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All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Inferring microbial interactions with their environment from genomic and metagenomic data

Microbial communities assemble through a complex set of interactions between microbes and their environment, and the resulting metabolic impact on the host ecosystem can be profound. Microbial activity is known to impact human health, plant growth, water quality, and soil carbon storage which has lead to the development of many approaches and products meant to manipulate the microbiome. In order to understand, predict, and improve microbial community engineering, genome-scale modeling techniques have been developed to translate genomic data into inferred microbial dynamics. However, these techniques rely heavily on simulation to draw conclusions which may vary with unknown parameters or initial conditions, rather than more robust qualitative analysis. To better understand microbial community dynamics using genome-scale modeling, we provide a tool to investigate the network of interactions between microbes and environmental metabolites over time. Using our previously developed algorithm for simulating microbial communities from genome-scale metabolic models (GSMs), we infer the set of microbe-metabolite interactions within a microbial community in a particular environment. Because these interactions depend on the available environmental metabolites, we refer to the networks that we infer as metabolically contextualized , and so name our tool MetConSIN: Met abolically Con textualized S pecies I nteraction N etworks.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2025

bmdrc: Python package for quantifying phenotypes from chemical exposures with benchmark dose modeling

Though chemical exposures are known to potentially have negative impacts on health, including contributing to chronic diseases such as cancer, the quantitative contribution of risk is not fully understood for every chemical. A commonly used approach to quantify levels of risk is to measure the proportion of organisms (such as a total number of zebrafish on a plate or mice in a cage) with abnormal behavioral responses or morphology at increasing concentrations of chemical exposure. A particular challenge with processing the proportional data from these assays is the appropriate estimation of chemical concentration levels that result in malformations or acute toxicity, as these values typically vary between experimental measurements. The recommended approach by the Environmental Protection Agency (EPA) is to fit benchmark dose curves with specific filters and model fitting steps, which are crucial to properly processing the proportional data. Several tools exist for the fitting of benchmark dose response curves, but none are standalone Python libraries built to process both morphological and behavioral data as proportions with all the EPA recommended filters, filter parameters, models, and model parameters. Thus, here we present the benchmark dose response curve (bmdrc) Python library, which was built to closely follow these EPA guidelines with helpful visualizations of filters and fitted model curves, and reports for reproducibility purposes. bmdrc is open-source and has demonstrated utility as a support package to an existing web portal for information on chemicals (https://srp.pnnl.gov). Our package will support any toxicology analysis where the response is a proportional value at increasing levels of a concentration of a chemical or chemical mixture.

Superfund↗
DOE OSTI2023

Assessment of Potential Dose and Environmental Impacts from Proposed Testing at the INL Radiological Response Training Range

