At the 42nd International Symposium on Halogenated Persistent Organic Pollutants (DIOXIN2022), researchers from around the world gathered to share the latest findings on this particularly harmful class of pollutants. Each year, the international DIOXIN Symposium brings together scholars to present cutting-edge scientific research from a variety of disciplinary perspectives, with persistent halogenated organic pollutants as the unifying theme. This year’s conference, which was held in New Orleans on October 9–14, 2022, attracted 320 participants. Click here for an overview of the DIOXIN2022 program.

Persistent organic pollutants, sometimes referred to as “forever chemicals,” are highly toxic pollutants that are very slow to break down and thus remain in the environment for a long time. They are common worldwide and very hazardous to humans. Persistent organic pollutants, which include both intentionally and unintentionally produced chemicals, have been linked to a range of adverse health effects in people, including problems related to reproduction, development, and the immune and endocrine systems. Slawo Lomnicki, PhD, who leads the LSU SRP “Activation, Sensing, and Prevention of Formation of Environmentally Persistent Free Radicals (EPFRs) in Thermal Treatment of Superfund Wastes” project and is Professor of Environmental Sciences at LSU, served as DIOXIN2022 Chair. Commenting on the important topics covered at the conference, Dr. Lomnicki remarked,

"The scientific program covered prominent issues that have emerged in recent years. This included, to name a few examples, new aspects of persistent pollutants such as fluorinated compounds, micro- and nano-plastics, electronic wastes, and new classes of brominated flame retardants."

A total of 163 talks were presented across 32 regular sessions, with session topics including, among others, the fate and detection of specific toxins, global monitoring of these pollutants, methodological advances, remediation, and analyses of the risks posed by flame retardants. A session was also devoted to the policy implications of new scientific developments. An additional 73 posters were presented across three poster sessions, and the conference featured eight plenary presentations by top international scholars.

In addition to welcoming meeting participants as LSU SRP Director and Associate Vice President for STEM Research and Economic Development, Stephania Cormier, PhD, Wiener Chair and Professor of Biological Sciences at LSU, along with co-authors Liana Baconguis, LSU SRP trainee and graduate student in comparative biomedical sciences at the LSU School of Veterinary Medicine, and Arundhati Bakshi, PhD, from the Louisiana Department of Health, also presented a talk at the conference. This talk focused on Colfax, Louisiana, a community whose air quality is influenced by Clean Harbors, the only commercially operating open-burn/open-detonation hazardous waste thermal treatment facility in the United States. LSU SRP team members used data from the Louisiana Department of Health (2000–2017) to compare cardiovascular and respiratory disease hospitalizations for residents of Colfax, other areas in Grant Parish, and the state of Louisiana. Dr. Cormier summarized the findings as follows:

"Hospitalization rates were significantly higher for Colfax than for the rest of Grant Parish and the state of Louisiana for all cardiovascular disorders, ischemic heart diseases, hypertensive diseases, all respiratory disorders, and asthma. Mortality rates were significantly higher for Colfax than for the rest of Grant Parish and the state of Louisiana for all cardiovascular diseases, hypertension, and ischemia. Mortality rates were significantly higher than the rest of Grant Parish and the state of Louisiana for respiratory tract infection, and they were significantly higher than the state of Louisiana for lung cancer and chronic obstructive pulmonary disease."

In Colfax, these researchers also found higher hospitalization rates among African American residents than among White residents, which is not the case in surrounding regions. This work presents some of the first evidence of the human health effects of EPFRs.

Lavrent Khachatryan, PhD, LSU SRP Materials Core Leader and Research Assistant Professor in the Department of Chemistry at LSU, worked with co-authors Mohamad Barekati-Goudarzi, PhD; Rubik Asatryan, PhD, from the State University of New York at Buffalo; and Dorin Boldor, PhD, Professor in LSU’s Department of Biological and Agricultural Engineering, to present a talk examining the high-temperature decomposition of lignin, an organic polymer found in most plants, in the production of bio-oil. Dr. Khachatryan’s team is seeking to increase understanding of lignin chemistry and to improve the process by which natural lignin can be deconstructed to produce bio-oil and other value-added products. In the study presented here, they examined the production of polycyclic aromatic hydrocarbons, a common class of environmental pollutants, during this process.

Chuqi Guo, PhD, LSU SRP trainee and postdoctoral researcher, and Jennifer Richmond-Bryant, PhD, Leader of the LSU SRP “Hazardous Waste Thermal Treatment and Community Exposure to Environmentally Persistent Free Radicals” project and Associate Professor of the Practice in the Center for Geospatial Analytics at North Carolina State University, presented a poster on a community-centered approach to assessing exposure to toxic compounds among residents near a hazardous waste treatment facility, as well as the health-related outcomes associated with these exposures. Prakash Dangal, graduate student in environmental sciences at LSU, and Dr. Lomnicki also presented a poster on the development of a sensor to detect EPFRs in field settings.

LSU SRP trainees Prakash Dangal and Oluwafemi Awolesi (graduate students in LSU’s Department of Environmental Sciences); Divine Nde, PhD (postdoctoral researcher in LSU’s Department of Chemistry); and Farhana Hasan, PhD (postdoctoral researcher in LSU’s Department of Environmental Sciences) provided additional assistance with the conference organization.

Because of the COVID-19 pandemic, this was the first fully face-to-face DIOXIN meeting since 2019. Dr. Lomnicki commented on the importance of discussions and interactions at conferences for the advancement of research: “After a rocky two years, we were excited to have scientists from all around the world meet in person again and have vibrant discussions and interactions, without which progress in science is not possible.”