Analysis of the San Joaquin River: An Example of Techniques and Parameters Used in Assessing Levels of Water Quality. KATHLEEN HUTCHISON (University of Rochester Rochester, NY 14627) WILLIAM T. STRINGFELLOW (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

It is important to be able to quantify water quality in order to talk about and set goals for impaired water bodies. However, water quality remains difficult to define, and the important aspects of the quality of a given water body changes from case to case. One fundamental component unfailingly taken into consideration is the effect on aquatic life. An example of a water body classified as impaired is the San Joaquin River (SJR), which is cited for its critically low dissolved oxygen (DO) levels. The DO sag has harmfully impacted Chinook salmon in the area. Large blooms of algae upstream of the Stockton Deep Water Ship Channel are believed to be related to the significantly low DO levels. In this study, six parameters related to algal growth and water quality are measured at 20 sites along the SJR and its tributaries, and a water quality ranking of the different sites is produced. The result is that a clearer picture of relative areas of water quality can be better deciphered, and some sites in particular are prioritized for further study.

Effects of Temperature and Relative Humidity of Indoor Air on Workers' Health in U.S. Office Buildings. PENGQIAN YUAN (University of California, Berkeley Berkeley, CA 94720) MARK J. MENDELL (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

It is unknown how the thermal properties of indoor air within buildings affects the health of the buildings' workers. In order to find this relationship, temperature and relative humidity (RH) data within 100 buildings across the United States were compiled and merged with lower respiratory symptom outcomes surveyed amongst office workers within each building using a statistical analysis software, SAS. After obtaining a new variable, humidity ratio, from temperature and relative humidity in order to decrease dependence of both these variables, bivariate analyses were conducted on each lower respiratory symptom (cough, shortness of breath, tightness of chest, and wheeze) and on the overall lower respiratory group response. Following the analyses, odds ratio estimates were plotted against the temperatures and humidity ratios categorized into five ranges for each symptom. It was seen that the trendlines of the symptoms versus temperature outcomes all appeared to be concave parabolas. It is held that there is possibly an ideal temperature in which workers have the fewest lower respiratory symptoms. The odds ratios estimates versus humidity ratios were not as consistent as the trends for symptoms against temperature and also had greater noise. Therefore, it did not give enough evidence for a concrete conclusion. Further studies will be needed to test for confounding variables and will contain multivariate analyses with variables such as age and gender. This work is only a small portion of indoor air study as analyses on other symptom groups such as upper respiratory, mucous membranes, and neurological outcomes are needed as well.

Evaluating the Effects of Tailwater Irrigation on Soil Salinity and Discharge Water Quality. HEATHER GRAHAM (Occidental College Los Angeles, CA 90041) NIGEL WT QUINN (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Inorganic salts are a natural component of soil that arise during the process of geologic erosion. Typically, rainwater naturally leaches salts into lower portions of the soil profile. However, in arid regions such as the San Joaquin River Basin of California, lack of rainfall and climatic conditions increase surface evaporation and upward capillary flow resulting in reduced leaching. The geologic composition of this area causes both the soil and surface water to be saline. Because of this, agricultural runoff is highly saline and detrimental to receiving water bodies. The excess salt in water can harm aquatic organisms and cause problems for downstream users. State regulations limit the amount of salts that agricultural users are permitted to discharge into receiving waters. In order to comply with these regulations irrigation districts are exploring techniques and technologies that can improve drain water quality without increasing soil salinity. This study examines the use of agricultural runoff or 'tailwater' as an irrigation water source. Four sites were chosen within the Patterson Irrigation District in the San Joaquin River Basin that have similar irrigation, surface drainage and crop histories but different water sources of varying quality one of which is tailwater. An EM salinity survey of each field revealed that while irrigation water is generally proportional to soil salinity other factors were affecting the salt level. A field receiving irrigation water 27% more saline than another had the same soil salinity but likely had better subsurface drainage. Flow and EC data at the drain site into the river before and after implementation of the tailwater recovery system indicated a 47% decrease in salt discharge into the river. This study suggests that with proper drainage and soil management tailwater can be used as a source of irrigation water. Tailwater recycling also decreases quantity of discharge water as well as improving the overall quality.

