Student Abstracts: Environmental Science at BNL

Determination of LC50 in Medaka Fish, Oryzias latipes, . YAHAIRA ARROYO (University of Puerto Rico at Cayey, Cayey, Puerto Rico 00731) RICHARD SETLOW (Brookhaven National Laboratory, Upton, NY 11973) .
It is hypothesized that pesticides can cause mutagenesis in living organisms. The purpose of this experiment was to determine the LC50 of pesticide Acetochlor for Medaka fish (Oryzias laptipes) at different times. Thirty adults fish Medaka HNI were separated equally into five, 400 mL beakers. Two hundred milliliters of filtered aquarium water were used at 4 different concentrations of Acetochlor (2.50mg/L, 12.50mg/L, 25.00mg/L, 50.00 mg/L). After placing the fish in each one of the beakers with different concentrations, the number of fish was counted at selected times (30 minutes, 15 hours, 24 hours, 40 hours, 48 hours, 72 hours, 96 hours, 120 hours). The time in which each fish died is used to determine the LC50 which is the lethal concentration of Acetochlor in which 50% of the fish died at a given time. Medaka fish will survive in concentration of up to 2 mg/L Acetochlor for 72-96 hours or 20 mg/L for 15 hours.

Land Use/Land Cover Map of the Central Facility of ARM Program in the Southern Great Plains using DOE?s Multispectral Thermal Imager (MTI) satellite images. . SUSAN BAEZ-CAZULL (University of Puerto Rico - Rio Piedres, San Juan, Puerto Rico 00931) ALICE CIALELLA (Brookhaven National Laboratory, Upton, NY 11973) .
Scientists studying global climate change collect and analyze data from a large array of instruments to study the effects and interactions of sunlight, radiant energy, and clouds on temperatures, weather and climate. Land Use/Land Cover maps provide information about soil moisture, land surface, and plant growth. This information can be used as ancillary data for instruments measuring energy balance, for studies in soil moisture and research on carbon fluxes affected by the vegetation. In this project, three satellite images from DOE's Multispectral Thermal Imager (MTI) taken in different seasons of 2000 provided the information to create a Land Use/Land Cover Map of the Central Facility of ARM site in the Southern Great Plains. Vegetation indices (NDVI) and Principal Components Analysis (PCA), along with ancillary data including Digital Orthophoto Quarter Quadrangles (DOQQs), other land maps, personal communications, and harvest tables were used to label the classes to create the final Land Use/Land Cover map. The 14 classes map which represent a seasonal land cover was created using a combined Multitemporal plus NDVI plus PCA image. The classes that are static (forest and water) were easily determined by their strong spectral and spatial characteristics in the NDVI, PCA, Near Infrared (NIR) and true color images. While the classes that change over the season (pasture/grass/hay, bare soil/buildings, and fallow) were the classes with the most confusion, due to their similar spectral characteristics. To improve this Land Use/Land Cover map additional ground truth data for 2000 will be needed.

Understanding Computed Microtomography. RYAN BUTRYN (Jamestown Community College, Jamestown, NY 14701) KEITH W. JONES (Brookhaven National Laboratory, Upton, NY 11973) .
The discovery of the X-ray and its ability to pass through opaque objects without damage has led to many important biological discoveries in the last century. Using the high intensity X-ray beam generated by the National Synchrotron Light Source at Brookhaven National Laboratory coupled with imaging computers, microtomography allows the viewing of previously unexplored microstructures. This technology proves useful in areas of geology, oceanography, and environmental biology with current research involved in analyzing porosity of sandstone samples. The recently developed stereographic viewing technology compliments computed microtomography producing stunning images that seemingly jump off the screen. Collecting microtomographic data suitable for visualization is a learned process involving control of beam energy in relation to sample density. Experimenting with instrument capabilities deepened understanding of synchrotron light and imaging technology. Computed Microtomography offers itself as a tool capable of supporting the three-dimensional data visualization field.

Woodlands at Brookhaven National Laboratory. JOSE GOMEZ (University of Puerto Rico, San Juan, Puerto Rico 00931) TIMOTHY GREEN (Brookhaven National Laboratory, Upton, NY 11973) .
The recent wildfires in New Mexico have highlighted the need to assess the fire potential of woodlands. In order to address this need data was collected at Brookhaven National Laboratory during the summer of 2001. The data included leaf litter, ladder fuel, hour fuels, and living vegetation. The woodlands analyzed included white pine, pine/oak, and oak/pine forests. A Rapid Environmental Assessment was carried out in each BNL sites in order to establish the factors necessary to determine fire potential. These factors include a consideration of both internal (ladder fuel, leaf litter, and duff) and external variables (temperature, wind speed, wind direction, and moisture). Although not considered here, terrain and canopy should be evaluated. Quadrats were established and random points sampled within each quadrat in all study sites. Fuel load was determined and the percentage of each component (pine needles, oak leaves, twigs etc.) noted. The understory was determined and the percentage of live vegetation was noted as a fire inhibitor. The depth of the duff was measured. Ladder fuel was determined as well as the percentage of one, ten, and one hundred hour fuels. The data indicates that there are distinct differences in the fire potential of each of these woodlands. This data has been used to prepare a predictive equation, which has the potential for accurately predicting the potential for fire in various woodland communities.

