Frequent Questions

Why do I see higher levels of radiation at some monitor locations?

The normal background radiation levels in one location may be different from the normal background radiation levels in another. The normal background level of radiation at any one location depends on factors including:

  • Altitude (monitoring data from higher altitude locations may show a higher level of normal background radiation because of a greater contribution from cosmic radiation).
  • The amount of naturally-occurring radioactive materials in the soil and air.
  • Weather conditions (for example, rainfall, snowfall and changes in atmospheric pressure) may account for variations in measured background radiation levels; some such conditions can cause increases, and others may cause decreases in measured radiation levels.

For more information about background radiation, visit Radiation Sources and Doses on EPA.gov.

For more information about RadNet, visit RadNet on EPA.gov.

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