Improving the Accuracy of Real-Time Black Carbon Measurements. OLIVIA HAESLOOP (Yale University New Haven, CT 06520) TOM KIRCHSTETTER (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

In order to better understand the health and climate impacts of aerosol black carbon (BC), this project began calibration of the aethelometer, the most widely used instrument for real-time BC measurements. The aethelometer measures light attenuation (ATN) through a filter upon which aerosols are collected, then calculates the amount of BC using the equation BC = ATN/ , where is the attenuation coefficient, given by the manufacturer as16.6 m2/g (at 880nm). Recent studies, however, raise doubt that is constant but rather support a calibration of as a decreasing function of particle loading. Initial tasks carried out in this project to improve BC measurements were the assessment of a filter effect on apparent measured absorption and the assessment of the aethelometer given a source of pure BC. To study the filter effect, flame samples were collected from a constant, highly stable inverted flame using four filter lots. No apparent difference was found between filter lots. Subsequently, to assess the aethelometer given a BC source only, one filter lot collected samples from the steady flame and was compared to the readings taken in parallel by the aethelometer. Initial filter data confirms a steady BC output by the flame while the aethelometer shows a cyclical decrease of BC due to the incorrect calibration. Further study is necessary to quantify the relationship between ATN and BC, as well as future experiments evaluating the aethelometer in the presence of mixed aerosol sources and diesel emissions.

Long Term Impacts of Fire on Grassland Carbon Balance. LAURA WELLS (University of Colorado Boulder, CO 80305) MARGARET TORN (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

I analyzed soil and vegetation samples from the Southern Great Plains (SGP) test bed in Oklahoma for C, N, and ¹³C to establish total ecosystem carbon estimates for a burn experiment. The experiment aims to uncover the long term effects of fire on the grassland ecosystem carbon balance. This is important on two levels. First, because fire could change the rate of photosynthesis and respiration of vegetation due to loss of biomass or change in community composition, fire management could impact global climate change. Second, if in fact fire is a significant factor, grassland is the most widely found ecosystem in the SGP and holds proportionally more carbon than other ecosystems, so it is of strategic importance. This experiment is designed with two fields, one was burned to assess the post fire ecosystem carbon changes and the other was kept unburned as a control to quantify future changes. However, in order to establish that fire was the cause of any changes, we must establish that the sites were statistically the same before the fire. This was achieved by analyzing soil and vegetation samples from both fields for %C, %N, and ¹³ C using an elemental analyzer and a mass spectrometer. Ten replicate quadrants per field were sampled by on-site staff for seven classes of vegetation and litter. Preliminary data from the vegetation analysis shows that the fields are in fact statistically similar, with C and ¹³C values for each field falling with in the other's standard error. This indicates that any differences in the fields after the fire will in fact be a result of the burn. The sites were managed by the USDA Grazing land Research Laboratory and the project was sponsored by the DOE Atmospheric Radiation Measurement Program.

Measuring Algal Biomass and Rate of Growth by Chlorophyll Fluorescence. ADAM BARLEV (Contra Costa College San Pablo, CA 94806) WILL STRINGFELLOW (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Dissolved oxygen (DO) is one of the primary indicators of aquatic habitat health. Dangerously low DO has been reported in the San Joaquin River (SJR) downstream from Stockton, California. Studies examining the dissolved oxygen problem have identified several factors that cause low DO, including algae blooms stimulated by fertilizers from agricultural runoff upstream, bacterial oxidation of ammonia released from the Stockton wastewater treatment plant, and the deepening and widening of the river itself. These studies were limited by available methods for algae measurements. The primary methods of measuring algal biomass are direct cell counts and chlorophyll extraction, both of which are time consuming and complicated, which increases chances for operator error. An alternative method for algal measurement was investigated. Chlorophyll has a fluorescent signal proportional to concentration. An experiment was performed to correlate fluorescence to the standard methods for algae quantification. Algae from a tributary to the SJR were cultured in the lab under constant illumination. Their growth was measured by chlorophyll fluorescence, OD590, and direct cell counts. The fluorescence method was also applied to field samples from the SJR and many of its tributaries in parallel with the chlorophyll extraction procedure. The relationship between chlorophyll fluorescence and chlorophyll concentration as measured by extraction was linear. However, when fluorescence was compared to direct cell counts, the proportionality was not linear for higher cell counts. This indicates that the chlorophyll per cell decreases with the age of a cell culture. This result is significant for the study because low DO occurs primarily during the algae's highest concentration. The results of this experiment will be combined with other experiments to define the relationship between chlorophyll concentration and algae biomass that takes into account the age of the culture.

