Creating a prosperous and thriving environment

Join us at The Society of Environmental Toxicology and Chemistry Conference (SETAC) 2023 November 14-16 in Louisville Kentucky to discuss environmental risk assessments and more.
 
Advancing research in environmental toxicology is critical to identifying and mitigating risks to humans and the ecosystem alike. Our array of presentations and posters at the upcoming SETAC conference represent environmental challenges in the industry and explore science-based solutions, models and studies that strengthen knowledge about environmental risk.

A Simple Narcotic Toxicity Model Extended to Complex Environmental Toxicity Issues
 

Presentation by Joy A McGrath, GHD and Christopher J Fanelli, Mutch Associations

A simple linear model was developed to predict the toxicity of narcotic chemicals. The model uses a chemical property that describes the ability of chemicals to partition into the organism lipid. The fundamental premise of the model is that when the chemical concentration in the organism lipid reaches a critical concentration, effects are observed. The model is utilized by regulatory agencies and risk assessors to predict the toxicity of chemicals that are found in petroleum products and make their way into soil, sediment and surface water. The model has been extended to incorporate conditions that change the toxicity of these chemicals such as UV light and pressure. 

Effective Predictive Domain: The Hidden but Powerful Risk Assessment Variable 
 

Poster presentation by Samantha Townsend, Francis Ramacciotti, Tamara House-Knight and Timothy Walsh, GHD

The effective predictive domain (EPD) is a variable that describes the physical/chemical properties in water that cause chemicals to not permeate the skin, i.e., it determines whether dermal contact is a relevant exposure pathway that can be modeled from water. However, it is an often-overlooked variable in human health risk assessment, most likely because evaluation of the term is not directly necessary to "run numbers" and calculate risk estimates. This poster will explore how ignoring this variable can have a significant impact on the evaluation of certain chemicals in a risk assessment.

Reasonable Maximum Exposure in Environmental Risk Assessment - Multiple Interpretations and Apparent Spontaneous Expansion
 

Poster presentation by Francis Ramacciotti, Tamara House-Knight and Samantha Townsend, GHD

Over the past three decades institutional knowledge has been lost and when combined with other economic and social pressures, multiple interpretations of what is and is not included in Reasonable Maximum Exposure (RME) have emerged. We provide a summary of the background and basis for the RME, an understanding of what is typically included (e.g., exposures that represent in aggregate ~95% of the population), and an identification of a few key aspects that are imperative to risk characterization, but not included yet often associated with the RME (e.g., uncertainty tied to toxicity).
 

An Ecological Risk Assessment of Perfluorooctane Sulfonic Acid (PFOS) Exposure to Piscivorous Receptors: Evaluating Sources of Uncertainty

Poster presentation by Stephanie A. Maggio and William A Schew, GHD

PFAS are contaminants of concern that are detected ubiquitously in the environment and have been shown to cause toxic effects to exposed organisms. Ecological receptors can be exposed to PFAS through direct contact with contaminated environmental media and uptake via food web interactions. In ecological risk assessments, when appropriate food chain data are lacking, bioaccumulation factors can be used to derive the missing input parameters. However, this introduces varying levels of uncertainty and can alter risk characterizations and the resultant understanding. This poster presents an evaluation of the exposure of piscivorous receptors to PFOS to ellucidate how different sources of uncertainty have the potential to affect ecological risk characterizations.

Why Crisis Communication is in a Crisis

Poster presentation by Tamara House-Knight and Francis Ramacciotti, GHD

With states and the federal government releasing environmental justice laws and actions, disadvantaged communities are still experiencing inconsistent responses to environmental releases. Impacted communities are often under-informed and or misinformed, left feeling unheard and that there is a lack of accountability for the harm caused. This presentation will provide a comparison of responses to environmental releases impacts involving three real-world examples. It also serves as a practical guide for regulators, practitioners and the general public to see how environmental justice, accountability and risk communication are interconnected concepts related to the environment and society.

Assessing the differences between adult and nymph Amblyomma americanum (Lone Star) Ticks as viable sentinels for the detection of Per - and polyfluoroalkyl substance contamination
 

Poster presentation by Timothy Walsh, GHD

Per- and Polyfluoroalkyl Substances (PFAS) are listed as emerging contaminants due to their widespread use, persistence in the environment, and potential for adverse health effects. A recent study demonstrated that ticks, including the lone star tick, are potentially viable sentinels for the detection of environmental PFAS contamination. To better understand this relationship and determine the most effective sentinel, direct comparisons between life stages within a single tick species should be carried out. This work would provide a more robust understanding of a relatively novel method of PFAS detection and could provide a lower effort and more direct method for determining ecological burden. 

Assessment of Intermittent Lead Exposures using the Integrated Exposure Uptake Biokinetic Model

Poster presentation by Hyland Herring, GHD

The United States Environmental Protection Agency (USEPA) has established approaches for evaluating lead exposure, traditionally for constant and chronic exposure. However, in certain situations the only exposures are intermittent or transient, which need evaluation. The USEPA updated its Integrated Exposure Uptake Biokinetic (IEUBK) Model in 2021 and released a guidance document related to intermittent exposures in 2003, however, it has yet to specifically evaluate intermittent exposures. This poster looks at the assessment of intermittent lead exposure using the IEUBK model and evaluates the potential uncertainties to show how the calculated numbers are safe.

Understanding ECEJ Census Data for a Large Group of Manufacturing Sites with a Customized Dashboard

Poster presentation by Tom Fewless and Tamara House-Knight, GHD

The US government has made census information available to encourage analysis and consideration of impacted communities with a focus on Environmental, Climate and Economic Justice (ECEJ). This tool provides analysis and recommendations to enable understanding of and interaction with the census data through an interactive dashboard. The objective of this tool/dashboard is to assist with proactively engaging marginalized communities and understanding the ECEJ metrics. This presentation will provide an overview of the dashboarding tool, how it analyzes the data, its use and the results for a large manufacturing business with property in the US.