How do you set exposure limits to protect human health in a closed container floating in space? Valerie Ryder, a toxicologist at the NASA Johnson Space Center, takes co-hosts Anne Chappelle and David Faulkner into the small world of space toxicologists, where they also discuss research involving lunar dust, bone loss, and CO2.About the GuestValerie Ryder, PhD, DABT, is a board-certified toxicologist with the NASA Johnson Space Center. She received a BA in chemistry with a minor in microbiology from Texas A&M University in 2000 and a PhD in pathology from the University of Alabama at Birmingham in 2004.  As an undergraduate, Dr. Ryder worked in the oceanography department in the laboratory of Dr. Luis Cifuentes. As a graduate student, she supported the dynamically controlled protein crystal growth shuttle flight experiment on STS-105 and studied altered differentiation of adult stem cells in modeled microgravity under the NASA Graduate Student Researcher Program. After completing her graduate work, Dr. Ryder worked briefly as a scientific writer before joining the toxicology group at the Texas Commission on Environmental Quality in 2005. In 2008, she accepted a position as a toxicologist with Wyle’s Integrated Science and Engineering Group. In 2010, Dr. Ryder became a NASA Civil Servant and took over as the lead for the toxicology group in 2014. She leads a team of toxicologists who work to ensure that the air and water onboard spacecraft are safe for crew health. DisclaimerThe viewpoints and information presented in Adverse Reactions represent those of the participating individuals. Although the Society of Toxicology holds the copyright to the production, it does not vet or review the information presented, nor does presenting and distributing the Adverse Reactions podcast represent any proposal or endorsement of any position by the Society.