This assessment uses screening-level models to calculate potential environmental impacts from proposed tests at the Idaho National Laboratory (INL) Radiological Response Training Range (RRTR) site. Proposed tests could be conducted using 11 different radioactive material types that include K2O, LaBr3, KBr, Cu, Zr, F, Ga, Ga2O3, NaNO2, Ga-68, and Tc-99m. The tests could potentially release radioactive material to the atmosphere and radionuclides and other contaminants to the soil, which could leach into the unsaturated zone and migrate to the aquifer. Atmospheric transport of radionuclides to potential human receptors and time-integrated air concentrations were calculated with a Gaussian plume model and three years of hourly meteorological data. Potential surface-soil impacts were calculated with the computer program mixing-cell model (MCM). Groundwater impacts were calculated with the computer programs MCM and GWSCREEN. Radiological doses from potential atmospheric releases were calculated for public receptors off the INL Site and for workers at nearby INL facilities. Results were compared to regulatory dose limits. Maximum potential groundwater concentrations were estimated in the aquifer below the NSTR site and compared to drinking water standards or risk-based screening levels for resident tap water. Soil concentrations were calculated and compared to risk-based screening levels for workers and potential future residents. All impacts were estimated assuming 12 tests are conducted annually using all 11 material types for a period of 15 years. This document provides the resources to enable a subject matter expert in the field of environmental assessments to replicate the modeling and calculations. The methodology and parameters are presented in the text. All electronic files, including computer-code input, output, executable files, batch files, scripts, and spreadsheet files are contained in a zip file that can be accessed by selecting “Additional Information” (select Native File) in the INL Electronic Document Management System (EDMS). It is highly unlikely the test scenarios evaluated in this ECAR will adversely impact human health based on comparisons of calculated dose and concentration against regulatory standards and risk-based screening levels. Conservative estimates of dose to workers and the public from atmospheric transport of possible radionuclide releases are far below federal radiation protection standards. Conservative estimates of potential contaminant concentrations in groundwater are less than federal drinking water standards or screening levels. Predicted radionuclide concentrations in surface soils are below risk-based screening levels, except for Ge-68 (material Ga-68) for the worker. The Ge-68 soil concentration can be made less than the worker PRG, if the number of annual tests using Ga-68 is reduced from 12 to 6. However, the sum of ratios still exceeds one because of the high K-40 ratio. If the EF of the worker (number of days the worker is in the contaminated testing area) is reduced from 225 days/yr (default value for full time worker) to 112 days/yr, the Ge-68 ratio is less than one and the sum of ratios is less than one. Actual radiation doses and groundwater and surface-soil concentrations are likely to be much less than those calculated because of the conservative assumptions and parameters employed in the modeling. For example, atmospheric-transport calculations assume the entire inventory of each material type is readily released to the atmosphere and no plume deposition, depletion, or radioactive decay occurs during transport. The calculations also assume the same meteorological conditions (e.g., wind velocity, wind direction, stability class) that produce the maximum 95th percentile concentration (i.e., concentration representing the 95th percentile of a distribution of concentrations derived from 3 years of hourly meteorological data) at each receptor location are the same for all 12 tests during the year, and each receptor is assumed to be present during all 12 tests. The surface-soil assessment assumes the entire inventory of each test is deposited in the top 5 cm of soil. No atmospheric dispersal is assumed, and the radionuclides are subject only to leaching and radioactive decay. The groundwater-pathway modeling is conservative in that it is one-dimensional in the unsaturated zone (no lateral spreading/dilution) and assumes the entire inventory of contaminants infiltrates into the ground at the same location for every test. This is especially conservative for particulate radionuclides because they would have to dissolve or corrode first and some would be dispersed into the atmosphere. The groundwater receptor is also assumed to consume water directly from a hypothetical well positioned in the location of maximum concentration. In addition, conservative degradation rates were used, and volatilization was not considered for the nonradioactive chemical

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Assessment of Potential Dose and Environmental Impacts from Proposed Testing at the INL National Security Test Range

