Grantee Research Project Results

Final Report: Cumulative and Integrative Biochemical Indicators

EPA Grant Number: R825433C046
Subproject: this is subproject number 046 , established and managed by the Center Director under grant R825433
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: UC Davis Center for Children's Environmental Health and Disease Prevention
Center Director: Van de Water, Judith
Title: Cumulative and Integrative Biochemical Indicators
Investigators: Higashi, Richard M. , Fan, Teresa W-M.
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: October 1, 1996 through September 30, 2000
RFA: Exploratory Environmental Research Centers (1992) RFA Text |  Recipients Lists
Research Category: Center for Ecological Health Research , Targeted Research

Objective:

The objective of this research project was to develop analytical biomarker techniques that are very rich in information, yet require a minimum of sample preparation. The techniques are utilized for stress biomarker analysis and, through humic material analysis, aid us in understanding metal bioavailability and the biochemical history of a site.

Summary/Accomplishments (Outputs/Outcomes):

This research project has the guiding philosophy of developing biomarker analytical techniques that are very rich in information, yet require a minimum of sample preparation. This requires the simultaneous development of new biomarkers as well as techniques to detect them. Much of the activities of this approach are described in detail in R825433C007 (Higashi, Environmental Chemistry of Bioavailability in Sediments and Water Column) and R825433C023 (Fan, Biomarkers of Ozone Damage to Sierra Nevada Vegetation), and will only be summarized here.

In Project R825433C007 for soils and sediments, the humic chemistry and extracellular biochemistry of lowest trophic-level organisms is considered by many to be an important entry point of metals into the ecotoxic food chain. We used multidimensional nuclear magnetic resonance (NMR) to obtain a "total organic profile" of the system (including unknown and unexpected compounds) as well as to probe chemical association mechanisms among organic chelators. Our article describing an approach to both comprehensive (broad) and detailed (depth) analysis of such ligands has just been published in the journal Phytochemistry. We also developed a pyrolysis-gas chromatography mass spectrometry (GCMS) technique that can analyze samples for humic structures, which can be repositories for the historical biochemistry of the site. This approach is anchored with other analytical techniques such as NMR, Fourier Transform Infrared (FTIR), and Energy-Dispersive X-ray fluorescence to greatly extend its interpretability. A manuscript describing humic surface properties, utilizing all of these techniques and others, has been published in Environmental Science and Technology.

In Project R825433C023, pyrolysis-GCMS again was employed to obtain detailed structural data on wood. Wood is a very information-rich substrate in which we have already found two new stress biomarkers, but more important, we can use it to obtain historical-scale trends of air pollution effects. We have now completed the study in 10 Sierra Nevada Range sites, in conjunction with the California Air Resources Board. The summary of our findings is included in the report for Project R825433C023.

The following activities were accomplished:

• Using pyrolysis-GCMS and two-dimensional (2-D) NMR (NOESY), we uncovered kinetic and structural interactions of certain biogenic ligands, Cd²⁺, and soil humic substance (HS) chemical structures that limit the formation of such Cd-immobilizing complexes. We showed that this type of ternary interaction might affect the bioavailability of metal ions to plants. This finding is significant because such complexity of interaction is typically assumed not to occur and changes how we design future studies to understand soil binding of toxic metals.

• Using a combination of a new HS isolation method with several 2-D NMR techniques and pyrolysis-GCMS, we found peptidic side groups to have a mobile nature, but lignin moieties were relatively rigid. This means that the peptidic moieties may be more accessible to water-borne contaminants than the lignin-derived parts of HSs. The development of the combination of these methods illustrates a path to mapping the highly complex HSs in terms of metal bioavailability. The level of detail of this information will change how we design future studies to understand soil binding of toxic metals.

• Under Cd treatment—with or without HSs—phytosiderophores and other exuded metal ion ligands (MIL) were suppressed, yet the uptake of transition metals Fe, Ni, Cu, Zn, and Mn were enhanced. Thus, we showed that the uptake of contaminant metals is linked with the uptake of nutrient metals. This information has implications for determining the mechanisms of contaminant uptake in various organisms. Other investigators may use this finding to refine their own research efforts.

