New Waves March 2009

Breaking news about water resources research and education in Texas

TWRI grant recipient studies the aquatic hazard of ionizable compounds

By Caitlin Churchill

Theodore Valenti, now earning his Ph.D. from Baylor University's Interdisciplinary Graduate Degree Program in Ecological, Earth, and Environmental Science, recently worked with his advising professor Dr. Bryan Brooks to determine how variability among water quality parameters of the Brazos River basin influence aquatic risk of ionizable compounds.

Valenti is a recipient of a 2007-08 Texas Water Resources Institute (TWRI) research grant. With the $5,000 research grant, Valenti first gathered historical and current water quality data for spatial comparison among the different regions of the 42,000 square mile Brazos River Basin. Valenti then determined if site-specific water quality criteria were affected by ionizable compounds, such as pharmaceutical and personal care products, pesticides, fertilizers, ammonia, and other chemicals associated with urban development.

His interest in studying how ionization states may influence risk assessment was triggered during a toxicology class.  "The distribution of drugs in the body is sometimes influenced by varying pH of different body components," he said. "This knowledge caused me to wonder whether differences in the pH of freshwater receiving systems may alter the behavior, and ultimately the risk posed to biota from exposure."

Valenti said what people put down the drain may very well make it into a river. "Sewage treatment facilities do an excellent job removing nutrients and pathogens, yet are not purposely designed to remove many organic contaminants.  Advances in analytical techniques have allowed researchers to detect trace levels of various man-made contaminants in the environment, such as pharmaceutical and pesticides." Though the presence of an ionizable compound may not result in risk, high concentrations may threaten human and ecosystem health, he said.

According to Valenti's final report, continued population growth and urbanization will likely increase the release of ionizable compounds into waterways. "It is important that best management approaches are developed at the watershed scale to decrease water quality degradation by ionizable compounds," he wrote in his report.

"A major accomplishment achieved with this research project was spurring interest from members of the scientific community," Valenti said. Besides preparing his project's results for publication, he has presented his findings at several scientific conferences, including the American Water Resource Association's 2007 summer conferences and the 2008 American Chemistry Meeting.

After Valenti completes his doctorate, he plans to remain active in research as a professor. "I hope to continue to research topics that will minimize and ameliorate damages to freshwater systems due to human activities," he said.

Research conducted by Valenti was funded by TWRI using monetary means obtained through the U.S. Geological Survey as part of the National Institutes for Water Research annual research program. TWRI is the designated institute for water resources research in Texas.

For more information on Valenti's research, visit the TWRI USGS Research Grants Web page.

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