This assessment uses screening-level models to calculate potential environmental impacts from proposed tests at two locations at the Idaho National Laboratory (INL) National Security Test Range (NSTR) site. Proposed tests could be conducted using 11 different radioactive material types that include K 2 O, LaBr 3 , KBr, Cu, Zr, F, Ga, Ga 2 O 3 , NaNO 2 , Ga-68, and Tc-99m. The tests could potentially release radioactive material to the atmosphere and radionuclides and other contaminants to the soil, which could leach into the unsaturated zone and migrate to the aquifer. Atmospheric transport of radionuclides to potential human receptors and time-integrated air concentrations were calculated with a Gaussian plume model and three years of hourly meteorological data. Potential surface-soil impacts were calculated with the computer program mixing-cell model (MCM). Groundwater impacts were calculated with the computer programs MCM and GWSCREEN. Radiological doses from potential atmospheric releases were calculated for public receptors off the INL Site and for workers at nearby INL facilities. Results were compared to regulatory dose limits. Maximum potential groundwater concentrations were estimated in the aquifer below the NSTR site and compared to drinking water standards or risk-based screening levels for resident tap water. Soil concentrations were calculated and compared to risk-based screening levels for workers and potential future residents. All impacts were estimated based on the assumption that 12 tests are conducted annually using all 11 material types for 15 years. This document provides the resources to enable a subject matter expert in the field of environmental assessments to replicate the modeling and calculations. The methodology and parameters are presented in the text. All electronic files, including computer-code input, output, executable files, batch files, scripts, and spreadsheet files, are contained in a zip file that can be accessed by selecting “Additional Information” (select Native File) in the INL Electronic Document Management System (EDMS). It is highly unlikely the test scenarios evaluated in this ECAR will adversely impact human health based on comparisons of calculated dose and concentration against regulatory standards and risk-based screening levels. Conservative estimates of dose to workers and the public from atmospheric transport of possible radionuclide releases are far below federal radiation protection standards. Conservative estimates of potential contaminant concentrations in groundwater are less than federal drinking water standards or screening levels. Predicted radionuclide concentrations in surface soils are below risk-based screening levels, except for Ge-68 (material Ga-68) for the worker. The Ge-68 soil concentration can be made less than the worker PRG, if the number of annual tests using Ga-68 is reduced from 12 to 6. However, the sum of ratios still exceeds one because of the high K-40 ratio. If the EF of the worker (number of days the worker is in the contaminated testing area) is reduced from 225 days/yr (default value for full time worker) to 112 days/yr, the Ge-68 ratio is less than one and the sum of ratios is less than one. Actual radiation doses and groundwater and surface-soil concentrations are likely to be much less than those calculated because of the conservative assumptions and parameters employed in the modeling. For example, atmospheric-transport calculations assume the entire inventory of each material type is readily released to the atmosphere and no plume deposition, depletion, or radioactive decay occurs during transport. The calculations also assume the same meteorological conditions (e.g., wind velocity, wind direction, stability class) that produce the maximum 95th percentile concentration (i.e., concentration representing the 95th percentile of a distribution of concentrations derived from 3 years of hourly meteorological data) at each receptor location are the same for all 12 tests during the year, and each receptor is assumed to be present during all 12 tests. The surface-soil assessment assumes the entire inventory of each test is deposited in the top 5 cm of soil. No atmospheric dispersal is assumed, and the radionuclides are subject only to leaching and radioactive decay. The groundwater-pathway modeling is conservative in that it is one-dimensional in the unsaturated zone (no lateral spreading/dilution) and assumes the entire inventory of contaminants infiltrates into the ground at the same location for every test. This is especially conservative for particulate radionuclides because they would have to dissolve or corrode first and some would be dispersed into the atmosphere. The groundwater receptor is also assumed to consume water directly from a hypothetical well positioned in the location of maximum concentration. In addition, conservative degradation rates were used, and volatilization was not considered for the nonradradioactive chemicals modeled. And finally, the calculations assume all 12 tests will be performed at the same place at both locations, and all 11 radioactive material types will be used for each test. This is conservative because it is anticipated that no more than two material types will be used per test.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2023

Collaborating with Utilities to Meet Underserved Community Needs: A Guide to Equitable Commercial Solar and Solar + Storage Deployment

Communities of color and low-income populations dedicate a disproportionate amount of their income to pay for energy. They also experience more frequent and prolonged service disruptions, impacting community health and safety. When designed correctly, commercial solar + storage installations have the potential to ameliorate these issues. However, utility programs created to support such installations are frequently underutilized because communities often lack the time and resources needed to access them. Further, historically, few utilities have had the motivation and incentives or experience to account for this barrier. RMI provided process support to Solar Energy Innovation Network teams, and described their experiences in accessing these clean energy resources to support historically underserved communities in our latest report. The report also outlines the roles of key stakeholders (e.g., utilities, building owners, and community organizations) in supporting program delivery and recommended practices to collaborate to meet community needs. The report focuses on commercial solar and solar + storage resources, including solar + storage microgrids. These technologies can offer benefits to communities who do not own their own properties. When designed to act as a "resilience hub," they can also support communities in times of electricity disruption. The report includes a step-by-step guide to collaborating with utilities to implement programs for historically underserved customers. Utilities can support these projects with financing assistance, modernized rate designs, and, in the deployment phase, technical assistance for system design and interconnection.