• HS interactions with plant metal uptake showed that HSs did not attenuate—and even slightly increased—the accumulation of some transition metals and Cd in roots. HSs also stimulated plant growth, improved MIL production, and alleviated part of the Cd-induced growth inhibition. Thus, we showed that HSs can play multiple roles in toxic metal bioavailability as well as effects. Again, this finding improves the “roadmap” for further studies of how soils bind toxic metals.

• We conducted a proof-of-concept study and found that historical-scale monitoring of trees for ozone biochemical effects on forests may be feasible. This approach may give us important historical-scale information about air pollution effects on trees, so that we can draw conclusions about the effects of air pollution on the environment over time.

• We conducted a comprehensive follow-up study showing that most of the tree-ring biochemical markers were likely to be biomarkers of bioeffects resulting from photochemical oxidants. This information allows other investigators and us to make inferences about the effects of photochemical oxidants on forests over time.

• Because some tree-ring biochemical markers appeared to respond to oxidant exposure, trees potentially may be used as very long-term ozone level monitors. This finding potentially may give investigators a new way of monitoring ozone levels in the environment.

Supplemental Keywords:

ecosystem, ecosystem protection, environmental exposure and risk, geographic area, international cooperation, water, terrestrial ecosystems, aquatic ecosystem, aquatic ecosystem restoration, aquatic ecosystems and estuarine research, biochemistry, ecological effects, ecological indicators, ecological monitoring, ecology and ecosystems, environmental chemistry, restoration, state, water and watershed, watershed, watershed development, watershed land use, watershed management, watershed modeling, watershed restoration, watershed sustainability, agricultural watershed, exploratory research environmental biology, California, CA, Clear Lake, Lake Tahoe, anthropogenic effects, aquatic habitat, biogeochemical cycling, ecological assessment, ecology assessment models, ecosystem monitoring, ecosystem response, ecosystem stress, environmental stress, environmental stress indicators, fish habitat, hydrologic modeling, hydrology, integrated watershed model, lake ecosystems, lakes, land use, nutrient dynamics, nutrient flux, water management options, water quality, wetlands., RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Ecological Indicators, Ecological Risk Assessment, Ecosystem Protection, Chemistry, Forestry, Ecology, Biology, Ecosystem/Assessment/Indicators, exploratory research environmental biology, Ecological Effects - Environmental Exposure & Risk, Biochemistry, Ecology and Ecosystems, pine trees, bioindicator, natural-growth pines, biochemical indicators, biochemical measurements

Relevant Websites:

http://ice.ucdavis.edu/cehr/ Exit

Progress and Final Reports:

Original Abstract

1997

1998

1999 Progress Report

Main Center Abstract and Reports:

R825433    UC Davis Center for Children's Environmental Health and Disease Prevention

