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At least 451 records · Page 25

Mercury and Radiocesium Accumulation and Associations With Sublethal Endpoints in the Florida Green Watersnake ( Nerodia floridana )

Mercury (Hg) and radiocesium ( 137 Cs) are well-known environmental contaminants with the potential to impact the health of humans and wildlife. Snakes have several characteristics conducive to studying environmental contamination but have rarely been included in the monitoring of polluted sites. We investigated the bioaccumulation of Hg and 137 Cs and associations with sublethal effects (standard metabolic rate [SMR] and hemoparasite infections) in Florida green watersnakes (Nerodia floridana). We captured 78 snakes from three former nuclear cooling reservoirs on the US Department of Energy's Savannah River Site in South Carolina (USA). For captured snakes, we (1) determined whole-body 137 Cs, (2) quantified total Hg (THg) using snake tail clips, (3) conducted hemoparasite counts, and (4) measured the SMR. We used multiple regression models to determine associations among snake body size, capture location, sex, tail THg, whole-body 137 Cs, Hepatozoon spp. prevalence and parasitemia, and SMR. Average whole-body 137 Cs (0.23 ± 0.08 Becquerels [Bq]/g; range: 0.00–1.02 Bq/g) was correlated with snake body size and differed significantly by capture site (Pond B: 0.67 ± 0.05 Bq/g; Par Pond: 0.10 ± 0.02 Bq/g; Pond 2: 0.03 ± 0.02 Bq/g). Tail THg (0.33 ± 0.03 mg/kg dry wt; range: 0.16–2.10 mg/kg) was significantly correlated with snake body size but did not differ by capture site. We found no clear relationship between SMR and contaminant burdens. However, models indicated that the prevalence of Hepatozoon spp. in snakes was inversely related to increasing whole-body 137 Cs burdens. Our results indicate the bioaccumulation of Hg and 137 Cs in N. floridana and further demonstrate the utility of aquatic snakes as bioindicators. Furthermore, our results also suggest a decrease in Hepatozoon spp. prevalence related to increased burdens of 137 Cs. Although the results are intriguing, further research is needed to understand the dynamics between 137 Cs and Hepatozoon spp. infections in semiaquatic snakes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Reliability-informed end-of-use decision making for product sustainability using two-stage stochastic optimization

The concept of circular economy has been diffused in recent decades to promote economic growth that does not add to the burden on natural resource extraction. Re-X options (e.g., reuse, repair, refurbish, remanufacture, recycle) have been gradually adopted in the product development process and optimized to reduce or eliminate waste and pollution. Although manufacturing incorporating Re-X options can be more environmentally friendly, it involves more sources of uncertainty than traditional manufacturing since the end-of-use products can be collected from multiple origins with various quantities and qualities, and the market demand for both new and remanufactured products cannot be forecasted perfectly. Thus, there is a need to optimize the Re-X policy to alleviate the negative impacts of the higher uncertainty. One option is using the reliability information of new products to estimate the end-of-use conditions and applying multi-stage stochastic optimization to capture multiple demand scenarios. This paper develops a two-stage stochastic optimization model to optimize the quality thresholds for reuse, recycling, and remanufacturing options. Our objective is to minimize the total cost, energy consumption, and environmental impact of producing and providing warranty service for a product family. The model employs reliability information of product components to estimate the warranty service cost and the end-of-use conditions of the returned resources. A case study on a general product family is implemented to illustrate the efficacy of the optimization model. Finally, results show that the two-stage optimization can achieve cost and environmental impact reduction for a hybrid manufacturing and remanufacturing process.