14 SOLAR ENERGY↗
DOE OSTI2026

JUMP Into STEM 2018-2025: Challenge Highlights and Implementation Guidance

Building sciences and technology directly impact human health, productivity, and resource consumption (e.g., energy and critical minerals). Addressing emerging challenges in this field requires skilled building science professionals. JUMP into STEM sought to inspire the next generation of building scientists through a real-world competition that introduced participants to the field and connected them with national laboratory and industry professionals. This report highlights select challenges from past competitions which are tailored for academic and industry professionals who aim to develop or recruit multidisciplinary talent. It also includes additional guidance to support the effective replication of these challenges.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2024

Effect of Environmental and Socioeconomic Factors on Increased Early Childhood Blood Lead Levels: A Case Study in Chicago

This study analyzes the prevalence of elevated blood lead levels (BLLs) in children across Chicagoland zip codes from 2019 to 2021, linking them to socioeconomic, environmental, and racial factors. Wilcoxon tests and generalized additive model (GAM) regressions identified economic hardship, reflected in per capita income and unemployment rates, as a significant contributor to increased lead poisoning (LP) rates. Additionally, LP rates correlate with the average age of buildings, particularly post the 1978 lead paint ban, illustrating policy impacts on health outcomes. The study further explores the novel area of land surface temperature (LST) effects on LP, finding that higher nighttime LST, indicative of urban heat island effects, correlates with increased LP. This finding gains additional significance in the context of anthropogenic climate change. When these factors are combined with the ongoing expansion of urban territories, a significant risk exists of escalating LP rates on a global scale. Racial disparity analysis revealed that Black and Hispanic/Latino populations face higher LP rates, primarily due to unemployment and older housing. The study underscores the necessity for targeted public health strategies to address these disparities, emphasizing the need for interventions that cater to the unique challenges of these at-risk communities.

Lee, Jangho (ORCID:0000000289421092)↗
DOE OSTI2021

Effects of Low Dose Space Radiation Exposures on the Splenic Metabolome

Future space missions will include a return to the Moon and long duration deep space roundtrip missions to Mars. Leaving the protection that Low Earth Orbit provides will unavoidably expose astronauts to higher cumulative doses of space radiation, in addition to other stressors, e.g., microgravity. Immune regulation is known to be impacted by both radiation and spaceflight and it remains to be seen whether prolonged effects that will be encountered in deep space can have an adverse impact on health. In this study, we investigated the effects in the overall metabolism of three different low dose radiation exposures (γ-rays, 16O, and 56Fe) in spleens from male C57BL/6 mice at 1, 2, and 4 months after exposure. Forty metabolites were identified with significant enrichment in purine metabolism, tricarboxylic acid cycle, fatty acids, acylcarnitines, and amino acids. Early perturbations were more prominent in the γ irradiated samples, while later responses shifted towards more prominent responses in groups with high energy particle irradiations. Regression analysis showed a positive correlation of the abundance of identified fatty acids with time and a negative association with γ-rays, while the degradation pathway of purines was positively associated with time. Taken together, there is a strong suggestion of mitochondrial implication and the possibility of long-term effects on DNA repair and nucleotide pools following radiation exposure.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Distinct Conformations of SARS-CoV-2 Omicron Spike Protein and Its Interaction with ACE2 and Antibody

Since November 2021, Omicron has been the dominant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant that causes the coronavirus disease 2019 (COVID-19) and has continuously impacted human health. Omicron sublineages are still increasing and cause increased transmission and infection rates. The additional 15 mutations on the receptor binding domain (RBD) of Omicron spike proteins change the protein conformation, enabling the Omicron variant to evade neutralizing antibodies. For this reason, many efforts have been made to design new antigenic variants to induce effective antibodies in SARS-CoV-2 vaccine development. However, understanding the different states of Omicron spike proteins with and without external molecules has not yet been addressed. In this review, we analyze the structures of the spike protein in the presence and absence of angiotensin-converting enzyme 2 (ACE2) and antibodies. Compared to previously determined structures for the wildtype spike protein and other variants such as alpha, beta, delta, and gamma, the Omicron spike protein adopts a partially open form. The open-form spike protein with one RBD up is dominant, followed by the open-form spike protein with two RBD up, and the closed-form spike protein with the RBD down. It is suggested that the competition between antibodies and ACE2 induces interactions between adjacent RBDs of the spike protein, which lead to a partially open form of the Omicron spike protein. The comprehensive structural information of Omicron spike proteins could be helpful for the efficient design of vaccines against the Omicron variant.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Loss of Mitochondrial Tusc2/Fus1 Triggers a Brain Pro-Inflammatory Microenvironment and Early Spatial Memory Impairment

