Mild Symptoms Because the cells that line the intestines are very susceptible to damage from radiation, the first symptoms to appear in most cases of radiation poisoning are nausea and vomiting. The amount of time from the exposure to the onset of vomiting is a direct indicator to how much radiation the patient absorbed.
Mild radiation sickness occurs in those who have been exposed to 1 Gy to 2 Gy of radiation. The onset of nausea and vomiting in this case is usually between 24 to 48 hours, according to doctors at the Mayo Clinic. Other symptoms may occur, including headache, fatigue and general weakness. These symptoms may not appear for several days after the initial nausea and vomiting.
Read more: http://www.livestrong.com/article/74118-effects-radiation-poisoning/#ixzz1FDhSaAeW