97 MATHEMATICS AND COMPUTING↗

Multi-campaign ship and aircraft observations of marine cloud condensation nuclei and droplet concentrations

In situ marine cloud droplet number concentrations (CDNCs), cloud condensation nuclei (CCN), and CCN proxies, based on particle sizes and optical properties, are accumulated from seven field campaigns: ACTIVATE; NAAMES; CAMP 2 EX; ORACLES; SOCRATES; MARCUS; and CAPRICORN2. Each campaign involves aircraft measurements, ship-based measurements, or both. Measurements collected over the North and Central Atlantic, Indo-Pacific, and Southern Oceans, represent a range of clean to polluted conditions in various climate regimes. With the extensive range of environmental conditions sampled, this data collection is ideal for testing satellite remote detection methods of CDNC and CCN in marine environments. Remote measurement methods are vital to expanding the available data in these difficult-to-reach regions of the Earth and improving our understanding of aerosol-cloud interactions. The data collection includes particle composition and continental tracers to identify potential contributing CCN sources. Several of these campaigns include High Spectral Resolution Lidar (HSRL) and polarimetric imaging measurements and retrievals that will be the basis for the next generation of space-based remote sensors and, thus, can be utilized as satellite surrogates.

54 ENVIRONMENTAL SCIENCES↗

EMP, Attachment 3: Dose Assessment Guidance

This Dose Assessment Guidance (DAG) describes methods used to comply with the reporting requirements for dose to an individual member of the public receptor, collective dose, and biota dose for radionuclide air emissions under the U.S. Department of Energy, Office of Science, Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP). The National Emission Standards for Hazardous Air Pollutants (40 CFR 61), Subpart H, is the greatest driver for the requirements. This DAG applies to public dose from radioactive material releases to the air from PNNL Richland Campus and PNNL Sequim Campus. Dose determinations from Richland Campus surveillance of ambient external dose and ambient air particulates is also briefly discussed. This guidance is Attachment 3 to PNNL’s EMP (PNNL-20919) and addresses a discrete, vital subject area of the EMP that is subject to revision independent of the main text of the EMP document.

40 CFR 61 Subpart H↗

EMP Attachment 3: Dose Assessment Guidance (Rev.3)

This Dose Assessment Guidance (DAG) describes methods used to comply with the reporting requirements for dose to an individual member of the public receptor, collective dose, and biota dose for radionuclide air emissions under the U.S. Department of Energy, Office of Science, Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP). The National Emission Standards for Hazardous Air Pollutants (40 CFR 61), Subpart H, is the greatest driver for the requirements. This DAG applies to public dose from radioactive material releases to the air from PNNL-Richland Campus and PNNL Marine and Coastal Research Laboratory. Dose determinations from Richland Campus surveillance of ambient external dose and ambient air particulates is also briefly discussed. This guidance is Attachment 3 to PNNL’s EMP (PNNL-20919) and addresses a discrete, vital subject area of the EMP that is subject to revision independent of the main text of the EMP document.

40 CFR 61 Subpart H↗

EMP, Attachment 3: Dose Assessment Guidance (Rev.4)

This Dose Assessment Guidance (DAG) describes methods used to comply with the reporting requirements for dose to an individual member of the public receptor, collective dose, and biota dose for radionuclide air emissions under the U.S. Department of Energy, Office of Science, Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP). The National Emission Standards for Hazardous Air Pollutants (40 CFR 61), Subpart H, is the greatest driver for the requirements. This DAG applies to public dose from radioactive material releases to the air from PNNL-Richland campus and PNNL-Sequim campus. Dose determinations from Richland campus surveillance of ambient external dose and ambient air particulates is also discussed. This guidance is Attachment 3 to PNNL’s EMP (PNNL-20919) and addresses a discrete, vital subject area of the EMP that is subject to revision independent of the main text of the EMP document.

40 CFR 61 Subpart H↗

Systems integration studies for supersonic cruise aircraft

Technical progress in each of the disciplinary research areas affecting the design of supersonic cruise aircraft is discussed. The NASA AST/SCAR Program supported the integration of these technical advances into supersonic cruise aircraft configuration concepts. While the baseline concepts reflect differing design philosophy, all reflect a level of economic performance considerably above the current foreign aircraft as well as the former U.S. SST. Range-payload characteristics of the study configurating show significant improvement, while meeting environmental goals such as takeoff and landing noise and upper atmospheric pollution.

