P. Lee Ferguson, Ph.D., from Duke University, develops sophisticated methods to answer important questions like, What chemicals are in your drinking water? What about inside your home?
Ferguson is a faculty member in the Pratt School of Engineering and the Nicholas School of the Environment at Duke. (Photo courtesy of Steve McCaw)Both environments typically contain thousands of compounds, including pollutants. Ferguson, an associate professor of civil and environmental engineering, described his work July 10 as part of the NIEHS Keystone Science Lecture Seminar Series.
Ferguson hopes his research will help inform people as they make choices about the products that they buy and wear. “What are the potential chemical exposures associated with the things we use on a daily basis?” he asked.
Using a variety of advanced biomedical analysis technologies, Ferguson brings a new approach to environmental analytical chemistry. For example, a technique called ultra–high-resolution mass spectrometry helps him determine the chemical content of samples taken from real-world environments, such as downstream of wastewater treatment plants.
The extremely complex mixtures may contain thousands of individual compounds. His approach also allows analysis of emerging contaminants, helping to keep watch on the health of ecosystems.
It was a packed house as Ferguson explained his cutting-edge methods to the NIEHS audience. (Photo courtesy of Steve McCaw)River runoff
Recent analyses by the Ferguson lab of water samples taken from the Catawba, Haw, and Neuse rivers in North Carolina showed distinct chemical signatures that reflected differences in their watersheds. For example, samples from the Neuse River reflected its path through a largely agricultural ecosystem, with trace contaminants from herbicides and fungicides.
Water downstream of more urbanized areas contained chemicals identified as additives in tire manufacturing. These compounds are a mark of stormwater runoff from roads.
Analysis of treated drinking water from the Catawba River identified byproducts of the disinfection process in water treatment. The high-tech analyses revealed other compounds such as sucralose, which is in the sweetener Splenda, pharmaceutical products, and even the chemical that makes toilet bowl water blue.
Dust detective
Ferguson has analyzed house dust samples to look at the indoor environment and found expected compounds such as phthalates and flame retardants.
Heather Henry, Ph.D., from the Superfund Research Program, introduced Ferguson. (Photo courtesy of Steve McCaw)He and his team were surprised to discover trace amounts of a class of dyes called azobenzenes. Ferguson said the commercial dyes, which are used to color textiles, are known to be mutagenic. According to Ferguson, they may also trigger allergies and asthma. He suggested that because they do not bind well to synthetic fabrics, they might rub off of the fibers and accumulate in dust.
Chemical code
Ferguson’s passion for the aquatic environment led him first to oceanography. In graduate school, he said, he started to become aware of the chemicals that end up in our waste streams. And then he discovered the promise of mass spectroscopy.
Ferguson said that being a mass spectrometrist is like having the cheat codes to the physical world we live in. “We’re able to see down underneath things that we use and that we interact with in our daily lives,” he said.
“I have made a career out of trying to use these technologies to understand more about the chemical exposures that we and our ecological environment are exposed to,” he added. “I get really passionate about the interface between the detection and analytical technologies and the health of our systems, our bodies, and our waters.”
(Ernie Hood is a contract writer for the NIEHS Office of Communications and Public Liaison.)
