title: Radiation effects in space.
abstract: The radiation protection guidelines of the National Aeronautics and Space Administration (NASA) are under review by Scientific Committee 75 of the National Council Protection and Measurements. The re-evaluation of the current guidelines is necessary, first, because of the increase in information about radiation risks since 1970 when the original recommendations were made and second, the population at risk has changed. For example, women have joined the ranks of the astronauts. Two types of radiation, protons and heavy ions, are of particular concern in space. Unfortunately, there is less information about the effects on tissues and cancer by these radiations than by other radiations. The choice of Quality Factors (Q) for obtaining dose equivalents for these radiations, is an important aspect of the risk estimate for space travel. There are not sufficient data for the induction of late effects by either protons or by heavy ions. The current information suggests a RBE for the relative protons of about 1, whereas, a RBE of 20 for tumor induction by heavy ions, such as iron-56, appears appropriate. The recommendations for the dose equivalent career limits for skin and the lens of the eye have been reduced but the 30-day and annual limits have been raised.
authors.affiliation: Biology Division, Oak Ridge National Laboratory, TN 37831, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Fry
mesh_terms: D000818:Animals; D018480:Astronauts; D005260:Female; D006243:Harderian Gland / Q000166:cytology / Q000528:radiation effects; D020450:Heavy Ions; D006801:Humans; D007908:Lens, Crystalline / Q000528:radiation effects; D018499:Linear Energy Transfer; D008297:Male; D009381:Neoplasms, Radiation-Induced; D011522:Protons; D011835:Radiation Protection / Q000592:standards*; D012062:Relative Biological Effectiveness; D012867:Skin / Q000166:cytology / Q000528:radiation effects; D013026:Space Flight; D013737:Testis / Q000528:radiation effects
chemical_list: D011522:Protons