If the cell is in interphase, while it is still a single strand of chromatin, the damage will be replicated during the S1 phase of cell cycle, and there will be a break on both chromosome arms; the damage then will be apparent in both daughter cells. If the irradiation occurs after replication, only one arm will bear the damage; this damage will be apparent in only one daughter cell. A damaged chromosome may cyclize, binding to another chromosome, or to itself. Diagnosis
Diagnosis is typically made based on a history of significant radiation exposure and suitable clinical findings. An absolute lymphocyte count can give a rough estimate of radiation exposure. Time from exposure to vomiting can also give estimates of exposure levels if they are less than 10 Gray (1000 rad). Prevention
A guiding principle of radiation safety is as low as reasonably achievable (ALARA). This means try to avoid exposure as much as possible and includes the three components of time, distance, and shielding. Time
The longer that humans are subjected to radiation the larger the dose will be. The advice in the nuclear war manual entitled Nuclear War Survival Skills published by Cresson Kearny in the U.S. was that if one needed to leave the shelter then this should be done as rapidly as possible to minimize exposure.In chapter 12, he states that "[q]uickly putting or dumping wastes outside is not hazardous once fallout is no longer being deposited.
Conventional trauma and burns resulting from a bomb blast are complicated by the poor wound healing caused by hematopoietic syndrome, increasing mortality. Gastrointestinal. This syndrome often follows absorbed doses of 6–30 grays (600–3,000 rad). The signs and symptoms of this form of radiation injury include nausea, vomiting, loss of appetite, and abdominal pain. Vomiting in this time-frame is a marker for whole body exposures that are in the fatal range above 4 grays (400 rad). Without exotic treatment such as bone marrow transplant, death with this dose is common, due generally more to infection than gastrointestinal dysfunction. Neurovascular. This syndrome typically occurs at absorbed doses greater than 30 grays (3,000 rad), though it may occur at doses as low as 10 grays (1,000 rad). It presents with neurological symptoms like dizziness, headache, or decreased level of consciousness, occurring within minutes to a few hours, with an absence of vomiting, and is almost always fatal, even with aggressive intensive care.Early symptoms of ARS typically include nausea, vomiting, headaches, fatigue, fever, and a short period of skin reddening. These symptoms may occur at radiation doses as low as 0.35 grays (35 rad). These symptoms are common to many illnesses, and may not, by themselves, indicate acute radiation sickness.