Workshop Report: Developing a Research Agenda for the Energy Water Nexus

The energy water nexus has attracted public scrutiny because of the concerns about their interdependence and the possibility for cascading vulnerabilities from one system to the other. There are trends toward more water-­‐intensive energy (such as biofuels , unconventional oil and gas production, and regulations driving more water consumption for thermoelectric power production ) and more energy-­‐intensive water (such as desalination, or deeper ground water pumping and production). In addition demographic trends of population and economic growth will likely drive up total and per capita water and energy demand, and due to climate change related distortions of the hydrologic cycle, it is expected that the existing interdependencies will be come even more of a concern. Therefore, developing a research agenda and strategy to mitigate potential vulnerabilities and to meet economic and environmental targets for efficiently using energy and water would be very worthwhile. To address these concerns, the National Science Foundation (NSF) sponsored a workshop on June 10-­‐11, 2013 in Arlington, VA (at NSF headquarters) to bring together technical, academic, and industry experts from across the country to help develop such a research agenda. The workshop was sponsored by NSF Grant Number CBET 1341032 from the Division of Chemical, Bioengineering, Environmental and Transport Systems. Supporting programs were: Thermal Transport Processes, Environmental Sustainability, and Environmental Engineering.Center for Research in Water Resource

Toxic and contaminant concerns generated by Hurricane Katrina

Journal of Environmental Engineering-Asce, 132(6): pp. 565-566

Seasonal Toxicity Observed with Amphipods (Eohaustorius estuarius) at Paleta Creek, San Diego Bay, USA

To assess potential impacts on receiving systems, associated with storm water contaminants, laboratory 10‐d amphipod (Eohaustorius estuarius) survival toxicity tests were performed using intact sediment cores collected from Paleta Creek (San Diego Bay, CA, USA) on 5 occasions between 2015 and 2017. The approach included deposition‐associated sediment particles collected from sediment traps placed at each of 4 locations during the 2015 to 2016 wet seasons. The bioassays demonstrated wet season toxicity, especially closest to the creek mouth, and greater mortality associated with particles deposited in the wet season compared with dry season samples. Grain size analysis of sediment trap material indicated coarser sediment at the mouth of the creek and finer sediment in the outer depositional areas. Contaminant concentrations of metals (Cd, Cu, Hg, Ni, Pb, and Zn) and organic compounds (polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], and pesticides) were quantified to assess possible causes of toxicity. Contaminant concentrations were determined in the top 5 cm of sediment and porewater (using passive samplers). Whereas metals, PAHs, and PCBs were rarely detected at sufficient concentrations to elicit a response, pyrethroid pesticides were highly correlated with amphipod toxicity. Summing individual pyrethroid constituents using a toxic unit approach suggested that toxicity to E. estuarius could be associated with pyrethroids. This unique test design allowed delineation of spatial and temporal differences in toxicity, suggesting that storm water discharge from Paleta Creek may be the source of seasonal toxicity. Environ Toxicol Chem 2019;39:229–239. © 2019 SETACPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152638/1/etc4619_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152638/2/etc4619.pd

Advancing the use of passive sampling in risk assessment and management of contaminated sediments: Results of an international passive sampling inter-laboratory comparison

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practical guidance for standardized passive sampling, and advance the use of passive sampling in regulatory decision making by increasing confidence in the use of the technique. The study was performed by a consortium of 11 laboratories and included experiments with 14 passive sampling formats on 3 sediments for 25 target chemicals (PAHs and PCBs). The resulting overall interlaboratory variability was large (a factor of ∼10), but standardization of methods halved this variability. The remaining variability was primarily due to factors not related to passive sampling itself, i.e., sediment heterogeneity and analytical chemistry. Excluding the latter source of variability, by performing all analyses in one laboratory, showed that passive sampling results can have a high precision and a very low intermethod variability

Investigations of Transport in Complex Atmospheric Flow Systems. I. Small Scale Studies of Diffusion through Porous Media, Impact of Fumehood Exhaust Reentry on Indoor Air Quality, and Pollutant Transport Near an Isolated Island. II. Pollutant Transport in Mountain-Valley and Coastal Regions of California

