Radiation doses
The highest doses were about 1000 people who were close to the reactor at the time of the explosion and took part in emergency work in the first few days after it. These doses ranged from 2 to 20 Gray (Gy), and in some cases were fatal.
Most of the liquidators who worked in a hazardous area in subsequent years, and local residents have received relatively small doses of radiation to the whole body. For liquidators they amounted to an average of 100 mSv, although sometimes exceeded 500. The doses received by residents evacuated from the heavily polluted areas, sometimes reaching several hundred millisievert, with an average value estimated at 33 mSv. The doses accumulated over the years after the accident, estimated at 10-50 mSv for the majority of residents of contaminated areas, and up to several hundred for some of them.
For comparison, the inhabitants of some regions of the Earth with high natural background (for example, in Brazil, India, Iran and China) are the radiation dose equal to about 100-200 mSv over 20 years.
Many local residents in the first weeks after the accident ate food (mainly milk), contaminated with radioactive iodine-131. Iodine accumulated in the thyroid gland, resulting in large doses to this organ, in addition to the whole body dose received by external radiation and the radiation of other radionuclides, lie inside the body. Residents of Pripyat, these doses were significantly reduced (estimated at 6 times) through the use of iodosoderzhaschih drugs. In other areas, such prophylaxis was not performed. These doses ranged from 0.03 to a few Gy, and in some cases reach 50 Gy.
Currently, most residents of the contaminated zone receives less than 1 mSv per year above natural background.