Philip N. Smith - Research

 


Current Research

 

Air Issues

Current large-scale beef production operations in the United States concentrate large numbers of cattle onto feedlots prior to slaughter. Beef cattle production is augmented by widespread use of anabolic growth promoters (hormones) which divert resources from reproductive development to formation of muscle mass. As a result, large quantities of potent anabolic steroids are excreted into the environment. By their very nature, hormones are biologically active at exceedingly low concentrations and influence growth, development, and reproduction in all vertebrates. Synthetic hormones are more resistant to microbial degradation and persist in the environment longer than natural hormones.  Run-off from confined animal feeding operations (CAFOs) is considered the primary route of transport. Serious developmental and reproductive effects have been documented among aquatic organisms in surface waters near CAFOs.  Our research will answer the questions, “Are anabolic hormones transported from feedlots by wind, and if so, are quantities sufficient to result in adverse effects?”

 

Water Issues

Water quality and availability are also critical issues in Texas and throughout the world.   Dr. Smith has recently become involved in efforts to integrate environmental research and educational programs focused on water and water quality.  For example, the critical water quality issues of Marion County, Texas and the greater Caddo Lake watershed are being addressed through a partnership with the Jeffersonian Institute in Jefferson, Texas.  This applied environmental research program provides extensive opportunities for the education of scientists, teachers, and citizens of the broader community that will result in a science-based understanding and appreciation of wetlands and their fauna.  Integrating research with educational programs for students provides the contextual basis for conservation of natural resources, long-term environmental biology research, and the development of environmentally conscientious and responsible scientists, teachers and citizens.  These efforts can be leveraged to facilitate rural economic development and improve quality of life.  In addition to examining water issues in East Texas, Dr. Smith is examining water issues in the Southern High Plains.  He and his students are interested in developing sentinels of ecological health for the unique playa lakes of West Texas.  Current work is focused on pesticide runoff and the effects of unregulated pesticide formulation ingredients on playa-dependent organisms.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Recent Research

A great deal of Dr. Smith’s research at TIEHH has focused on the ecological effects of compounds used for military-related purposes like perchlorate and HMX.  In its various salt formulations (i.e., sodium perchlorate, ammonium perchlorate, etc.), perchlorate is used as an oxidizer and makes up a high percentage of the total weight of various solid rocket formulations and can also be found in flairs, pyrotechnics, and even air-bags.  In the environment, perchlorate is an extremely water soluble anion that can persist for decades.  It is readily taken up by plants, and can alter thyroid hormone concentrations in exposed humans and wildlife.  HMX is an explosive formulation that is commonly found and military training sites across the country. 

 

 

Dr. Smith has been heavily involved in research related to perchlorate and explosives.  That work was funded by the Strategic Environmental Research and Development Program (SERDP), the United States Department of Agriculture (USDA), and others.  Much of the perchlorate research is included in a book entitled Perchlorate Ecotoxicology that Dr. Smith and Dr. Ron Kendall published with their colleagues in 2006.  Additionally, Dr. Smith has conducted research to examine the energetic costs of various anthropogenic and natural stressors in macroinvertebrates and aquatic vertebrates inhabiting playa lakes in the Southern Great Plains. 

 

Also of particular research interest to Dr. Smith is the role of persistent organic pollutants, other industrial chemicals, and pesticides in canine carcinogenesis.

 

Other projects are described below:

 

 2008   Effects of Perchlorate in Waters from NWIRP, McGregor on a Native Amphibian Species

Assessment of Airborne Anabolic Hormones from Confined Animal Feeding Operations

 

2007   Ecological Risk Assessment of Mercury in the Caddo Lake Watershed

Effects of PAHs on Avian Species, and HMX Exposure in a Hind-gut Fermenting Species, the Prairie vole

 

2006   Playa Wetland Environmental Stress Effects on Indigenous Fairy Shrimps

Bioavailability and Avoidance of HMX in a Terrestrial Amphibian

Evaluating Metabolic Induction and Reproductive Toxicity of TNT in Peromyscus maniculatus

 

2005   Bioavailability and Avoidance of HMX in a Terrestrial Amphibian

        Evaluating Metabolic Induction and Reproductive Toxicity of TNT in Peromyscus maniculatus

 

2004   Acute effects of the explosive compound HMX on avian and reptilian species

            Reproductive toxicity of HMX in birds and reptiles

 

2003   Effects of perchlorate on metabolic rates in endothermic organisms

            Effects of perchlorate on Wood Ducks (Aix sponsa)

            Immunotoxicological responses of amphibians exposed to perchlorate

Bosque and Leon River Watershed Study;  Terrestrial ecotoxicology of perchlorate in the Lake Waco and Lake Belton watershed

            Evaluating exposure and effects of perchlorate on mammalian (including cattle), avian, and reptilian wildlife species2002      Perchlorate exposure among wild rodents

           

2002   Perchlorate accumulation and toxicity from consumption of food crops grown with contaminated irrigation water

 

2001   Raccoons as a sentinel of environmental perchlorate contamination

Development and evaluation methods to accurately determine avian habitat use and habitat-specific behaviors in agricultural systems

 

1997   Raccoons (Procyon lotor) as sentinels for polychlorinated biphenyl and heavy metal exposure and effects at the Paducah Gaseous Diffusion Plant, McCracken County, KY     

 

1996   Rodents as biomonitors of PCB and metal contamination at the Paducah Gaseous Diffusion Plant, McCracken County, KY

 

 

I am grateful to have received funding from the following agencies: 

  • Ensafe, Inc.

  • State of Texas Advanced Research Program

  • Texas Tech University Research Enrichment Fund

  • Strategic Environmental Research and Development Program

  • Texas Tech University Research Enhancement Fund

  • US Corps of Engineers

  • Caddo Lake Institute

  • USDA Cooperative State Research, Education, and Extension Service National Research Initiative Competitive Grants Program

  • US Environmental Protection Agency

  • Bechtel Jacobs, Inc.

  • Martin Energy systems, Inc.       

 

 

 

 

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