Mascitti, V. R.↗

SPINOFF 2000

For the past 42 years, NASA has made special efforts to ensure the widest possible dissemination of its research and technology developments. We share the wealth of technology developed for our missions with the nation's industries to contribute to US economic strength and quality of life. For the past 27 years, this publication has provided you with over 1,200 examples of products and services developed as a direct result of commercial partnerships between NASA and the business community. Examples have covered products from fire retardant materials and air pollution monitors to non-invasive cardiac monitors and sensors for environmental control. In the Technology Transfer and Outreach section of Spinoff 2000, we highlight the activities of our Ames Research Center's Commercial Technology Office (CTO). Their efforts to facilitate and support technology commercialization are representative of the CTO at each field center. Increased activities to accelerate the dissemination of technologies, speed up the process of patent licensing, quicken the release of software for beta testing, support and manage incubators, and hasten the collaboration with commercial and academic organizations will continue to maximize the earliest potential commercial utilization of NASA's new inventions and technologies. Spinoff 2000 is organized into three sections: (1) Aerospace and Development highlights major research and development efforts currently carried out at the 10 NASA field centers; (2) Commercial Benefits-Spinoffs describes commercially available products and services resulting from the transfer of NASA technology; and (3) Technology Transfer and Outreach features this year's center spotlight, NASA's Ames Research Center, and its commercialization efforts, as well as the mechanisms in place nationwide to assist US industry in obtaining, transferring, and applying NASA technology, expertise, and assistance.

Source record↗

Portable Gas Analyzer

The Michromonitor M500 universal gas analyzer contains a series of miniature modules, each of which is a complete gas chromatograph, an instrument which separates a gaseous mixture into its components and measures the concentrations of each gas in the mixture. The system is manufactured by Microsensor Technology, and is used for environmental analysis, monitoring for gas leaks and chemical spills, compliance with pollution laws, etc. The technology is based on a Viking attempt to detect life on Mars. Ames/Stanford miniaturized the system and NIOSH funded further development. Three Stanford researchers commercialized the technology, which can be operated by unskilled personnel.

Source record↗

[Corrected Title: Solid-Phase Extraction of Polar Compounds from Water] Automated Electrostatics Environmental Chamber

A solid-phase extraction (SPE) process has been developed for removing alcohols, carboxylic acids, aldehydes, ketones, amines, and other polar organic compounds from water. This process can be either a subprocess of a water-reclamation process or a means of extracting organic compounds from water samples for gas-chromatographic analysis. This SPE process is an attractive alternative to an Environmental Protection Administration liquid-liquid extraction process that generates some pollution and does not work in a microgravitational environment. In this SPE process, one forces a water sample through a resin bed by use of positive pressure on the upstream side and/or suction on the downstream side, thereby causing organic compounds from the water to be adsorbed onto the resin. If gas-chromatographic analysis is to be done, the resin is dried by use of a suitable gas, then the adsorbed compounds are extracted from the resin by use of a solvent. Unlike the liquid-liquid process, the SPE process works in both microgravity and Earth gravity. In comparison with the liquid-liquid process, the SPE process is more efficient, extracts a wider range of organic compounds, generates less pollution, and costs less.

Sauer, Richard↗

Multi-Campaign Ship and Aircraft Observations of Marine Cloud Condensation Nuclei and Droplet Concentrations