Which soil is the better water filter? . MIGUEL ROSARIO (Recinto Universitario de Magaguez, Magaguez, Puerto Rico 00681) TERRY SULLIVAN (Brookhaven National Laboratory, Upton, NY 11973) .
The Brookhaven Graphite Research Reactor, the world's first nuclear reactor dedicated to the peaceful exploration, is currently on an accelerated decommissioning schedule consisting in combining characterization with removal action for various systems and structures. If the characterization can provide enough information, then the canal's concrete structures and most of the soil around it can remain in place. Using the Environmental Visualization Systemâ to create three-dimensional images that visualize levels of soil contamination below the underground structures provides an effective tool to show with high confidence the locations where the hot spots (soils beneath the structures contain contaminant concentration above the regulatory clean-ups levels) of contamination are. Visualizations from the canal house and pile display some high concentration of soil contamination. Whereas it is likely that most of the canal soil were not contaminated above the regulatory clean-up levels. A tie-up process including three-dimensional visualization, risk assessments and others characterizations techniques will support an easier planning process including decisions that affect the extent removal and waste designation. With this the Decommissioning Project will have significant savings and reduced waste volumes for off-site disposal.

Synthesis and Detection of Hydrogen Peroxide and Methyl and Hydroxymethyl Peroxides. LUKE SHANNON (Dordt College, Sioux Center, IA 51250) JUDY LLOYD (Brookhaven National Laboratory, Upton, NY 11973) .
Knowledge of the concentrations of peroxides in the atmosphere is of interest to the atmospheric chemist. Hydrogen peroxide and organic peroxides are oxidants in their own right, and can also be used as a test of the oxidative capacity of the atmosphere. Several methods of detection were used in our laboratory. One method involves a continuous analyzer that used different reagents and different pH's to identify individual peroxides. Another method which involves HPLC separation followed by fluorescence detection of the respective hydroperoxides. The measurements of ambient air indicated the presence of H2O2, methyl hydroperoxide, and hydroxymethyl hydroperoxide. In this project, we used both methods to analyze laboratory standards of these peroxides. Due to their explosive nature when pure, a dilute aqueous solution of organic peroxides was desirable. A Co-60 source of -radiation was used to provide a dilute aqueous solution of methylhydroperoxide and H2O2. Hydroxymethyl hydroperoxide was synthesized in an equilibrium reaction involving HCHO and H2O2. These solutions were analyzed after separation by HPLC using fluorescence detection. The same samples were analyzed using the field instrument. Chromatograms from the HPLC method consistently and reproducibly showed the presence of the desired peroxides with adequate separation. The field instrument gave data that indicated the presence of an interfering factor. Elimination of this interference should prove to be relatively forthright. Future study into the HPLC method shows promise as a way to evaluate currently used field equipment and may be a feasible method of field data collection itself.

Understanding Computed Microtomography. DANIEL WESTFALL (Alfred State College, Alfred, NY 14802) KEITH W. JONES (Brookhaven National Laboratory, Upton, NY 11973) .
The discovery of the X-ray and its ability to pass through opaque objects without damage has led to many important biological discoveries in the last century. Using the high intensity X-ray beam generated by the National Synchrotron Light Source at Brookhaven National Laboratory coupled with imaging computers, microtomography allows the viewing of previously unexplored microstructures. This technology proves useful in areas of geology, oceanography, and environmental biology with current research involved in analyzing porosity of sandstone samples. The recently developed stereographic viewing technology compliments computed microtomography producing stunning images that seemingly jump off the screen. Collecting microtomographic data suitable for visualization is a learned process involving control of beam energy in relation to sample density. Experimenting with instrument capabilities deepened understanding of synchrotron light and imaging technology. Computed Microtomography offers itself as a tool capable of supporting the three-dimensional data visualization field.

Biochemical Conversion of Heavy Crude Oil. ELISHA WILLIAMS (Holyoke Community College, Holyoke, MA 01040) MOW LIN, PH.D. (Brookhaven National Laboratory, Upton, NY 11973) .
Petroleum will continue to play a major role as a transportation fuel in the coming decades. But, petroleum contains sulfur as one of its components. Burning sulfur results in an oxidized sulfur species that causes acid rain. Environmental regulations require that the sulfur be removed from the field prior to burning. Indeed, the U.S. E.P.A. has established the cleaner fuels and vehicles program, finalized in December 1999, which requires the sulfur content of diesel to be reduced by up to 90 percent. Conventional methods of removing sulfur include hydrodesulfurization, distillation, and hydrocracking. These methods of sulfur removal are costly and a search is underway to provide a method of sulfur removal that is more cost-efficient. Biochemical conversion of petroleum is one such method. In this method, natural bacteria are used to remove sulfur. In the biochemical conversion process, the bacteria reside in an aqueous phase that is mixed with a nonpolar hydrocarbon phase. In this case, the reaction occurs at the aqueous-hydrocarbon interface. During this process, the bacteria attack the sulfur containing aromatic rings and metabolize the sulfur. The goal of my research project was to evaluate a particular strain of bacteria for sulfur removal from a sample of heavy crude oil. In this study, the treated oil showed a marked decrease in the heavy fractions with a marked increase in the gasoline fractions over the untreated oil. If a bacterial strain is identified that will break up heavy fractions and metabolize sulfur in these heavy crudes, it could reduce the amount of money the refineries use in current conventional methods.