Environmental Exposure and Effects of Pollutants
Sean Richards, Ph.D.
Research being conducted in my laboratory is focusing on the effects of pharmaceuticals on various aquatic organisms. This is an emerging issue in the environment. As the human population increases, so does the amount of direct and indirect consumption and excretion of pharmaceuticals, both in veterinary and medical application. The effects of this continual loading in the aquatic community are unknown. The goal of my laboratory is to determine the compounds that may be the most harmful to aquatic organisms so that actions may be taken to protect the environment, if necessary.
Another research focus is that of Chattanooga Creek, which runs through the city of Chattanooga. This surface water was used as a dumping ground for many of the industries in the Alton Park region of Chattanooga. Many people live a round the creek and are exposed to toxicants from the Chattanooga Creek. My laboratory is examining the types of compounds present and the potential for effects in humans. I am determining this via High Pressure Liquid Chromatography and by measuring biomarkers of exposure in small mammals inhabiting the floodplains of Chattanooga Creek. These data are then used to estimate likelihood of exposure and effects through probabilistic risk assessments.
My most recent endeavor is to research the causes of the extremely low birth weight of Hamilton County, TN infants. Due to unknown factors, Hamilton County produces some of the lowest birthweight infants in the United States. I have been working in conjunction with physicians and scientists from Columbia University, University of Rochester, University of Michigan, Erlanger Hospital, and Southern Illinois University to determine the cause of this effect. To facilitate this, we have collected >1000 human placentas from Hamilton County residents and analyzed them for arsenic. We have found that arsenic concentrations in these placentas are well above global averages (including developing countries such as Argentina and Bulgaria). We have also found that these arsenic concentrations are correlated with birthweight in Hamilton County. Research is ongoing and will include a suite of other toxicants including: PCBs, PAHs, lead, mercury, cadmium, and manganese.
Recent Grants and Projects
$ 383,000 – Investigation of the Cause of Low Birthweight Infants in Hamilton County, TN. (2008-2010). Sean Richards (P.I.), D. Adair, S. Symes. Source: U.S. Department of Health and Human Services.
$251,270 - Acquisition of a LC-MS-MS for Research in Biology, Environmental Science, and Chemistry at UT Chattanooga (2005). Sean Richards (P.I.), S. Symes, G. Grant, M. Kovach, D. Kreiss . Source National Science Foundation.
$178,953 – PAH/Metal Exposure and Effects Assessment in Chattanooga (2004-2007).
S. Richards (P.I.), M. Kovach, K. Johnson, Z. Lin. Source: National Institute of Health.
$95,100 - Acquisition of a Fluorescence Imaging System for Research in Biology, Environmental Science and Chemistry at UT Chattanooga. Major Research Instrumentation (MRI) grant (2003). M. Kovach (P.I.), S. Richards, M. Santiago, H. Spratt. Source: National Science Foundation
$131,642 – Integrated Inquiry-Based Field Investigations in Environmental Science
(2002-2004). S. Richards (P.I.), K. Adsit, D. Ford. Source: National Science Foundation
(with matching funds from UTC)
*denotes student author
Red, R., S. Richards, C. Torres, C. Adair. 2011. Environmental Exposures and Pregnancy Emergencies. Obstetrical and Gynecological Survey 66(3): 159-169.
*Moss, S., J. Keller, S. Richards, T. Wilson. 2009. Concentrations of persistent organic pollutants in plasma from a riverine turtle assemblage from the Tennessee River Gorge. Chemosphere 76(2):194-204.
J. Conley*, S. Symes, S. Kindelburger*, S. Richards. 2008. Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry Method For The Determination Of A Broad Mixture Of Pharmaceuticals In Surface Water. 2008. Journal of Chromatography A. In Press.
S. Richards, K. Eckert, J. Stephens, T. Rainwater. 2008. Idiosyncratic Procyon lotor behavior associated with canine distemper virus. Southeastern Naturalist. In Press
S. Richards, S. Kelly*, and M. Hanson. 2008. Zooplankton chitobiase activity as an endpoint of pharmaceutical effect. Archives of Environmental Contamination and Toxicology, 54:637–644.
S. Richards and S. Cole*. 2006. Developmental Toxicity of Thirteen Pharmaceuticals to Xenopus Laevis. Ecotoxicology, 15:647-656.
S. Richards, D. Ford, and K. Adsit. 2008. Integrating Inquiry-Based Field Investigations into an Environmental Science Curriculum. The Journal of Environmental Education. In press.
J. Conley*, S. Symes, S. Kindelburger*, S. Richards. Quantitation of Pharmaceutical in the Tennessee River Surface Water. Chemosphere. In press.
D. Adair, Z.Lin, S. Richards, C. Salafia, R. Miller, D. Misra, B. Duthie, and L. Mason, Human Placental Arsenic Levels Correlate with Low Birth Weigh (LBW). Journal of the Society for Gynecologic Investigation. 13 (2):198A 2006.
R. Miller, D. Wilson, C. Salafia, A Ornoy, S. Yacobi, S. Richards, et al. 2006. Environmental impact on placental function in diseases of pregnancy. Placenta, (9-10): A6.
C. Salafia, D. Adair, R. Miller, D. Misra, S. Richards, L. Mason, and A. Charles. 2006.Reduced chorionic vascular "fit" is correlated with shortened gestation, and reduced observed/expected birth weight ratio. Journal of the Society for Gynecologic Investigation. 13 (2):90A.
R. Brain*, D. Johnson*, S. Richards, M. Hanson, H. Sanderson, P. Sibley, K. Solomon. 2004. Effects of 25 Pharmaceutical Compounds to Lemna gibba Using a Seven-Day Static-Renewal Test. Environmental Toxicology and Chemistry. 23:371-382.