This thesis details some applications of tracer techniques from laboratory scale studies of diffusion in porous media to the analysis of the transport and dispersion of pollutants in the mountain-valley and coastal environments that form the majority of the state of California. Chapter 1 describes a technique for estimating gaseous diffusivities in porous media that is based on the general solution to Fick's second law for diffusion in a tube between two well-mixed volumes. In beds of essentially non-porous particles, the ratio of the measured effective diffusivity to the air diffusivity of a gas was found to be proportional to the bed porosity raised to the 1.43 power, a result in agreement with previous studies on similar materials. High moisture content (>15-20% moisture in sand) was found to significantly reduce the gas diffusivity with respect to that found in dry materials. Chapter 2 indicates the importance of ventilation system imbalance upon the reentrainment of pollutants exhausted from a building. Tracer was released from a fumehood in a "clean" room at the Jet Propulsion Laboratory. Indoor concentrations as high as 235 PPB/gr-mole tracer released/hr were observed due to infiltration of the exhausted tracer. This concentration is about an order of magnitude higher than has been observed in buildings with more balanced ventilation systems. Predictions of single and multi-compartment stirred-tank models were compared to the dynamics of the tracer infiltration. A simple one-compartment model provided a better description of the infiltration dynamics than a three-compartment model suggested by the design of the ventilation system. Chapter 3 describes a series of atmospheric tracer studies of the transport and dispersion of pollutants over the ocean and near an isolated island cape. The experiments were designed to determine the impact of local sources on a background air quality sampling program. The horizontal dispersion of the tracer over the ocean surface could be approximated by the Gaussian plume model assuming a neutrally stable atmosphere, in general agreement with the expected atmospheric stability. Tracer releases from the surface of the isolated cape indicated that an essentially well-mixed separated zone existed above and downwind of the cape. The height of this zone extended to 35-40% above the height of the cape, about the same height as the wake downwind of an isolated building. Limited mixing between the separated zone and the freestream resulted in a sharp concentration gradient above this height. Chapter 5 indicates the difficulties of describing the behavior of pollutants in complex terrain. A series of tracer experiments conducted in the northern and central California Coastal Mountains are described. The Gaussian plume model could be used to describe the dispersion of the tracer during strong, unidirectional winds. During an elevated tracer release, however, wind directional shear with altitude led to plume bifurcation, with the majority being transported through a stable nighttime drainage layer to ground level. The transport through the stable layer occurred at a vertical velocity of about 2 cm/s, surprisingly rapid transport between stably stratified layers of the atmosphere. Chapter 6 describes the uncertainties associated with mass balance and Gaussian parameter estimates from tracer data. The uncertainty in the calculated final result can be less than the errors (assumed random) associated with any individual experimental measurement, indicating that such calculations can be made with greater accuracy than would initially be expected. Chapter 7 details the transport of pollutants in the San Joaquin Valley during stable wintertime conditions. The relatively limited net ventilation of the valley indicates that pollutants can remain within the valley for several days subsequent to their release. During one tracer experiment, about 50% of the released tracer was observed to be well-mixed within the southern valley about 72 hours after the beginning of the release. The most significant ventilation mechanism for the valley during the winter was the occasional passage of low pressure frontal systems. Long periods without frontal system passage can lead to significant pollutant buildup. Chapter 8 describes the transport of pollutants in the San Joaquin Valley during summertime conditions. While much more effectively ventilated than during the winter, the increased solar insolation leads to significant ozone levels within the valley. A strong influx of air at the northern mouth of the valley is balanced during the day by a corresponding efflux at its southern end and by daytime upslope flow on the Sierra Nevada Mountains. At night, an eddy forms in the southern valley due to low level stabilization and terrain blockage of the afternoon efflux over the southern boundary of the valley. This eddy grows as more air is entrained from the influx at the northern mouth of the valley. An accelerated layer of air aloft also develops during the night due to surface layer stabilization and decoupling. These dynamic flow structures are significant factors in the transport and dispersion of pollutants in the valley during the summer. Chapter 9 details the impact of the San Joaquin Valley on the northern Mojave Desert. The transport of pollutants from the southern valley was linked through both tracer and aerosol data to the rapid nighttime reduction in visibility in the northern Mojave Desert. Unlike winter conditions, most of the pollutants in the southern valley were transported out of the valley within a day after their release. Chapter 10 describes the impact on the Sierra Nevada Mountains of pollutant sources within the San Joaquin Valley. Tracer released within the valley was efficiently transported upslope, impacting National Park and Forest areas. The maximum concentrations observed upslope could be approximated with the Gaussian plume model, assuming very unstable atmospheric conditions. Nighttime stabilization arrested the upslope movement of the tracer and led to slope and valley impacts throughout the night. The limited nighttime ventilation of the slopes may result in the significant ozone concentrations typically observed at slope sites throughout the night. Chapter 11 describes the transport characteristics of the Sacramento Valley, the northern half of the California Central Valley. Tracer experiments indicated that San Francisco Bay area pollutants have only a small effect on the air quality in the Sacramento Valley. A midday flow divergence over Sacramento resulted in tracer impacts in both the northern part of the valley and the slopes northeast of the city. A counterclockwise eddy that forms in the southern valley during the morning was a potential mechanism for recirculating aged pollutants within the valley. During one tracer experiment, most of the released tracer was trapped within an elevated layer of air, a potentially important mechanism for multi-day impacts of pollutants. Chapter 12 evaluates the transport of pollutants in the Santa Barbara Channel off the coast of southern California. Limited vertical mixing combined with diurnal wind reversals resulted in multi-day onshore impacts of the tracer released offshore. Efficient lateral mixing of the tracer during wind reversals led to a widespread coastal impact from a single point source. The existence of many point sources could result in a diluted background concentration (i.e. after wind reversals) that equals or exceeds the concentration directly downwind of a single source. Chapter 13 develops a two layer model of the atmosphere that semi-quantitatively incorporates much of the basic transport structure observed in the above studies. The method of characteristics and the method of moments were used to examine the implications of the model. The model indicates that the air aloft must be considered in order to accurately predict the impact of a pollutant source, especially when considering the multi-day or long range impact of the source.</p