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R825433C001 Potential for Long-Term Degradation of Wetland Water Quality Due to Natural Discharge of Polluted Groundwater
R825433C002 Sacramento River Watershed
R825433C003 Endocrine Disruption in Fish and Birds
R825433C004 Biomarkers of Exposure and Deleterious Effect: A Laboratory and Field Investigation
R825433C005 Fish Developmental Toxicity/Recruitment
R825433C006 Resolving Multiple Stressors by Biochemical Indicator Patterns and their Linkages to Adverse Effects on Benthic Invertebrate Patterns
R825433C007 Environmental Chemistry of Bioavailability in Sediments and Water Column
R825433C008 Reproduction of Birds and mammals in a terrestrial-aquatic interface
R825433C009 Modeling Ecosystems Under Combined Stress
R825433C010 Mercury Uptake by Fish
R825433C011 Clear Lake Watershed
R825433C012 The Role of Fishes as Transporters of Mercury
R825433C013 Wetlands Restoration
R825433C014 Wildlife Bioaccumulation and Effects
R825433C015 Microbiology of Mercury Methylation in Sediments
R825433C016 Hg and Fe Biogeochemistry
R825433C017 Water Motions and Material Transport
R825433C018 Economic Impacts of Multiple Stresses
R825433C019 The History of Anthropogenic Effects
R825433C020 Wetland Restoration
R825433C021 Sierra Nevada Watershed Project
R825433C022 Regional Transport of Air Pollutants and Exposure of Sierra Nevada Forests to Ozone
R825433C023 Biomarkers of Ozone Damage to Sierra Nevada Vegetation
R825433C024 Effects of Air Pollution on Water Quality: Emission of MTBE and Other Pollutants From Motorized Watercraft
R825433C025 Regional Movement of Toxics
R825433C026 Effect of Photochemical Reactions in Fog Drops and Aerosol Particles on the Fate of Atmospheric Chemicals in the Central Valley
R825433C027 Source Load Modeling for Sediment in Mountainous Watersheds
R825433C028 Stress of Increased Sediment Loading on Lake and Stream Function
R825433C029 Watershed Response to Natural and Anthropogenic Stress: Lake Tahoe Nutrient Budget
R825433C030 Mercury Distribution and Cycling in Sierra Nevada Waterbodies
R825433C031 Pre-contact Forest Structure
R825433C032 Identification and distribution of pest complexes in relation to late seral/old growth forest structure in the Lake Tahoe watershed
R825433C033 Subalpine Marsh Plant Communities as Early Indicators of Ecosystem Stress
R825433C034 Regional Hydrogeology and Contaminant Transport in a Sierra Nevada Ecosystem
R825433C035 Border Rivers Watershed
R825433C036 Toxicity Studies
R825433C037 Watershed Assessment
R825433C038 Microbiological Processes in Sediments
R825433C039 Analytical and Biomarkers Core
R825433C040 Organic Analysis
R825433C041 Inorganic Analysis
R825433C042 Immunoassay and Serum Markers
R825433C043 Sensitive Biomarkers to Detect Biochemical Changes Indicating Multiple Stresses Including Chemically Induced Stresses
R825433C044 Molecular, Cellular and Animal Biomarkers of Exposure and Effect
R825433C045 Microbial Community Assays
R825433C046 Cumulative and Integrative Biochemical Indicators
R825433C047 Mercury and Iron Biogeochemistry
R825433C048 Transport and Fate Core
R825433C049 Role of Hydrogeologic Processes in Alpine Ecosystem Health
R825433C050 Regional Hydrologic Modeling With Emphasis on Watershed-Scale Environmental Stresses
R825433C051 Development of Pollutant Fate and Transport Models for Use in Terrestrial Ecosystem Exposure Assessment
R825433C052 Pesticide Transport in Subsurface and Surface Water Systems
R825433C053 Currents in Clear Lake
R825433C054 Data Integration and Decision Support Core
R825433C055 Spatial Patterns and Biodiversity
R825433C056 Modeling Transport in Aquatic Systems
R825433C057 Spatial and Temporal Trends in Water Quality
R825433C058 Time Series Analysis and Modeling Ecological Risk
R825433C059 WWW/Outreach
R825433C060 Economic Effects of Multiple Stresses
R825433C061 Effects of Nutrients on Algal Growth
R825433C062 Nutrient Loading
R825433C063 Subalpine Wetlands as Early Indicators of Ecosystem Stress
R825433C064 Chlorinated Hydrocarbons
R825433C065 Sierra Ozone Studies
R825433C066 Assessment of Multiple Stresses on Soil Microbial Communities
R825433C067 Terrestrial - Agriculture
R825433C069 Molecular Epidemiology Core
R825433C070 Serum Markers of Environmental Stress
R825433C071 Development of Sensitive Biomarkers Based on Chemically Induced Changes in Expressions of Oncogenes
R825433C072 Molecular Monitoring of Microbial Populations
R825433C073 Aquatic - Rivers and Estuaries
R825433C074 Border Rivers - Toxicity Studies