Brain pathological changes impair cognition early in disease etiology. There is an urgent need to understand aging-linked mechanisms of early memory loss to develop therapeutic strategies and prevent the development of cognitive impairment. Tusc2 is a mitochondrial-resident protein regulating Ca 2+ fluxes to and from mitochondria impacting overall health. We previously reported that Tusc2 –/– female mice develop chronic inflammation and age prematurely, causing age- and sex-dependent spatial memory deficits at 5 months old. Therefore, we investigated Tusc2-dependent mechanisms of memory impairment in 4-month-old mice, comparing changes in resident and brain-infiltrating immune cells. Interestingly, Tusc2 –/– female mice demonstrated a pro-inflammatory increase in astrocytes, expression of IFN-γ in CD4 + T cells and Granzyme-B in CD8 + T cells. We also found fewer FOXP3 + T-regulatory cells and Ly49G + NK and Ly49G + NKT cells in female Tusc2 –/– brains, suggesting a dampened anti-inflammatory response. Moreover, Tusc2 –/– hippocampi exhibited Tusc2- and sex-specific protein changes associated with brain plasticity, including mTOR activation, and Calbindin and CamKII dysregulation affecting intracellular Ca2 + dynamics. Overall, the data suggest that dysregulation of Ca 2+ -dependent processes and a heightened pro-inflammatory brain microenvironment in Tusc2 –/– mice could underlie cognitive impairment. Thus, strategies to modulate the mitochondrial Tusc2- and Ca 2+ - signaling pathways in the brain should be explored to improve cognitive health.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1981

Report of activities of the advanced coal extraction systems definition project, 1979 - 1980

During this period effort was devoted to: formulation of system performance goals in the areas of production cost, miner safety, miner health, environmental impact, and coal conservation, survey and in depth assessment of promising technology, and characterization of potential resource targets. Primary system performance goals are to achieve a return on incremental investment of 150% of the value required for a low risk capital improvement project and to reduce deaths and disability injuries per million man-hour by 50%. Although these performance goals were developed to be immediately applicable to the Central Appalachian coal resources, they were also designed to be readily adaptable to other coals by appending a geological description of the new resource. The work done on technology assessment was concerned with the performance of the slurry haulage system.

Lavin, M. L.↗
NASA NTRS1981

Requirements for the conceptual design of advanced underground coal extraction systems

Conceptual design requirements are presented for underground coal mining systems having substantially improved performance in the areas of production cost and miner safety. Mandatory performance levels are also set for miner health, environmental impact, and coal recovery. In addition to mandatory design goals and constraints, a number of desirable system characteristics are identified which must be assessed in terms of their impact on production cost and their compatibility with other system elements. Although developed for the flat lying, moderately thick seams of Central Appalachia, these requirements are designed to be easily adaptable to other coals.

Gangal, M. D.↗
NASA NTRS1999

The Influence of Passive Acceleration and Exercise+Acceleration on Work Capacity and Orthostasis

The losses of aerobic power and orthostatic tolerance are significant effects of manned C) spaceflight that can negatively impact crew health and safety. Daily acceleration and aerobic training may ameliorate these effects. To determine the influence of passive intermittent +Gz acceleration (PA) training and active acceleration + interval exercise (AE) training on work 0 0 capacity and the acute (1 min) response to 70 deg head-up tilt, 6 men (X-Bar SD: age, 33 +/- 6 y; height, 178.3 +/- 4.6 cm; mass, 86.3 +/- 6.6 kg) participated in two 3-wk training protocols. It was hypothesized that PA and AE training would improve orthostatic tolerance and that the addition of aerobic conditioning, would not alter this effect.

