Events

Mix/RASS Webinar: Integrating Exposomics and Neuroimaging to Uncover Risk Factors and Neural Mechanisms of PTSD in 9/11 Responders

Hosted by: The SOT Risk Assessment and Mixtures Specialty Sections

After the 9/11 attacks, over 50,000 responders faced severe health challenges, including a high rate of persistent PTSD. The World Trade Center Health Program (WTCHP) helps monitor and treat these issues. Recent research indicates worsening physical and mental health among responders, linked to their WTC experiences.
To explore the risk factors, researchers used an exposomic approach to analyze various exposures and their impact on health outcomes like PTSD and respiratory issues. They also employed a new imaging method, the Anatomical Connectivity Fingerprint (ACF), to study brain changes in responders with PTSD compared to controls.
The study highlights the need to consider combined exposures and specific neural mechanisms in disaster response. These insights are crucial for developing targeted treatments and preventive measures for similar future events

Speakers:

• Megan K. Horton, PhD MPH, Professor, Icahn School of Medicine at Mount Sinai, Department of Environmental Medicine and Public Health
• Azzurra Invernizzi, PhD, Postdoctoral Fellow, Icahn School of Medicine at Mount Sinai, Department of Environmental Medicine and Public Health

Materials:

Webinar Recording and Materials

Jane Ellen Simmons Travel Award Finalist Competition

Hosted by: The SOT Mixtures Specialty Section

The Mixtures Specialty Section strongly believes that the future of mixtures research is dependent on today’s students, postdocs, and young investigators. This year, the MixSS has organized a webinar where students, postdocs, and young investigators will have the opportunity to present projects related to the mixtures field and compete for an award to support their travel to the 2024 SOT Annual Meeting in Salt Lake City. The travel award will be conferred in honor and remembrance of our dear colleague, Dr. Jane Ellen Simmons. Presentations will be approximately 10-15 minutes. The presentations and application package will then be judged by an expert panel, and a winner will be announced.

Presentations:
“Evaluation of Legacy and Replacement Per- and Polyfluoroalkyl Substances (PFAS) in Human Livers Banked Over the Past 20 Years”
Juliana Agudelo Areiza, PhD Candidate, University of Rhode Island

“PM2.5 Concentration, Composition, and Oxidative Potential in Jackson, MS”
Amelia Craze, Graduate Student (PhD), University of Mississippi

“Early Developmental Exposure to Liquid Crystal Monomer Mixtures Impacts Zebrafish Locomotive Behavior, Cellular Respiration, and Adiposity”
Samantha Heldman, PhD Candidate, Wayne State University

“Prenatal Exposure to Phthalates and Replacements in Association with Maternal Blood Pressure and Risk of Preeclampsia: Results from the Human Placenta and Phthalates Study”
Erin McNell, Predoctoral Fellow, National Institute of Environmental Health Sciences

“Evaluating the Sex-Specific Effects of a Persistent Organic Pollutant Mixtureon Metabolic Disruption in the Context of Adipose and Liver Endpoints”
Shikshita Singh, Undergraduate Student, University of Louisville

Mix/RASS Webinar: Advancing the Science of PFAS Mixtures Assessment

Hosted by: The SOT Risk Assessment and Mixtures Specialty Sections

Speaker:
Jason C. Lambert, PhD, Office of Research and Development, US EPA

An evolving landscape of per- and polyfluoroalkyl substances (PFAS) co-occur in environmental media such as water, however there are few studies or assessments of human health risks associated with exposure to mixtures of PFAS. The peer-reviewed literature to date suggests that mixtures of PFAS pose health risks greater than each substance on its own. As such, the US EPA’s Office of Water and Office of Research and Development has developed a draft “Framework for Estimating Noncancer Health Risks Associated with Mixtures of Per- and Polyfluoroalkyl Substances (PFAS).” This draft framework leverages existent US EPA component-based mixture assessment approaches, such as the hazard index, relative potency factors, and a mixture benchmark dose approach. The draft framework also advances approaches for the integration of new approach methodology (NAM)-based data for data-poor mixture component PFAS. This framework, once final, will provide US EPA partners and stakeholders with flexible approaches needed to evaluate potential health risks associated with exposure to mixtures of PFAS in environmental media.

Materials:
Webinar Recording
Presentation

Mixture Toxicity in the 21st Century: Assessment Methods Presentations

Hosted by: The SOT Risk Assessment and Mixtures Specialty Sections

Presentations:
Methodological Details for Quantifying the Risk of Exposure to Environmental Chemical Mixtures via a Common Molecular Target using a Geospatial Modeling Approach
Kristin Eccles, PhD, Healthy Environments and Consumer Safety Branch, Health Canada

Real-world chemical exposures are composed of multiple chemicals heterogeneously distributed across space. However, traditional risk assessments based on in vivo animal studies typically use a chemical-by-chemical approach and only consider apical disease endpoints. New approach methodologies (NAMs) in toxicology, such as in vitro high-throughput (HTS) assays generated in Tox21 and ToxCast, can quickly provide mechanistic chemical hazard information for chemicals without existing data. This talk will cover the methodological details for our recently published paper, where we integrated modeled county-level ambient exposures in the air from the USA-wide National Air Toxics Assessment (n = 41) with hazard data from curated HTS assays to identify regions where exposure to local chemical mixtures may perturb the same biological target.