In-situ marine cloud droplet number concentrations (CDNCs), cloud condensation nuclei (CCN), and CCN proxies, based on particle sizes and optical properties, are accumulated from seven field campaigns: ACTIVATE; NAAMES; CAMP2EX; ORACLES; SOCRATES; MARCUS; and CAPRICORN2. Each campaign involves aircraft measurements, ship-based measurements, or both. Measurements collected over the North and Central Atlantic, Indo-Pacific, and Southern Oceans, represent a range of clean to polluted conditions in various climate regimes. With the extensive range of environmental conditions sampled, this data collection is ideal for testing satellite remote detection methods of CDNC and CCN in marine environments. Remote measurement methods are vital to expanding the available data in these difficult-to-reach regions of the Earth and improving our understanding of aerosolcloud interactions. The data collection includes particle composition and continental tracers to identify potential contributing CCN sources. Several of these campaigns include High Spectral Resolution Lidar (HSRL) and polarimetric imaging measurements and retrievals that will be the basis for the next generation of space-based remote sensors and, thus, can be utilized as satellite surrogates.

Atmospheric chemistry↗

Spatial Variation of Fine Particulate Matter Levels in Nairobi Before and During the COVID-19 Curfew: Implications for Environmental Justice

The temporary decrease of fine particulate matter (PM(sub 2.5)) concentrations in many parts of the world due to the COVID-19 lockdown spurred discussions on urban air pollution and health. However there has been little focus on sub-Saharan Africa, as few African cities have air quality monitors and if they do, these data are often not publicly available. Spatial differentials of changes in PM(sub 2.5) concentrations as a result of COVID also remain largely unstudied. To address this gap, we use a serendipitous mobile air quality monitoring deployment of eight Sensirion SPS 30 sensors on motorbikes in the city of Nairobi starting on 16 March 2020, before a COVID-19 curfew was imposed on 25 March and continuing until 5 May 2020. We developed a random-forest model to estimate PM(sub 2.5) surfaces for the entire city of Nairobi before and during the COVID-19 curfew. The highest PM(sub 2.5) concentrations during both periods were observed in the poor neighborhoods of Kariobangi, Mathare, Umoja, and Dandora, located to the east of the city center. Changes in PM(sub 2.5) were heterogeneous over space. PM(sub 2.5) concentrations increased during the curfew in rapidly urbanizing, the lower-middle-class neighborhoods of Kahawa, Kasarani, and Ruaraka, likely because residents switched from LPG to biomass fuels due to loss of income. Our results indicate that COVID-19 and policies to address it may have exacerbated existing air pollution inequalities in the city of Nairobi. The quantitative results are preliminary, due to sampling limitations and measurement uncertainties, as the available data came exclusively from low-cost sensors. This research serves to highlight that spatial data that is essential for understanding structural inequalities reflected in uneven air pollution burdens and differential impacts of events like the COVID pandemic. With the help of carefully deployed low cost sensors with improved spatial sampling and at least one reference-quality monitor for calibration, we can collect data that is critical for developing targeted interventions that address environmental injustice in the African context.

Environmental justice↗

Environmentally-driven Materials Obsolescence: Material Replacements and Lessons Learned from NASA's Space Shuttle Program

The Space Shuttle Program was terminated in 2011 with the last flight of the Shuttle Endeavour. During the 30 years of its operating history, the number of domestic and international environmental regulations increased rapidly and resulted in materials obsolescence risks to the program. Initial replacement efforts focused on ozone depleting substances. As pressure from environmental regulations increased, Shuttle worked on the replacement of heavy metals. volatile organic compounds and hazardous air pollutants. Near the end of the program. Shuttle identified potential material obsolescence driven by international regulations and the potential for suppliers to reformulate materials. During the Shuttle Program a team focused on environmentally-driven materials obsolescence worked to identify and mitigate these risks. Lessons learned from the Shuttle experience can be applied to new NASA Programs as well as other high reliability applications.

