Superfund Research grantee honored by American Chemical Society
By Sara Mishamandani
Louisiana State University (LSU) chemist and Superfund Research Program (SRP) Center Director Barry Dellinger, Ph.D., has been awarded the 2014 American Chemical Society (ACS) Award for Creative Advances in Environmental Science and Technology, sponsored by the ACS Division of Environmental Chemistry and the ACS Publications journal Environmental Science and Technology. Dellinger will receive the honor for his pioneering research on the sources, origin, and environmental chemistry of combustion-generated polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF).
The award is based on nominations of fellow scientists and further vote from the ACS Nomination Committee, and is meant to encourage creativity in research and technology, to provide a scientific basis for informed environmental decision-making or to provide practical technologies that will reduce health risk factors. Dellinger will receive the award at a ceremony March 18, 2014, in conjunction with the 247th ACS National Meeting and Exposition in Dallas.
Understanding the mechanisms of toxic combustion byproducts
Dellinger’s research focuses on the environmental aspects of combustion. Although combustion and industrial thermal processes are essential to everyday life, they can produce a myriad of harmful pollutants. PCDD and PCDF are particularly toxic combustion byproducts, inducing tumors and birth defects in human populations.
“While the biomedical research community is hard at work understanding the health impacts of pollution, and the engineering community is developing methods for pollution control, surprisingly little is known about the mechanisms of formation of combustion-generated pollutants,” said Dellinger. “Our research places pollution prevention on a sound scientific basis, and provides a critical interface between engineering and biomedical research.”
Dellinger’s team is determining how chemicals adsorb on various surfaces and form dioxins, and is studying the role of transition metals in the formation of dioxins. As an outgrowth of this research, Dellinger is also actively engaged in the development of innovative catalysts for destruction of toxic chlorinated hydrocarbons formed in combustion processes when chlorine is present.
SRP work on environmentally persistent free radicals
The LSU SRP center focuses on newly identified pollutant-particle systems and environmentally persistent free radicals (EPFRs), which may form from the combination of pollutants and particulate matter.
EPFRs form in combustion and thermal processes, including hazardous waste incineration and diesel combustion. These processes create particulate matter (PM), tiny air pollution particles only detectable with an electron microscope. PM2.5, classified as fine PM, is 2.5-0.1 micrometers in diameter, which provides the perfect binding surface for EPFR formation. EPFR attachment to PM allows the EPFR to persist much longer than a typical free radical.
“In collaboration with the biomedical and engineering communities, we are working to determine the actual mechanism of biological activity, the source of these radicals, and their atmospheric chemistry,” said Dellinger.
Particles in the PM2.5 range can reach deep into the respiratory tract. Dellinger and his research group demonstrated that, when inhaled, EPFR on the PM2.5 scale generates reactive oxygen species (ROS) that result in DNA strand breakage. These breaks can result in development of various cancers and cardiovascular disease.
Dellinger’s team recently revealed the various ways EPFRs decay in the environment. In a study published in the journal Environmental Science and Technology, Dellinger also associated the amount of radical measured in PM2.5 to cigarette smoke, suggesting that inhaling air polluted by PM2.5 may equate to smoking 0.3-0.9 cigarettes a day in the United States, depending on residence. The cumulative effect of breathing this type of air pollution may negatively impact human health.
(Sara Mishamandani is a research and communication specialist for MDB Inc., a contractor for the NIEHS Superfund Research Program and Division of Extramural Research and Training.)