ON THE SUBJECT OF SUBSTANTIATING COEFFICIENTS КМimAND КМdel CHARACTERIZING MODIFICATION OF THE ORGANISM RESPONSE TO RADIATION IMMEDIATELY OR IN DELAYED PERIODS DUE TO THE COMBINED ACTION OF THE STRESSFUL FACTORS IN EXTENDED ORBITAL AND EXPLORATION MISSIONS

Analysis of the huge array of experimental data on the effects of radiation and other physical and natural factors in space missions enabled substantiation of the coefficient of immediate response to radiation (КМim) in context of the risk to cosmonaut's health and efficiency. The КМim value lies with the range of 0.8 – 1.3. Currently, KMim can be taken equal to 1.0 owing to rapid cell recovery in the radiation sensitive bone marrow, GIT, lens epithelium, and brain cortex neurons during prolonged exposure to protons of the solar cosmic rays. The authors validate the modification coefficient for a delayed response (КМdel) presuming probable aggravating effects of air chemical contamination and weightlessness. The КМdel value was established using a calculated overall logarithmic index to quantify the level of stress to the body regulation systems, and functional reserve reduction. Acetone, acetaldehyde and ethanol vapors at maximal admissible concentrations may increase KMdel up to 1.5. Moreover, KMdel should be taken equal to 2.0 on the evidence that synergy of microgravity and GCR heavy nuclei threatens with morphological and functional CNS disorders, vascular damages and cardiovascular diseases and lifespan reduction.