Modeling Compound Loss from Polydimethylsiloxane Passive Samplers

Volatile losses were measured from polydimethylsiloxane (PDMS) passive samplers during determination of contaminant porewater concentrations in sediments. Volatile losses could occur between the time of retrieval and processing of the passive sampler or in intertidal environments where the passive sampler could potentially be exposed above the water surface at low tide. A model was developed to predict losses of absorbed compounds as a function of sorbent geometry and the Henry’s Law Coefficient and PDMS-water partition coefficient of the compound of interest. The model suggests that thin layers of PDMS typically used to minimize equilibration times in passive sampling (≤30 µm) may not provide quantitative measurement of naphthalenes or other lighter volatile compounds without special efforts to reduce losses. The results suggest that the samplers should be processed rapidly onsite or kept at low temperatures after retrieval to maximize retention of more volatile compounds or designed with thick PDMS layers. The results also suggest that less volatile compounds, including phenanthrene, and higher molecular weight polynuclear aromatic hydrocarbons (PAHs) exhibit minimal evaporative losses with typical sample processing times

A Levy flight-random walk model for bioturbation

Levy flights are employed in a lattice model of contaminant migration by bioturbation, the reworking of sediment by benthic organisms. The model couples burrowing, foraging, and conveyor-belt feeding with molecular diffusion. The model correctly predicts a square-root dependence on bioturbation rates over a wide range of biomass densities. The model is used to predict the effect of bioturbation on the redistribution of contaminants in laboratory microcosms containing pyrene-inoculated sediments and the tubificid oligochaete Limnodrilus hoffmeisteri. The model predicts the dynamic flux from the sediment and in-bed concentration profiles that are consistent with observations. The sensitivity of flux and concentration profiles to the specific mechanisms of bioturbation are explored with the model. The flux of pyrene to the overlying water was largely controlled by the simulated foraging activities

Low-level amplification of oncogenes correlates inversely with age for patients with nontypical meningiomas

BACKGROUND: This study sought to identify genes in nontypical meningiomas with gains in copy number (CN) that correlate with earlier age of onset, an indicator of aggressiveness. METHODS: Among 94 adult patients, 91 had 105 meningiomas that were histologically confirmed. World Health Organization grades I (typical), II (atypical), and III (anaplastic) were assigned to tumors in 76, 14, and 1 patient, respectively. Brain invasion indicated that two World Health Organization grade I meningiomas were biologically atypical. DNA from 15 invasive/atypical/anaplastic meningiomas and commercial normal DNA were analyzed with multiplex ligation dependent probe amplification. The CN ratios (fold differences from normal) for 78 genes were determined. The CN ratio was defined as [tumor CN]/[normal CN] for each gene to normalize results. RESULTS: Characteristic gene losses (CN ratio \u3c 0.75) occurred in \u3e50% of the invasive/atypical/anaplastic meningiomas at 22q11, 1p34.2, and 1p22.1 loci. Gains (CN ratio ≥ 2.0) occurred in each tumor for 2 or more of 19 genes. Each of the 19 genes\u27 CN ratio was ≥ 2.0 in multiple tumors, and their collective sums (up to 49.1) correlated inversely with age (r = -0.72), minus an outlier. In patients ≤ 55 versus \u3e55 years, 5 genes (BIRC2, BRAF, MET, NRAS, and PIK3CA) individually exhibited significantly higher CN ratios (P \u3c 0.05) or a trend for them (P \u3c 0.09), with corrections for multiple comparisons, and their sums correlated inversely with age (r = -0.74). CONCLUSIONS: Low levels of amplification for selected oncogenes in invasive/atypical/anaplastic meningiomas were higher in younger adults, with the CN gains potentially underlying biological aggressiveness associated with early tumor development