The Hazard Index at Thirty-Seven
Paul S. Price, PhD, Risk Sciences International, Inc.

The Hazard Index (HI) was developed by the US EPA in 1986 as a quantitative tool for characterizing the safety of combined exposures to multiple chemicals. Thirty-seven years after the approach was developed, the HI, and related approaches, still dominate assessments of such exposures. Despite this dominance, the HI has significant limitations. This talk will review the technical concepts on which the HI is based and how the science behind the findings has changed over the last 37 years. The talk will also discuss how NAMS can provide both the data needed to assess larger numbers of chemicals and a basis for revising the HI to better address some of its limitations.

Materials:
Webinar Recording
Presentation—Kristin Eccles, PhD
Presentation—Paul S. Price, PhD

Mixture Assessment Factors—Motivations, Derivations and Uses

Jointly Sponsored Webinar with the Risk Assessment Specialty Section (RASS)

Speaker:
Andreas Kortenkamp, PhD, Brunel University London, Centre for Pollution Research and Policy

Mixture assessment factors have been proposed as a regulatory instrument for dealing with combined exposures to multiple chemicals. Their use is motivated by the realization that risks from combined exposures may arise even when each component in the mixture complies with its regulatory exposure limits. Since assessment factors in common use for the setting of single chemical exposure limits cannot accommodate mixture risks, an additional factor, the mixture assessment factor, is suggested to mitigate mixture risks.

This presentation will give a brief historical introduction to the genesis of the idea of a mixture assessment factor. Case studies from human toxicology and ecotoxicology will be used to illustrate the need for a mixture assessment factor. Various approaches for quantitative derivations of such factors will be presented and discussed. Finally, a summary of the policy context for implementing mixture assessment factors in the European Union will be given.

Materials:
Webinar Recording
Presentation

Combined Effects of Chemical Mixtures Are Predictable for the Whole Transcriptome—A Proof of Concept Toxicogenomic Study with Zebrafish Embryos

A Population-based Human In Vitro Approach to Quantify Inter-individual Variability in Responses to Chemical Mixtures

Jointly Sponsored Webinar with the Risk Assessment Specialty Section (RASS)

Materials:
Webinar Recording
Presentation—Wibke Busch, PhD
Presentation—Lucie Ford, Doctoral student

A Novel Framework to Form Sufficiently Similar Mixtures

Jointly Sponsored Webinar with the Risk Assessment Specialty Section (RASS)

Materials:
Webinar Recording
Presentation

The Missing Link: Ex Vivo E-Cigarette Toxicity Modeling

Jointly Sponsored Webinar with the Risk Assessment Specialty Section (RASS)

Materials:
Webinar Recording
Presentation

Characterization of Developmental Toxicity and Adverse Outcome Pathways (AOPs) for Emerging PFAS—Individual Compounds and Mixtures

Jointly Sponsored Webinar with the Risk Assessment Specialty Section (RASS)

Materials:
Webinar Recording
Presentation

Organizing Mechanism-related Information on Chemical Interactions Using a Framework Based on the Aggregate Exposure and Adverse Outcome Pathways

Materials:
Webinar Recording
Presentation

Rapid Hazard Identification of Environmental Chemicals and Mixtures

Materials:
Webinar Recording

A Novel Empirical Strategy Using Human Biomonitoring Data to Estimate Regulatory Guideline Values

Materials:
Webinar Recording
Presentation

EuroMix: An Assessment of Mixture Toxicity Using In Vitro Analyses of Liver Steatosis to Develop an Adverse Outcome Pathway Based Strategy

Materials:
Webinar Recording
Presentation

Use of Chemometrics and Multivariate Statistical Analysis to Determine Toxic Constituents Within Various Crude Oils

Temporal Trends of Cumulative Risks from Six Phthalates in Biomonitoring Data

Materials:
Webinar Recording
Presentation—Dr. Salley
Presentation—Dr. Reyes

Assessing the Health Impact of Diverse Mixtures in the Environment

Materials:
Webinar Recording
Presentation

Incorporating Non-Chemical Stressors into Cumulative Risk Assessment (CRA)

Materials:
Webinar Recording
Presentation

Highly Fluorinated Chemicals: A Legal and Technical Challenge

The Extensive Toxicology Data Behind Alternative Short-Chain Fluorinated Product Technology

Materials:
Webinar Recording
Presentation—Dr. Posner
Presentation—Dr. Buck

CHAMACOS: Lessons from the Fields

Materials:
Webinar Recording
Presentation

Toxicology for Breast Cancer Prevention

Materials:
Webinar Recording
Presentation

Interface of Health Effects Caused by the CardioMetabolic Syndrome and Exposures to Air Pollutant Mixtures

Materials:
Webinar Recording
Presentation

Risk from Multiple Chemicals in Polluted Communities

Materials:
Webinar Recording
Presentation

The Maximum Cumulative Ratio (MCR): A Tool That Uses Both Exposure and Toxicity Data to Determine When Cumulative Assessments Are Most Necessary

Materials:
Webinar Recording
Presentation

NoMiracle: Novel Methods for Integrated Risk Assessment of Cumulative Stressors in Europe

Materials:
Time-lapse Graph
Presentation