At least three testers were evacuated to the Moscow Federal Medical Biophysical Center, where two subsequently died from their injuries. Later, ten workers from a regional hospital involved in treating the injured were themselves reportedly flown to the Moscow center.
A notice was issued to ships that they could not enter a 250-square kilometer area close to the accident. The Serebryanka—a nuclear fuel carrier likely modified to recover radioactive fragments from the ocean—remained in the area, having been present near the platform prior to the test.
Not unrelatedly, twenty miles to the west, the major Russian shipyard city of Severodvinsk reported a spike in gamma radiation twenty times the norm around noon. Technically, this remained within safe limits, and by 4 p.m., radiation levels began to normalize.
However, the radiation levels at Nyonoksa itself would surely have been of much higher—possibly releasing radionuclides into the atmosphere and drinking water that could increase cancer risk and cause other adverse health effects to those exposed.