. The lower threshold for chronic radiation syndrome is between 0.7 and 1.5 Gy, at dose rates above 0.1 Gyyr. This condition is primarily known from the 