Detailed studies of the radiological consequences of the accident have been
conducted by the NRC, the Environmental Protection Agency, the Department
of Health, Education and Welfare (now Health and Human Services), the
Department of Energy, and the State of Pennsylvania. Several independent
studies have also been conducted. Estimates are that the average dose to about 2
million people in the area was only about 1 millirem. To put this into
context, exposure from a chest x‑ray is about 6 millirem. Compared to the
natural radioactive background dose of about 100‑125 millirem per year for the
area, the collective dose to the community from the accident was very
small. The maximum dose to a person at the site boundary would have been less
than 100 millirem.
In the months following the accident, although questions were raised about
possible adverse effects from radiation on human, animal, and plant life in
the TMI area, none could be directly correlated to the accident.
Thousands of environmental samples of air, water, milk, vegetation, soil, and
foodstuffs were collected by various groups monitoring the area. Very low
levels of radionuclides could be attributed to releases from the accident.
However, comprehensive investigations and assessments by several well‑respected
organizations have concluded that in spite of serious damage to the
reactor, most of the radiation was contained and that the actual release had
negligible effects on the physical health of individuals or the environment.
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