 Later analyses concluded that, even with very conservative estimates, relocation of the city (or of any area below 1500 kBq/m2) could not be justified on the grounds of radiological health.This however does not account for the uncertainty in the first few days of the accident about further depositions and weather patterns.Moreover, an earlier short-term evacuation could have averted more significant doses from short-lived isotope radiation (specifically iodine-131, which has a half-life of about eight days).