Particulate Carbon and Gas/Particle Partitioning of Aromatic Hydrocarbons in Seattle. JEFF DUARTE (Shasta Community College Redding, CA 96001) LARA A. GUNDEL (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

A correlation between airborne particulate pollutants and increasing counts of respiratory and circulatory illness has the U.S. Environmental Protection Agency searching for accurate methods of assessing human exposure to particulate carbon. Depending on location, particulate carbon makes up 30-50% of the total particulate mass in the atmosphere. Using the integrated organic gas and particle sampler (IOGAPS), this study seeks to minimize sampling artifacts and to find a relationship between organic and elemental carbon (OC and EC) and polycyclic aromatic hydrocarbon (PAH) concentrations as an approach to particulate carbon exposure determination.It was found that the hypothesis was supported by the data: without a denuder in the sampling method pathway to separate/collect SVOC (semi-volatile compounds), sampling artifacts formed which complicated the research.

Stress Response Phenomics in Desulfovibrio vulgaris Ferric Uptake Regulator (FUR) Mutants. KAREN WEBSTER (University of California, Berkeley Berkeley, CA 94720) TERRY C. HAZEN (Lawrence Berkeley National Laboratory, Berkley, CA, 94720)

Bioremediation is potentially a very powerful technique for containment of hazardous waste, particularly metals and radionuclides. Controlling and manipulating naturally-occuring microorganisms to handle hazardous waste would be effective, cost-efficient and environmentally sound, especially compared with other remediation techniques. Before the organisms can be properly applied to contaminated sites, they must be fully studied and characterized. One microorganism, Desulfovibrio vulgaris Hildenborough (DvH), is particularly promising for use in remediation efforts. To understand this organism's capabilities and application potential, it is first necessary to study and elucidate its phenotypical characteristics and optimal growth environment. Special DvH mutants (JW707) have been designed lacking a specific, metabolically significant, ferric uptake regulator gene. By comparing these altered DvH phenotypes to those of the wild-type we can elucidate the significance of the "knocked-out" gene and it's relation to DvH stress response. Stress factors such as metal and radionuclide concentrations, salt, nitrate and nitrite concentrations, and other factors such as temperature and pH have a large effect on the proliferation of DvH biomass. By applying these stress factors in a controlled fashion, we can quantify their effects and the role they play in the growth response of DvH as compared to JW707 in various environments. Biolog in Hayward has developed the Omnilog Phenotype Microarray system for highly efficient phenotypic analysis of microorganism cultures. Biolog's Phenotypic Microarray (PM) plates are designed to screen ~2000 phenotypical characteristics at once, ranging from osmotic pressure response, to folate synthesis. The Biolog "MT" plates were also used for further analysis of particularly important stressors, such as NaCl and NaNO3 for determination of minimum inhibitory concentrations (MICs), and comparison with the PM plates. The PM data was successfully acquired and a portion was used for comparison to MIC data. The remaining bulk of PM data was passed along to VIMSS colaborators for further analysis. The determined MICs for the stressors applied to JW707 are as follows: NaCl, 175 mM; NaNO3, 60 mM; KCl, 275 mM; NaNO2, 1.6 mM. MIC data will also be used by VIMSS colleagues in the future.