Guidelines from the International Radiation Protection Association (IRPA) suggest overall radiation limits of 1 milliwatt per square centimeter «averaged over 6 minutes (0.1 h) period.» (wellnessmama.com)
Wheat ears from these plants contained 300 - 500 Bq kg - 1 — within the prescribed radiation limit. (scientificamerican.com)
Measurements of radiation reaching the shielded interior of the spacecraft that carried Curiosity to Mars indicate that an astronaut on a yearlong round - trip would be exposed to around two - thirds of the career radiation limit that some space agencies set. (sciencenews.org)