Meinhold, Anne↗

Science Overview

This report presents an overview of the latest scientific consensus understanding of the effect of aviation emissions on the atmosphere for both local air quality and climate change in order to provide a contextual framework for raising future questions to help assess the environmental benefits of technology goals. The questions may take the form of what are the environmental benefits that would result if goals are achieved, what are the consequences for other aviation pollutants, and whether tools exist to evaluate the trade-off. In addition to this documents, presentations will be made at the meeting to illustrate current developing views on these subjects. To facilitate studies on trade-offs among environmental impacts from aviation, one must start with scientific investigations that quantify the impacts. A second step is to select representative metrics with policy relevance so that diverse impacts can be put on the same common scale. The IPCC Special Report on Aviation (IPCC, 1999) serves as an excellent example of the first step. The report was produced by IPCC's Working Group 1, whose mandate is to provide the assessment of the scientific aspects of the climate system and climate change. An example of the second step is Witt et al. (2005), a study commissioned by the Environment DG of the European Commission. Within the context of CAEP, step 1 is aligned with the responsibilities of the Research Focal Points, while step 2 is more related to activities of FESG. These steps are likely to be iterative as proposed policy options will raise new science questions, and new science will expand or limit policy options. Past experiences show that clearly defined policy-related scientific needs will help focus the scientific community to marshal their intellects to provide the needed answers.

Bruning, Claus↗

Estuarine nutrient pollution impact reduction assessment through euphotic zone avoidance/bypass considerations

The feasibility of reducing nutrient pollution impact by redirecting the effluent to depths below the euphotic zone was investigated for the deep estuarine Puget Sound region of the Salish Sea in the Pacific Northwest of America. The hypothesis tested was that the thickness of the outflow layer in deep estuaries may be greater than the euphotic zone depth, allowing a fraction of nutrients to be exported out passively through the layers immediately below. The euphotic zone depth in Puget Sound varies from 8 to 25 m while the depth of the outflow layer can reach up to ≈ 60 m. Outfall relocation strategies were tested on 99% of the anthropogenic nutrient loads currently delivered to Puget Sound. The impact was quantified using the previously established biophysical Salish Sea Model, using gross primary production and exposure to low dissolved oxygen (DO) levels as the metric (< 2 mg/L for hypoxia and < 5 mg/L for impairment). Eliminating nutrient pollution (above natural) from rivers and wastewater reduced hypoxia exposure by 8.1% and 11.2%, respectively. Relocating the outfalls to deeper waters resulted in improvements, but only in the sill-less sub-basins such as Whidbey, where hypoxia and DO impairment exposure decreased (7.9% and 6.8%, respectively). The presence of multiple sills and circulation cells in Puget Sound resulted in increased exposure and rendered nutrient bypass goals unfeasible as originally envisioned. However, an alternate nutrient export pathway was identified through bottom exchange flow out of Puget Sound via Whidbey Basin and Deception Pass. An unexpected reduction in the exchange outflow magnitude (≈ 4%) due additional (22%) freshwater discharged to the estuary bottom was also noted. The potential loss in circulation strength due to rerouting of natural surface freshwater through submerged deep-water outfalls is identified as a new unforeseen anthropogenic impact.

54 ENVIRONMENTAL SCIENCES↗

Metallurgical Evaluations of Depainting Processes on Aluminum Substrate

In December 1993, the Environmental Protection Agency (EPA) Emission Standards Division and the National Aeronautics and Space Administration's (NASA's) Marshall Space Flight Center (MSFC) signed an Interagency Agreement (IA) initiating a task force for the technical assessment of alternative technologies for aerospace depainting operations. The United States Air Force (USAF) joined the task force in 1994. The mandates of the task force were: (1) To identify available alternative depainting systems that do not rely on methylene chloride or other ozone-depleting, chlorinated, and volatile organic carbon solvents. (2) To determine the viability, applicability, and pollution prevention potential of each identified alternative. (3) To address issues of safety, environmental impact, reliability, and maintainability. Through a Technical Implementation Committee (TIC), the task force selected and evaluated eight alternative paint stripping technologies: chemical stripping, carbon dioxide (CO2) blasting, xenon flashlamp and CO2 coatings removal (FLASHJET(R)), CO2 laser stripping, plastic media blasting (PMB), sodium bicarbonate wet stripping, high-pressure water blasting (WaterJet), and wheat starch abrasive blasting (Enviro-Strip(R)). (The CO2 blasting study was discontinued after the first depainting sequence.) This final report presents the results of the Joint EPA/NASA/USAF Interagency Depainting Study. Significant topics include: (1) Final depainting sequence data for the chemical stripping, PMB, sodium bicarbonate wet stripping, and WaterJet processes. (2) Strip rates for all eight technologies. (3) Sequential comparisons of surface roughness measurements for the seven viable depainting technologies. (4) Chronological reviews of and lessons learned in the conduct of all eight technologies. (5) An analysis of the surface roughness trends for each of the seven technologies. (6) Metallurgic evaluations of panels Summaries of corrosion and hydrogen embrittlement evaluations of chemical stripping panels, detailed descriptions of which appear in previous reports. Because the requirements for alternative systems are diverse, as are initial setup, training, and on-going operational considerations, this study does not recommend a particular product or process. Users of this study will draw their own conclusions from the data presented herein.

