Grantee Research Project Results
1999 Progress Report: Ecotoxicity Risks Associated with the Land Treatment of Petrochemical Wastes
EPA Grant Number: R826242Title: Ecotoxicity Risks Associated with the Land Treatment of Petrochemical Wastes
Investigators: Lochmiller, Robert L.
Current Investigators: Janz, David M.
Institution: Oklahoma State University
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1997 through September 30, 2000
Project Period Covered by this Report: October 1, 1998 through September 30, 1999
Project Amount: $406,229
RFA: Exploratory Research - Environmental Biology (1997) RFA Text | Recipients Lists
Research Category: Biology/Life Sciences , Aquatic Ecosystems
Objective:
Although many consider land treatment of petrochemical industrial wastes to be a viable and safe management practice, recent field studies by our laboratory raise serious environmental concerns regarding immunotoxicity and fluorosis risks to wild vertebrates. Our objective in this study was to examine these concerns by monitoring immunologic and pathologic responses of cotton rats (Sigmodon hispidus) in situ by seasonally collecting resident animals from replicated land treatment and reference sites throughout Oklahoma. Biomarker responses (immune system function, biotransformation enzyme activities, pathology) are being compared to soil and tissue contaminant levels to identify probable causative agents.Progress Summary:
We have just completed the second year of our research, with 1 year of funding remaining. We have nearly completed 2 complete years of demographic monitoring of 10 rodent assemblages (5 land treatment sites, 5 reference sites). The five land treatment study sites we selected for intensive monitoring were paired with an ecologically similar reference site nearby. Soil samples have been collected from each site in summer and winter, and samples have been analyzed for organic and inorganic contaminants. Monitoring demographic changes in the small mammal assemblages on each study site has consumed a considerable amount of our time in the field. A total of 20,480 trap-nights of activity have yielded a total of 2,741 unique captures of small mammals. Cotton rats have been the dominant species caught, with 1,949 unique individuals caught. Other species in the assemblage include Reithrodontomys fulvescens, Chaetodipus hispidus, Neotoma floridana, Peromyscus leucopus, P. maniculatus, Mus musculus, Microtus pinetorum, M. ochrogaster, Blarina brevicauda, and Oryzomys palustris. Trap data have been entered into a computer spreadsheet and analyzed with the program CAPTURE to determine population density on each study site.Twelve cotton rats (adults, 6 female, 6 male) were collected from each study population in winter and summer for assessing biomarker responses. Animals were returned to the laboratory for measuring biotransformation enzyme activity, immunocompetence (measures of innate immunity, B-cell function, in vivo cell-mediated immunity, macrophage function, hematology), pathology, and tissue metal analyses. A total of 240 animals were processed last year from these 10 study sites.
Our initial studies have confirmed our original predictions that land treatment of petrochemical wastes results in the accumulation of inorganic chemicals (metals and F), which do not biodegrade and accumulate in soil. Land treatment sites tend to be high in Pb, F, Zn, Cr, Cu, Sr, and Ti compared to reference soils. These accumulations in the soil appear to pose a risk to resident wildlife in these ecosystems. Our study has documented the existence of dental lesions in a high proportion of small mammals residing on land treatment study sites. Dental lesions are virtually nonexistent on reference sites. Bone fluoride analyses have demonstrated a strong relationship between bone accumulations of F and severity of dental lesions. The incidence of dental lesions appears to be related to life history of the small mammal species, with arboreal and seed-eating rodents being less susceptible to fluorosis than ground-dwelling herbivores and insectivores. Dental lesions are about 50 percent more prevalent in winter than summer in cotton rats. In addition to F, bone Pb levels appear to be 2- to 40-fold greater in cotton rats residing on land treatment sites compared to reference sites. Exposure to the complex mixtures of contaminants on these land treatment sites appears to increase the level of ovarian and thymic apoptosis (rate of programmed cell death) in cotton rats. Immune function assays have also revealed possible alterations in T-cell and macrophage function on some land treatment sites?data analyses are only preliminary, however. These physiological alterations observed above also appear to have an influence at the population and community level. Although all cotton rat populations show a numerical increase in late summer and a crash in winter, this trend appears to differ in amplitude between contaminated and reference populations. Preliminary analyses suggest that contaminated populations do not reach as high of numbers as reference populations in summer, and fall to incredibly low densities during the winter.
Future Activities:
Work during the final year of funding will be devoted to completing the last winter season of sampling, including monitoring demographic changes in the rodent assemblage on all 10 study sites, and the completion of laboratory assessments of collected cotton rats. We will use this last year to complete all laboratory work that remains. Histological and hematological slides must be read, enzyme activities completed, and tissue metal analyses must be completed in the laboratory. Extensive data analyses remain, and work in this area will consume the vast majority of the second half of next year. Several publications are planned for this year.Journal Articles on this Report : 2 Displayed | Download in RIS Format
Other project views: | All 12 publications | 12 publications in selected types | All 10 journal articles |
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Type | Citation | ||
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Lochmiller R.L., McMurry S.T., McBee K., Rafferty D.P., Lish J.W. and Qualls Jr C.W. Seasonal hepatic cytochrome P-450 induction in cotton rats (Sigmodon hispidus) inhabiting petrochemical waste sites. Environmental Pollution, Volume 105, Issue 2, May 1999, Pages 191-196. |
R826242 (1999) |
not available |
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Savabieasfahani M, Lochmiller RL, Janz DM. Elevated ovarian and thymic cell apoptosis in wild cotton rats inhabiting petrochemical-contaminated terrestrial ecosystems. Journal of Toxicology and Environmental Health-Part A 1999;57(8):521-527. |
R826242 (1999) R826242 (Final) |
not available |
Supplemental Keywords:
terrestrial, ecosystem, indicators, assessment, southcentral, land farm, petrochemical pollution, wildlife toxicology, ecotoxicity, oil refinery pollution, immunotoxicity, soil contaminants, zoology, heavy metals, PAHs., RFA, Scientific Discipline, Toxics, Waste, Ecosystem Protection/Environmental Exposure & Risk, National Recommended Water Quality, exploratory research environmental biology, Environmental Chemistry, Ecosystem/Assessment/Indicators, Chemical Mixtures - Environmental Exposure & Risk, Ecosystem Protection, chemical mixtures, Ecological Effects - Environmental Exposure & Risk, Ecological Effects - Human Health, Hazardous Waste, Biochemistry, Environmental Monitoring, Ecological Risk Assessment, Ecology and Ecosystems, Hazardous, Ecological Indicators, ecological exposure, adverse impacts, biomarkers, wildlife, dose-response, immunotoxicity, petrochemical wastes, lead, petrochemical waste, biomonitoring, ecological assessment, oil refinery pollution, oil spills, assessment methods, biotransformation, ecotoxicological studies, water quality, arsenicProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.