Ionizing radiation members, to comply with a European Directive. The FAA has a recommended limit of 1 mSv total for a pregnancy, and no more than 0.5 mSv per month. Information originally based on "Fundamentals of Aerospace Medicine" published in 2008. Hazardous levels of ionizing radiation are signified by the trefoil sign on a yellow background. These are usually posted at the boundary of a radiation controlled area or in any place where radiation levels are significantly above background due to human intervention. The red ionizing radiation warning symbol (ISO 21482) was launched in 2007, and is intended for IAEA Category 1,
Biological effects of radiation on the epigenome stimulus can cause beneficial adaptations in an organism. The ionizing radiation stimulates repair proteins that are usually not active. Cells use this new stimuli to adapt to the stressors they are being exposed to. In biology, the bystander effect is described as changes to nearby non-targeted cells in response to changes in an initially targeted cell by some disrupting agent. In the case of Radiation-Induced Bystander Effect, the stress on the cell is caused by ionizing radiation. The bystander effect can be broken down into two catagories, long range bystander effect and short range bystander effect. In long range bystander