McGill, Preston↗

Comparison of Satellite Observations of Aerosol Optical Depth to Surface Monitor Fine Particle Concentration

Under NASA's Earth Science Applications Program, the Infusing satellite Data into Environmental Applications (IDEA) project examined the relationship between satellite observations and surface monitors of air pollutants to facilitate a more capable and integrated observing network. This report provides a comparison of satellite aerosol optical depth to surface monitor fine particle concentration observations for the month of September 2003 at more than 300 individual locations in the continental US. During September 2003, IDEA provided prototype, near real-time data-fusion products to the Environmental Protection Agency (EPA) directed toward improving the accuracy of EPA s next-day Air Quality Index (AQI) forecasts. Researchers from NASA Langley Research Center and EPA used data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument combined with EPA ground network data to create a NASA-data-enhanced Forecast Tool. Air quality forecasters used this tool to prepare their forecasts of particle pollution, or particulate matter less than 2.5 microns in diameter (PM2.5), for the next-day AQI. The archived data provide a rich resource for further studies and analysis. The IDEA project uses data sets and models developed for tropospheric chemistry research to assist federal, state, and local agencies in making decisions concerning air quality management to protect public health.

Kleb, Mary M.↗

Combining Chemistry, Material Science, Inspiration from nature, and Serendipity to Develop Stimuli-responsive Polymeric Materials

Neither of us can remember people talking about stimuli-responsive polymers when we were students. Even though this was still in the last century, it was almost 70 years after Staudinger's seminal paper "uber Polymerisation"![1] By the time we entered graduate school in the early 1990 s, the first papers on polymer light emitting diodes appeared, while research on electrically conducting, nonlinear optical, and other "functional" polymers was already in full swing. Looking back, there were some stimuli-responsive materials that were around at the time, but it took the better part of the last 30 years until the field had developed into what we think is one of the most vibrant areas of polymer science. Before the potential usefulness of this class of materials was recognized, researchers were focused on developing polymeric materials that would not respond to external influences, and in fact maintain (in particular) their mechanical properties in a wide range of environments. This has led to the development of many environmentally robust polymers, which have come to impact basically every aspect of our daily life. Ironically, this long-sought stability now comes back to haunt us in the form of plastic pollution, but this is another story. The concept of materials that adapt their properties in response to changing environmental conditions might appear like a complete reversal with respect to the original goals of creating stable materials. However, eventually a) it was recognized that materials that respond to a specific stimulus in a predictable and useful manner would significantly broaden the potential usefulness of polymers, and b) the field of polymer science had developed to the point where the rational design, preparation, and characterization of such materials became possible. The expression 'stimuli-responsive polymer' had been first used in the 1980's, however its use really only gained popularity a few decades later. In the early days, terms such as environmentally-sensitive or environmentally-responsive polymers, stimuli-reversible or stimuli-sensitive polymers, or polymers with phase transitions have also been used.

Rowan, Stuart J.↗