Methods for Developing Spacecraft Water Exposure Guidelines -- Copyright -- OTHER REPORTS OF THE BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY -- OTHER REPORTS OF THE COMMITTEE ON TOXICOLOGY -- Preface -- Contents -- Abbreviations -- Executive Summary -- WATER CONTAMINANT SOURCES -- RANKING CONTAMINANTS FOR RISK ASSESSMENT -- DATA FOR ESTABLISHING SWEGS -- RISK ASSESSMENT -- SPECIAL CONSIDERATIONS FOR NASA -- EXPOSURE GUIDELINES SET BY OTHER ORGANIZATIONS -- 1 Introduction -- WATER CONTAMINANTS -- APPROACH TO THE STUDY -- REFERENCES -- 2 Sources, Treatment, and Monitoring Of Spacecraft Water Contaminants -- OVERVIEW -- DESIGN DRIVERS -- ISS WATER-QUALITY STANDARDS -- SOURCES OF SPACECRAFT WATER CONTAMINATION -- HUMAN URINE -- Untreated Urine -- Chemical Treatment and Distillation By-Products -- HUMIDITY CONDENSATE -- Condensate Sample Results -- Water Recovery Test -- Lunar-Mars Life Support Test Project -- Space Shuttle -- Mir Humidity Condensate -- Environmental Contributors to Spacecraft Humidity Condensate -- Hardware Off-Gassing -- Animal Wastes -- Mechanical Leaks -- Microbial Metabolites -- Payload Chemicals -- Utility Chemicals -- WASH WATER AND OTHER WASTE STREAMS -- Hygiene Water -- Detergents -- Chemicals from Personal Hygiene Products -- CHeCS Wastes -- CHEMICALS FORMED IN THE WATER TREATMENT SYSTEM -- SYSTEM FAILURES AND INCOMPLETE PROCESSING OF INFLUENT -- CHEMICALS ADDED TO RETARD BACTERIAL GROWTH -- Iodine -- Silver -- REGENERATED WATER -- Inorganic Contaminants -- Shuttle Humidity Condensates -- Mir Humidity Condensates and Mir Reclaimed Water -- LMLSTP 60-d Product Water -- ORGANIC CONTAMINANTS -- Humidity Condensate in Mir -- LMLSTP 60-d Product Water -- Stage-10 WRT -- MONITORING WATER CONTAMINANTS -- SOURCE-WATER MONITORING -- In-Line Monitoring and Process Control -- Off-Line Monitoring -- SUMMARY -- REFERENCES.

3 Sources and Types of Data for Establishing Spacecraft Water Exposure Guidelines -- CHEMICAL AND PHYSICAL CHARACTERISTICS OF A TOXICANT -- HUMAN STUDIES -- ANIMAL STUDIES -- IN VITRO TOXICITY STUDIES -- ADVANCES IN HEALTH EFFECTS ASSESSMENT -- NEUROBEHAVIORAL EFFECTS -- REPRODUCTIVE EFFECTS -- MUTAGENESIS -- MECHANISTIC STUDIES -- SUMMARY -- REFERENCES -- 4 Risk Assessment Methods for Determining Spacecraft Water Exposure Guidelines -- HISTORICAL PERSPECTIVE -- Risk Assessment for Noncarcinogenic Effects -- Risk Assessment for Carcinogenic Effects -- RECOMMENDED APPROACH TO RISK ASSESSMENT -- Exploiting Similarities of Historical Approaches -- Benchmark-Dose Approach to Setting SWEGs -- BMD CALCULATION -- Central Estimate Versus Confidence Limit -- Estimating BMDp for Various Toxic Effects -- EXPOSURE CONVERSION -- Target Tissue Dose -- Differences in Duration -- Species Conversions -- Different Routes -- UNCERTAINTY FACTORS -- Exposure Duration Uncertainty -- Interspecies Uncertainty -- Experimental Variation -- BMD10 to BMD01 -- Environmental Effects -- Other Factors -- SETTING SWEGS -- Overall Uncertainty Factor -- Mixtures of Chemicals -- Multiple Toxic End Points -- Comparisons with Established Values -- ALTERNATIVE APPROACHES -- Integrated PBPK and BBDR Models -- Ordinal Regression -- Change-Point Dose-Response Models -- SUMMARY -- REFERENCES -- 5 Ranking Spacecraft Contaminants For Risk Assessment -- APPROACHES TO RISK PRIORITIZATION -- AD HOC APPROACH -- AD HOC APPROACH WITH FACTORS SPECIFIED -- FORMAL SYSTEM WITH PARAMETERS, WEIGHTS, AND INTERRELATIONSHIPS SPECIFIED -- FLEXIBILITY OF RISK PRIORITIZATION -- SUMMARY -- REFERENCES -- Appendix A Water Reclamation Systems on Mir And the International Space Station -- MIRWATER-RECOVERY SYSTEMS -- HUMIDITY CONDENSATE PROCESSING -- FILTER-REACTOR CATALYTIC OXIDATION -- URINE PROCESSING.

U.S. WATER-PROCESSING SYSTEM -- URINE PROCESSING -- COMBINED URINE AND WASTEWATER PROCESSING -- MULTIFILTRATION SUBSYSTEM -- VOLATILE REMOVAL ASSEMBLY -- REQUIREMENTS, PROPOSED LIMITS, AND MONITORING -- REFERENCES -- Appendix B Benchmark Dose Estimation -- DERIVING BENCHMARK DOSES FOR 1,4-DICHLOROBENZENE -- NONQUANTAL RESPONSE DATA -- HIGHLY VARIABLE QUANTAL DATA -- CARCINOGENIC EFFECTS -- DISCUSSION -- DERIVING BMDS FOR BOTULINUM TOXIN, VINYL CHLORIDE, AND AFLATOXIN -- REFERENCES -- Appendix C Biographical Information on the Subcommittee on Spacecraft Water Exposure Guidelines.