Environmental Health Research
Human Exposure to PAHs and Metals: Since 2002 Dr. Richards’ lab has investigated the potential for toxicant exposure to people living in Chattanooga. This was initially facilitated by the first NIEHS grant awarded to UTC. That grant was used to investigate the potential for PAH and metal exposure and effects to Chattanoogans from Chattanooga Creek. Chattanooga Creek runs through the city of Chattanooga and is contaminated with legacy industrial pollution. Many people live around the creek and are potentially exposed to toxicants from Chattanooga Creek. Dr. Richards’ laboratory (in conjunction with Southern Illinois University) determined the types of compounds present and the potential for effects in humans. This work was facilitated by high pressure liquid chromatography (PAH quantitation) and atomic absorption spectroscopy (metal quantitation) and by measuring biomarkers of exposure in small mammals inhabiting the floodplains of Chattanooga Creek. These data were then used to estimate likelihood of exposure and effects through probabilistic risk assessments.
Low Birth Weight Correlations to Pollution Exposure: Hamilton County, TN has a relative high incidence of low birth weight (full-term infants with a birth weight below 2500 g). Dr. Richards has partnered with Ms. Colleen Mikelson (UTC BGE), Dr. Dave Adair (Regional Obstetrical Consultants), Dr. Peggy Kovach (UTC BGE), Dr. Richard Miller (University of Rochester Medical Center), Dr. Steve Symes (UTC Chemistry Department), and Dr. Jacopo Troisi (Università degli studi di Salerno, Italy), to investigate the potential for toxicants to influence 11BHSD2 expression and low birth weight in Hamilton County infants. To date >1000 placentae have been collected from Hamilton County mothers and quantified for concentrations of PAHs, PCBs, BPA, and numerous metals.
Ecological Effects of Pharmaceuticals in Surface Water: Human and veterinary pharmaceuticals are commonly found in the aquatic environment. Due to their physicochemical and biological properties, there is concern about the potential for their impacts on non-target species. Sewage treatment plants (STPs) are a major point source of these compounds. As a result, pharmaceuticals reach surface water and sediments, resulting in concentrations typically ranging from ng/L to μg/L. The natural aquatic environment has the potential to degrade pharmaceuticals by biotic and abiotic processes, but the continuous discharge of pharmaceutical-contaminated effluent on a daily basis results in pseudo-persistence. The potential long-term ecological significance of this continual discharge remains largely unknown. Students in Dr. Richards’ laboratory have investigated effects on aquatic invertebrates, vertebrates, and plants in an effort to better understand the risk to indigenous organisms.
Dr. Richards’ research has led to many relationships with local regulator, medical, civic, and government groups. Dr. Richards addresses local toxicological issues through his research and by serving on the Hamilton County Regional Health Council. He has given talks to the local community about ambient toxicant exposure and has forged relationships with hospital administration and physicians. These relationships have been very helpful to Dr. Richards’ lab for subject enrollment and sample collection. Internationally, the research in Dr. Richards’ laboratory has resulted in international peer-review journal publications, invitations to present at Beijing and Harbin Normal University, The Annual Meeting of the American College of Toxicology, Oak Ridge National Laboratory and numerous local meetings.
Grants/Projects Since 2009
$2,500,000 – National Children’s Study, Bradley County, TN (2013). D. Adair and C. Hall (PI), G. Heath (Co-PI), and S. Richards. Source: National Institutes of Health (awarded but rescinded when the National Children’s Study was dissolved).
$379,355 – Investigation of the Cause of Low Birthweight Infants in Hamilton County, TN. (2008-2012). Sean Richards (P.I.), D. Adair, S. Symes. Source: U.S. Department of Health and Human Services (DHHS/HRSA 1H1SMC10654-01-00 RICHARDS 08-).
Publications Since 2009
*denotes student author; 10 of 27 total publications are shown
C Mikelson*, MJ Kovach, J Troisi, S Symes D Adair, RK Miller, C Salafia, K Johnson, Z Lin., S. Richards. Placental 11β-Hydroxysteroid Dehydrogenase Type 2 Expression: Correlations with Birth Weight and Placental Metal Concentrations. (in press).
D Wolfe*, Schorr M, Hanson M, Nelson CH and Richards SM. 2015. Hazard assessment for a pharmaceutical mixture detected in the upper Tennessee River using Daphnia magna. Global Journal of Environmental Science Management 1(1): 1-14. ISSN 2383-3572.
J Troisi*, Mikelson C, Richards SM, Symes S, Adair D, Zullo F and Guida M. 2014. Placental concentrations of bisphenol A and birth weight from births in the Southeastern U.S. Placenta 35(11): 947-952.
Schorr MS, Dyson MC, Nelson CH, Van Horn GS, Collins DE, Richards SM. 2013. Effects of stream acidification on lotic salamander assemblages in a coal-mined watershed in the Cumberland Plateau. Journal of Freshwater Ecology Vol. 28, No. 3, 339-353.
E. Hussar*, S. Richards, ZQ Lin, R.P. Dixon , and K. A. Johnson. 2012. Human Health Risk Assessment of 16 Priority Polycyclic Aromatic Hydrocarbons in Soils of Chattanooga, Tennessee, USA. Water, Air, & Soil Pollution 22 (9):5535-5548.
S. Richards, D. Ford, and K. Adsit. 2012. Integrating Inquiry-Based Field Investigations into an Environmental Science Curriculum. Journal of Tennessee Academy of Sciences 87 (2):105-115.
R. Red*, S. Richards, C. Torres, C. Adair. 2011. Environmental Exposures and Pregnancy Emergencies. Obstetrical & Gynecological Survey 66 (3):159-69.
P. Tithof, S. Richards, Elgayyar MA, Menn FM, Vulava VM, McKay L, Sanseverino J, Sayler G, Tucker DE, Leslie CC, Lu KP, Ramos KS. 2010. Activation of group IVC phospholipase A(2) by polycyclic aromatic hydrocarbons induces apoptosis of human coronary artery endothelial cells. Archives of Toxicology. 2010 Dec 4.
J. Conley*, S. Symes, M. Schorr, M. Hanson, S. Richards. 2009. Is ambient chitobiase activity a monitoring tool for impacts on secondary productivity in lotic systems? Canadian Journal of Fisheries & Aquatic Sciences 66:1274-1281.
S. Moss*, J. Keller, S. Richards, T. Wilson. 2009. Levels of persistent organic pollutants in plasma from a riverine turtle assemblage from the Tennessee River Gorge. Chemosphere 76:194-204.
* denotes student author
J. Conley* and S. Richards. 2013.Environmental Teratogenesis. In (ed) J.F. Férard and C. Blaise, Encyclopdedia of Aquatic Ecotoxicology. Invited Submission. Publisher: Springer, New York, New York.
C. Mickelson* 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. Invited Submission. Publisher: Nova Publishing, Hauppauge, NY (pp 61-88).
J. Conley* and S. Richards. 2008. Ecotoxicology: Teratogenesis. In (ed) B. Ronan, Encyclopedia of Ecology. Invited Submission. Publisher: Elsevier, Oxford, UK. Pp 3528-3535.
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. Invited Submission In: (ed) J.J. Johnston, Pesticides and Wildlife. American Chemical Society, Clarendon Hills, IL.
Associate Editor for Ecological Risk Assessment: Ecotoxicology (2006-present).
Current Member of the US EPA Food Quality Protection Act (FQPA) Science Review Board (SRB) (2004- present).
Editorial Board: Global Journal of Environmental Science & Management (2014–present).