There were 444 workers at the site at the time of the accident. In Belarus alone 2.2 million people including 600,000 juveniles and children have been exposed to the prolonged impact of long-lived radionuclides. A total of 415 settlements have been evacuated, and the 130,000 residents resettled, making monitoring of them difficult. The actual death toll due to this catastrophe is hard to determine. Greenpeace Ukraine estimates the total number to be about 32,000.
Some estimates are higher, many are much lower.
The rate of thyroid cancer in children up to the age of 15 has increased 200 fold in Gomel Oblast, Belarus since the accident. Thyroid cancer is due to inhalation of radioactive iodine or ingestion from drinking milk from cows that have eaten grass that is contaminated with radioactive particles. When humans drink the milk, the iodine-134 becomes incorporated almost exclusively in the thyroid gland. Many diets in the fall-out affected area of the former Soviet Union are typically deficient in iodine. Individuals who had low levels of iodine in their diet incorporated large quantities of the radioactive iodine into their system as their bodies attempted to compensate for the deficiency.