Simonson, S. R.↗
NASA NTRS2001

Satellite Observations of Tropospheric Chemistry

The troposphere is an essential component of the earth's life support system as well as the gateway for the exchange of chemicals between different geochemical reservoirs of the earth. The chemistry of the troposphere is sensitive to perturbation from a wide range of natural phenomena and human activities. The societal concern has been greatly enhanced in recent decades due to ever increasing pressures of population growth and industrialization. Chemical changes within the troposphere control a vast array of processes that impact human health, the biosphere, and climate. A main goal of tropospheric chemistry research is to measure and understand the response of atmospheric composition to natural and anthropogenic perturbations, and to develop the capability to predict future change. Atmospheric chemistry measurements are extremely challenging due to the low concentrations of critical species and the vast scales over which the observations must be made. Available tropospheric data are mainly from surface sites and aircraft missions. Because of the limited temporal extent of aircraft observations, we have very limited information on tropospheric composition above the surface. This situation can be contrasted to the stratosphere, where satellites have provided critical and detailed chemical data on the global distribution of key trace gases.

Singh, Hanwant B.↗
NASA NTRS2001

Microbial contamination of spacecraft

Spacecraft and space habitats supporting human exploration contain a diverse population of microorganisms. Microorganisms may threaten human habitation in many ways that directly or indirectly impact the health, safety, or performance of astronauts. The ability to produce and maintain spacecraft and space stations with environments suitable for human habitation has been established over 40 years of human space flight. An extensive database of environmental microbiological parameters has been provided for short-term (< 20 days) space flight by more than 100 missions aboard the Space Shuttle. The NASA Mir Program provided similar data for long-duration missions. Interestingly, the major bacterial and fungal species found in the Space Shuttle are similar to those encountered in the nearly 15-year-old Mir. Lessons learned from both the US and Russian space programs have been incorporated into the habitability plan for the International Space Station. The focus is on preventive measures developed for spacecraft, cargo, and crews. On-orbit regular housekeeping practices complete with visual inspections are essential, along with microbiological monitoring. Risks associated with extended stays on the Moon or a Mars exploration mission will be much greater than previous experiences because of additional unknown variables. The current knowledge base is insufficient for exploration missions, and research is essential to understand the effects of space flight on biological functions and population dynamics of microorganisms in spacecraft. Equally important is a better understanding of the immune response and of human-microorganism-environment interactions during long-term space habitation.

Mir Project↗
NASA NTRS2005

Microbiological Characterization and Concerns of the International Space Station Internal Active Thermal Control System

Since January 1999, the chemical the International Space Station Thermal Control System (IATCS) and microbial state of (ISS) Internal Active fluid has been monitored by analysis of samples returned to Earth. Key chemical parameters have changed over time, including a drop in pH from the specified 9.5 +/- 0.5 ta = 58.4, an increase in the level of total inorganic carbon (TIC), total organic carbon (TOC) and dissolved nickel (Ni) in the fluid, and a decrease in the phosphate (PO,) level. In addition, silver (AS) ion levels in the fluid decreased rapidly as Ag deposited on internal metallic surfaces of the system. The lack of available Ag ions coupled with changes in the fluid chemistry has resulted in a favorable environment for microbial growth. Counts of heterotrophic bacteria have increased from less than 10 colony-forming units (CFUs)/l00 mL to l0(exp 6) to l0(exp 7) CFUs/100 mL. The increase of the microbial population is of concern because uncontrolled microbiological growth in the IATCS can contribute to deterioration in the performance of critical components within the system and potentially impact human health if opportunistic pathogens become established and escape into the cabin atmosphere. Micro-organisms can potentially degrade the coolant chemistry; attach to surfaces and form biofilms; lead to biofouling of filters, tubing, and pumps; decrease flow rates; reduce heat transfer; initiate and accelerate corrosion; and enhance mineral scale formation. The micro- biological data from the ISS IATCS fluid, and approaches to addressing the concerns, are summarized in this paper.

