Many of the webinars hosted by SOT Regional Chapters, Special Interest Groups, and Specialty Sections—collectively known as the SOT Component Groups—are recorded and posted exclusively for member access only in ToXchange. Select videos also are made available to the public through the SOT Video Library. In this blog, you will find a listing of all the recent webinar recordings that have been added to ToXchange and/or the SOT Video Library.
Guide to High Throughput Toxicokinetic (HTTK) Parameters
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Hosted by: SOT Risk Assessment and Exposure Specialty Sections
Speaker:
HTTK mathematical models can provide predictions of absorption, distribution, metabolism, and excretion for chemicals without in vivo data. However, the models still require chemical-specific parameters to describe key aspects of toxicokinetics. Public repositories make in vitro measured toxicokinetic data available for more than 1,000 chemicals. These data have further been used to train quantitative structure-property relationship (QSPR) models, allowing predictions for novel chemicals without in vivo or in vitro data. This presentation (1) reviews key parameters needed for HTTK, (2) summarizes available in vitro and in silico means for attaining chemical-specific parameters, and (3) briefly reports estimated confidence in predictions made with in vitro and QSPR-based HTTK predictions.
The Successful Journey to Canada of Two Hispanic Toxicologists: Environmental and Occupational Perspectives
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Hosted by: SOT Hispanic Organization of Toxicologists Special Interest Group
Speakers:
Andres Henriquez is a Chilean toxicologist who earned a PhD from the University of North Carolina at Chapel Hill, USA, focusing on the impacts of inhaled air pollutants using in vivo models. Currently, Dr. Henriquez works at the Inhalation Toxicology Laboratory at Health Canada, where he investigates the interaction between inhaled materials, such as air pollutants, and diverse cellular models to better represent the pulmonary impacts of exposures.
Jairo Buitrago is a Colombian chemical engineer with 19 years of experience in the oil and gas industry. After gaining substantial expertise in occupational health and safety, he moved to Canada to further develop professional and technical skills. This journey led to the pursuit of a master’s degree in environmental and occupational health at the Université de Montréal. Following this achievement, Mr. Buitrago was accepted for accelerated entry into the PhD program in public health, specializing in toxicology and risk assessment.
An Update on Vaping in Two Parts
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Hosted by: SOT Risk Assessment Specialty Section
“Part 1: The Mixture Effect – Complexity of Electronic Nicotine Delivery System (ENDS) Aerosols Toxicity Assessment”
Speaker:
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Alexandra Noël, PhD, Associate Professor, Director of Inhalation Research Facility, Louisiana State University
As the use of electronic nicotine delivery systems (ENDS), also known as e-cigarettes, continues to rise, mainly in youth and young adult populations, it is crucial to understand ENDS health effects. ENDS refers to a wide-range of battery-operated devices with a primary function to deliver nicotine through inhalation by heating an e-liquid composed mainly of nicotine, propylene glycol (PG), glycerin (G), and flavors. This generates an ENDS aerosol that contains, in addition to the primary e-liquid constituents, harmful by-products resulting from the thermal degradation of PG and G, including acetaldehyde, formaldehyde, and acrolein, as well as metals, such as nickel and copper, that can leach from the heating elements of ENDS devices. The chemical profiles of ENDS aerosols, constituents, and concentrations are dependent on the e-liquid formulation as well as the operating settings of ENDS devices. Since ENDS aerosols are complex mixtures, recreating real-world ENDS exposure scenarios is necessary to capture the unique combined effects of the co-constituents. Thus, rigorous toxicity assessment of ENDS aerosols requires simulating ENDS exposures under controlled conditions, enabling the in vitro and in vivo study of individual constituents and/or doses, as well as the ENDS aerosol as a whole, to generate both science-based evidence and real-world data. Toxicological studies and experiments on ENDS that provide critical insights into potential toxic effects associated with vaping will be discussed during this webinar.
“Part 2: Considerations in Assessing Hazards, Exposures, and Risks of ENDS Compared to Other Tobacco Products”
Speaker:
Premarket Tobacco Product Applications (PMTAs) are submitted for any new tobacco product seeking a US FDA marketing order under section 910(b) of the Federal Food, Drug, and Cosmetic (FD&C) Act. Per the FD&C Act, PMTA applicants are required to provide sufficient scientific evidence to demonstrate that marketing of a new product is appropriate for the protection of the public health (APPH). The evaluation of a new product application involves an interdisciplinary review, including a nonclinical assessment of toxicological risks, before the US FDA determines whether a marketing order is appropriate. Specifically, according to § 1114.7(k)(1)(i)(B), a PMTA must contain, in part, the toxicological profile of the new tobacco product related to the route of administration, including, but not limited to, the genotoxicity, carcinogenicity, respiratory toxicity, cardiac toxicity, reproductive and developmental toxicity, and chronic (repeat dose) toxicity of the new tobacco product relative to other tobacco products. Experience from review of PMTAs for electronic nicotine delivery systems (ENDS) indicates that established harmful and potentially harmful constituents (HPHCs), as well as other constituents (e.g., ingredients, leachables), have the potential to confer substantial risk for adverse health effects. While there are decades of data regarding the toxicities associated with cigarettes, epidemiological data regarding the long-term risks from ENDS use will not be available for many years. Based on the US FDA’s statutory authority to comparatively evaluate ENDS in the APPH framework, we have developed a framework for the assessment of cancer risk of ENDS that implements a component-based hazard identification and tiering approach and then uses excess lifetime cancer risk estimations to better understand the cancer risks of ENDS. Our estimates indicate that there is a continuum of cancer risk in ENDS. Based on this experience, we have developed a qualitative scale to describe ENDS calculated cancer risk from <1% of the risk of 1R6F reference cigarettes to a higher end that exceeds 50% of the risk of 1R6F cigarettes. While a framework for non-cancer risk analysis is not yet available, the comparative framework for cancer risk analysis has allowed toxicological risks of new ENDS to be assessed in comparison to other tobacco products for PMTAs.