Superfund Research Program
Environmentally Persistent Free Radicals
Center Director: Stephania A. Cormier
Grant Number: P42ES013648
Funding Period: 2009-2018 and 2020-2024
Nearly 53 million people (17 percent of the U.S. population; 18 percent of children < 5 years old) live within three miles of a Superfund remediation site. Superfund sites contain a wide variety of pollutants, including organic chemicals, metals, carbonaceous material, and silica. Although each of these components is capable of damage to organisms, their potential to combine into unique hazardous agents has been understudied. Interestingly, when these agents are present together, particularly during thermal remediation, they combine to form particulate matter (PM) with chemisorbed free radicals that persist in the environment and yet are biologically active. These pollutant-particle systems are called environmentally persistent free radicals (EPFRs). EPFRs are produced during thermal treatment of hazardous wastes, and nearly 30 percent of all Superfund sites (excluding groundwater) are remediated by thermal treatment. EPFR concentrations near Superfund sites range from 1x10^18 - 4x10^19 EPFRs/g (spins/g) of PM. This suggests that a vast number of U.S. residents are exposed to PM containing EPFRs. Louisiana State University (LSU) Superfund Research Center researchers have shown that these EPFRs (1) induce cardiac and pulmonary dysfunction in the exposed host; (2) are associated with current wheeze in children, if present in household dust; and (3) are intermediates in the formation of new pollutants such as dioxins. The Center now seeks to understand how EPFRs induce pulmonary/cardiovascular dysfunction and how to attenuate EPFR formation, facilitate EPFR decay, and limit exposure to EPFRs, with the goal of improving human health and the environment. The researchers are determining how EPFRs are formed, stabilized, and decay and how they catalytically cycle to produce hydroxyl radicals. They are doing this using a suite of advanced surface and chemical analyses. Since the airway is a major site of entry of environmental PM, the researchers demonstrating a link between EPFR exposure and poor respiratory health in children using established community-based birth cohorts. They are exploring mechanisms of EPFR-induced asthma and cardiovascular disease using mouse models exposed by inhalation. Support cores (Administration, Data Management & Analysis, Community Engagement, Research Experience and Training Coordination, Materials, and Inhalation Toxicology) are providing essential, centralized reagents/services and technological resources, allowing for precision of data and economy of effort, and fostering interdisciplinary activities. To ensure success, experts in these respective fields were brought together as an External Advisory Committee to advise this Center. The chemistry and physics of EPFRs, let alone their health impacts, are poorly understood, and an interdisciplinary approach is required to address the critical research areas.