Roman, Monsi C.↗
NASA NTRS2007

Risk Assessment of Physiological Effects of Atmospheric Composition and Pressure in Constellation Vehicles

To limit the risk of fire and reduce denitrogenation time to prevent decompression sickness to support frequent extravehicular activities on the Moon, a hypobaric (PB = 414 mmHg) and mildly hypoxic (ppO2 = 132 mmHg, 32% O2 - 68% N2) living environment is considered for the Crew Exploration Vehicle (CEV) and Lunar Surface Access Module (LSAM). With acute change in ppO2 from 145-178 mmHg at standard vehicular operating pressure to less than 125 mmHg at desired lunar surface vehicular operating pressures, there is the possibility that some crewmembers may develop symptoms of Acute Mountain Sickness (AMS). The signs and symptoms of AMS (headache plus nausea, dizziness, fatigue, or sleeplessness), could impact crew health and performance on lunar surface missions. An exhaustive literature review on the topic of the physiological effects of reduced ppO2 and absolute pressure as may contribute to the development of altitude symptoms or AMS was performed. The results of the nine most rigorous studies were collated, analyzed and contents on AMS and hypoxia symptoms summarized. There is evidence for an absolute pressure effect per se on AMS, so the higher the altitude for a given hypoxic alveolar O2 partial pressure (PAO2), the greater the AMS response. About 25% of adults are likely to experience mild AMS near 2,000 m altitude following a rapid ascent from sea level while breathing air (6,500 feet, acute PAO2 = 75 mmHg). The operational experience with the Shuttle staged denitrogenation protocol at 528 mmHg (3,048 m) while breathing 26.5% O2 (acute PAO2 = 85 mmHg) in astronauts adapting to microgravity suggests a similar likely experience in the proposed CEV environment. We believe the risk of mild AMS is greater given a PAO2 of 77 mmHg at 4,876 m altitude while breathing 32% O2 than at 1,828 m altitude while breathing 21% O2. Only susceptible astronauts would develop mild and transient AMS with prolonged exposure to 414 mmHg (4,876 m) while breathing 32% O2 (acute PAO2 = 77 mmHg). So the following may be employed for operational risk reduction: 1) develop procedures to increase PB as needed in the CEV, and use a gradual or staged reduction in cabin pressure during lunar outbound; 2) train crews for symptoms of hypoxia, to allow early recognition and consider pre-adaptation of crews to a hypoxic environment prior to launch, 3) consider prophylactic acetazolamide for acute pressure changes and be prepared to treat any AMS associated symptoms early with both carbonic anhydrase inhibitors and supplemental oxygen.

Scheuring, Richard A.↗
NASA NTRS2007

Microbiological Monitoring for the Constellation Program: Current Requirements and Future Considerations

Microbiological requirements for spaceflight are based on assessments of infectious disease risk which could impact crew health or mission success. The determination of risk from infectious disease is composed of several factors including (1) crew susceptibility, (2) crew exposure to the infectious disease agent, (3) the concentration of the infectious agent, and (4) the characteristics of the infectious agent. As a result of the Health Stabilization Program, stringent monitoring, and cleaning protocols, in-flight environmental microbial monitoring is not necessary for short-duration spaceflights. However, risk factors change for long-duration missions, as exemplified by the presence of medically significant organisms in the environments of both the Mir and International Space Station (ISS). Based upon this historical evidence, requirements for short duration usage aboard the Orion Crew Exploration Vehicle and Lunar Lander Vehicle will not require in-flight monitoring; however, as mission duration increases with a Lunar Outpost, an ability to detect microbial hazard will be necessary. The nature of the detection requirements will depend on the maturity of technology in a rapidly evolving marketplace. Regardless, the hardware will still need to maximize information to discipline experts and the crew, while minimizing the size, mass, power consumption, and crew time usage. The refinement of these monitors will be a major goal in our efforts to travel successfully to Mars.

Ott, C. Mark↗