S. Richards, C. Wilson*, D. Johnson*, D. Castle, S. Mabury, S. Lam*, P. Sibley, and K. Solomon. 2004 Effects of Pharmaceuticals on Aquatic Ecosystems. Environmental Toxicology and Chemistry. 23:1035-1042.
M. Lam, C. Young, R. Brain, D. Johnson, M. Hanson, C. Wilson, S. Richards, K. Solomon, S. Mabury. 2004. The aquatic persistence of eight pharmaceuticals in outdoor microcosms monitored by HPLC-UV and LC-MS-MS using electrospray ionization. Environmental Toxicology and Chemistry. 23: 1431-1440.
R. Brain*, D. Johnson*, S. Richards, M. Hanson, H. Sanderson, P. Sibley, K. Solomon. 2004. Microcosm Evaluation of the Effects of an Eight Pharmaceutical Mixture to the Macrophytes Lemna gibba and Myriophyllum sibiricum exposed in Aquatic Microcosms. Aquatic Toxicology 70:23-40.
B. Brooks, C. Foran, S. Richards, J. Weston, P. Turner, J. Stanley, K. Solomon, M. Slattery, and T. La Point. 2003. Aquatic Ecotoxicology of Fluoxetine. Toxicology Letters. 142:169-183.
S. Richards, and R. Kendall. 2003. Physical Effects of Chlorpyrifos on Two Developmental Stages of Xenopus Laevis. Journal of Toxicology and Environmental Health 66: 75-91.
S. Richards and R. Kendall. 2002. Behavioral Effects of Chlorpyrifos on Two Developmental Stages of Xenopus Laevis. Environmental Toxicology and Chemistry 21: 1826-1835.
S. Richards, J. Gandy, J. Mattice, and T. Lavy. 2001. Airborne Concentrations of Propanil Within Residences of Families Living Adjacent to Aerially Sprayed Rice Fields. Archives of Environmental Contamination and Toxicology 41:112-116.
S. Richards, T. Anderson, M. Hooper, S. McMurry, S. Wall, H. Awata, M. Mayes and R. Kendall. 2000. European Starling (Sturnus vulgaris) Response to Chlorpyrifos Exposure in a Corn Agroecosystem. Toxicological and Environmental Chemistry 75: 215-234.
Books and Book Chapters
Mickelson, C.* and S. Richards. 2011. Zoonotic and Animal Vector Mediated Encephalitides. In (ed.) Sergey Tkachev, Non-flavivirus Encephalitis. Invited Submission. Publisher: InTech, Rijeka, Croatia. ISBN 979-953-307-178-6.
J. Leet* and S. Richards. 2009. Genetic Ecotoxicology. In (ed) F. Columbus, Ecotoxicology Research Developments. Publisher: Nova Publishing, Hauppauge, NY (In Press).
J. Conley* and S. Richards. 2008. Ecotoxicology: Teratogenesis. In (ed) B. Ronan, Encyclopedia of Ecology. Publisher: Elsevier, Oxford, UK.
B. Brooks, C. Foran, S. Richards, J. Weston, R. Brain, P. Turner, J. Stanley, K. Solomon, M. Slattery, and T. La Point. 2005. Aquatic Ecotoxicology of Fluoxetine: A review of recent research. In: Hot spot pollutants; Pharmaceuticals in the Environment. Publisher: John Hopkins University; Department of Pharmacology, Baltimore, Maryland, U.S.A.
Solomon KR, Brock TCM, de Zwart D, Dyer SD, Posthuma L, Richards SM, Sanderson H, Sibley PK, Van den Brink PJ (Editors). 2008. Pensacola, FL, USA: SETAC Press. 380pp.
Solomon KR, Brock TCM, de Zwart D, Dyer SD, Posthuma L, Richards SM, Sanderson H, Sibley PK, Van den Brink PJ. 2008. Chapter 1: Extrapolation in the Context of Criteria Setting and Risk Assessment. In: Solomon KR, Brock TCM, de Zwart D, Dyer SD, Posthuma L, Richards SM, Sanderson H, Sibley PK, Van den Brink PJ, eds. EXPECT: Extrapolation Practice for Ecotoxicological Effect Characterization of Chemicals. Pensacola, FL, USA: SETAC Press. 380pp.
Posthuma L, Richards SM, de Zwart D, Dyer SD, Sibley PK, Hickey C, Altenberger R. 2008. Chapter 5: Mixture Extrapolation Approaches. In: Solomon KR, Brock TCM, de Zwart D, Dyer SD, Posthuma L, Richards SM, Sanderson H, Sibley PK, Van den Brink PJ, eds. EXPECT: Extrapolation Practice for Ecotoxicological Effect Characterization of Chemicals. Pensacola, FL, USA: SETAC Press. 380pp.
Solomon KR, Brock TCM, de Zwart D, Dyer SD, Posthuma L, Richards SM, Sanderson H, Sibley PK, Van den Brink PJ. 2008. Chapter 8: Conclusions. In: Solomon KR, Brock TCM, de Zwart D, Dyer SD, Posthuma L, Richards SM, Sanderson H, Sibley PK, Van den Brink PJ, eds. EXPECT: Extrapolation Practice for Ecotoxicological Effect Characterization of Chemicals. Pensacola, FL, USA: SETAC Press. 380pp.
S. Richards, T. Anderson, S. Wall, and R. Kendall. 2000. Exposure Assessment of Rana Catesbeiana Collected from a Chlorpyrifos Treated Cornfield. In: (ed) J.J. Johnston, Pesticides and Wildlife. American Chemical Society, Clarendon Hills, IL.