Methods for Developing Spacecraft Water Exposure Guidelines

0309071348......Page 1
Copyright......Page 3
OTHER REPORTS OF THE BOARD ON ENVIRONMENTAL STUDIES AND TOXICOLOGY......Page 10
OTHER REPORTS OF THE COMMITTEE ON TOXICOLOGY......Page 12
Preface......Page 14
Contents......Page 18
Abbreviations......Page 20
Executive Summary......Page 24
WATER CONTAMINANT SOURCES......Page 25
RANKING CONTAMINANTS FOR RISK ASSESSMENT......Page 26
DATA FOR ESTABLISHING SWEGS......Page 27
RISK ASSESSMENT......Page 28
SPECIAL CONSIDERATIONS FOR NASA......Page 29
EXPOSURE GUIDELINES SET BY OTHER ORGANIZATIONS......Page 30
1 Introduction......Page 32
WATER CONTAMINANTS......Page 33
REFERENCES......Page 35
OVERVIEW......Page 37
DESIGN DRIVERS......Page 38
ISS WATER-QUALITY STANDARDS......Page 39
SOURCES OF SPACECRAFT WATER CONTAMINATION......Page 41
Untreated Urine......Page 43
Chemical Treatment and Distillation By-Products......Page 44
HUMIDITY CONDENSATE......Page 45
Water Recovery Test......Page 46
Space Shuttle......Page 47
Mir Humidity Condensate......Page 51
Animal Wastes......Page 53
Mechanical Leaks......Page 54
Microbial Metabolites......Page 55
Detergents......Page 56
CHeCS Wastes......Page 57
SYSTEM FAILURES AND INCOMPLETE PROCESSING OF INFLUENT......Page 58
Iodine......Page 59
Inorganic Contaminants......Page 60
Shuttle Humidity Condensates......Page 61
Mir Humidity Condensates and Mir Reclaimed Water......Page 62
LMLSTP 60-d Product Water......Page 64
LMLSTP 60-d Product Water......Page 65
Stage-10 WRT......Page 68
SOURCE-WATER MONITORING......Page 71
Off-Line Monitoring......Page 72
SUMMARY......Page 74
REFERENCES......Page 76
3 Sources and Types of Data for Establishing Spacecraft Water Exposure Guidelines......Page 80
CHEMICAL AND PHYSICAL CHARACTERISTICS OF A TOXICANT......Page 81
HUMAN STUDIES......Page 82
ANIMAL STUDIES......Page 83
ADVANCES IN HEALTH EFFECTS ASSESSMENT......Page 86
NEUROBEHAVIORAL EFFECTS......Page 87
REPRODUCTIVE EFFECTS......Page 89
MUTAGENESIS......Page 90
MECHANISTIC STUDIES......Page 92
SUMMARY......Page 93
REFERENCES......Page 94
4 Risk Assessment Methods for Determining Spacecraft Water Exposure Guidelines......Page 98
Risk Assessment for Noncarcinogenic Effects......Page 99
Risk Assessment for Carcinogenic Effects......Page 100
Exploiting Similarities of Historical Approaches......Page 102
Benchmark-Dose Approach to Setting SWEGs......Page 103
Central Estimate Versus Confidence Limit......Page 105
Estimating BMDp for Various Toxic Effects......Page 106
Differences in Duration......Page 107
Species Conversions......Page 109
Exposure Duration Uncertainty......Page 110
Experimental Variation......Page 111
Environmental Effects......Page 113
Other Factors......Page 115
Overall Uncertainty Factor......Page 116
Multiple Toxic End Points......Page 119
ALTERNATIVE APPROACHES......Page 120
Integrated PBPK and BBDR Models......Page 121
Ordinal Regression......Page 122
SUMMARY......Page 123
REFERENCES......Page 124
5 Ranking Spacecraft Contaminants For Risk Assessment......Page 131
AD HOC APPROACH WITH FACTORS SPECIFIED......Page 132
FORMAL SYSTEM WITH PARAMETERS, WEIGHTS, AND INTERRELATIONSHIPS SPECIFIED......Page 133
SUMMARY......Page 135
REFERENCES......Page 136
MIRWATER-RECOVERY SYSTEMS......Page 138
HUMIDITY CONDENSATE PROCESSING......Page 139
URINE PROCESSING......Page 141
URINE PROCESSING......Page 142
COMBINED URINE AND WASTEWATER PROCESSING......Page 144
MULTIFILTRATION SUBSYSTEM......Page 145
REQUIREMENTS, PROPOSED LIMITS, AND MONITORING......Page 146
REFERENCES......Page 153
DERIVING BENCHMARK DOSES FOR 1,4-DICHLOROBENZENE......Page 154
NONQUANTAL RESPONSE DATA......Page 157
HIGHLY VARIABLE QUANTAL DATA......Page 159
CARCINOGENIC EFFECTS......Page 162
DISCUSSION......Page 163
DERIVING BMDS FOR BOTULINUM TOXIN, VINYL CHLORIDE, AND AFLATOXIN......Page 165
REFERENCES......Page 171
Appendix C Biographical Information on the Subcommittee on Spacecraft Water Exposure Guidelines......Page 172