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How does natural background radiation come from rocks and soil?

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The environmental effects of nuclear radiation — radiation The harmful effects of radiation from nuclear bombing.

Natural background radiation from rocks and soil originates primarily from the presence of radioactive elements within the Earth's crust. These terrestrial sources include uranium, thorium, and potassium-40, which have existed since the formation of the elements.1234

As these radioactive minerals undergo spontaneous decay, they release alpha particles, beta particles, and gamma rays. A significant component of this radiation is radon, a radioactive gas produced by the decay of radium (a decay product of uranium). Because radon is a gas, it can diffuse through soil and rock, potentially entering buildings through basements or foundations.2561

The concentration of these radioactive elements varies by geological formation, with higher levels often found in rocks like granite. This natural radioactivity is not only a source of background radiation for living organisms but also contributes to the internal heat of the Earth through the energy released during decay.6134