Space Toxicology: Toxicological Risk Management of Human Health during Space Exploration

Since the beginning of manned spaceflight, NASA has considered the overall health of astronaut crew members as vital for individual performance and wellbeing, as well as overall mission success. This was the impetus for the birth of space toxicology. Humans interacting with chemical constituents in enclosed or closed-loop environments are intrinsic to spaceflight; therefore these chemical exposures must be controlled and maintained at a level that is not detrimental to crew health. Despite engineering efforts, hundreds of chemicals will potentially be encountered in the closed-loop environment during spaceflight. Some chemicals that must be considered are those produced biologically by the crew members, as well as those originating from vehicular components, payload experiments and use of utility compounds. This chapter will ‘voyage’ to various facets of the discipline of space toxicology and its history, the unique astronaut population and spaceflight-induced physiological changes, air revitalization and water recovery, risk assessment and management, sources of chemical toxins and NASA's vision for future exploration. Keywords: space; space toxicology; space environment; closed-loop environment; astronauts; crew health; risk assessment; space toxicant; manned spaceflight; spacecraft; space habitat