Sleeping next to someone exposes you to about 0.05 microsieverts of radiation every night.

The human body is naturally radioactive because it contains small amounts of isotopes like Potassium-40 (K-40) and Carbon-14 (C-14). According to the Health Physics Society, an average adult contains about 140 grams of potassium, of which approximately 0.0117 percent is the radioactive isotope K-40. This isotope undergoes about 4,400 disintegrations per second, releasing beta particles and gamma rays within the body.When two people sleep side-by-side, they absorb a small portion of the gamma radiation emitted by their partner. Research into radiation safety often uses the 'Banana Equivalent Dose' (BED) to help the public understand low-level exposure. Eating one banana exposes a person to approximately 0.1 microsieverts of radiation due to its high potassium content. Therefore, sleeping next to someone for eight hours results in a dose of roughly 0.05 microsieverts, or half a banana.To put this in perspective, the average person in the United States receives about 6,200 microsieverts of radiation annually from all sources. This includes cosmic radiation from space, radon gas in the soil, and medical procedures like X-rays. A single chest X-ray delivers about 100 microsieverts, which is 2,000 times more than the dose received from a sleeping partner. Regulatory bodies like the Nuclear Regulatory Commission (NRC) confirm that these trace amounts of internal radiation are a natural part of biological existence and pose no health risk.