Mark S. Johnson, US Army Public Health Center, and Lyle Burgoon, Engineering Research and Development Center
The Ecological Risk Assessment Global Interest Group (ERAIG) is an active, engaged group dedicated to advancing and promoting emerging science to improve the methods used to estimate risks to non-human receptors from exposures to chemicals in the environment. A significant driving force has historically been regulation where jurisdictions require ecological risk assessments for various applications, ranging from assessing contaminated environmental sites to making decisions on the use of new chemicals expected to be released in the environment. The primary questions behind regulations have not changed much through the years; however, guidance and metrics do vary between jurisdictions. Academia, government and industry have provided data and research to help frame ecological risk assessment questions appropriately and, for many topics, have provided empirical evidence to support what can be reasonably accomplished to address many of these questions.
In many ways, the methods currently used in ecological risk assessments have not changed much, and typically, more data not new methods have been predominantly required. However, opportunities exist to improve methods, and some recent regulatory support has helped to advance research on non-animal methods. Recent advances in understanding mechanism through adverse outcome pathway (AOP) analysis has assisted in providing a greater understanding of phylogenetic and physiologic differences that help in extrapolation of toxicity data between species. Differences that exist can often be explained due to species-specific toxicodynamic and toxicokinetic relationships, and understanding both are important to assist in extrapolation. AOP and toxicogenomics technologies are advancing for many species and promise to help provide more detailed information of adverse effects that could also be valuable in field applications.
Endpoints of concern for many species have moved beyond mortality, growth and reproduction, particularly for species where more information can be collected. The “ecological” aspect (i.e., understanding the influences of how xenobiotic exposure affects the way animals and plants interact with their environment) of ecological risk assessment has advanced as well. Superfund requires only investigations relative to chemical exposures, not other stressors, which can be relatively more important. In many cases, jurisdictional constraints have had the influence of restraining research and practical assessment of improving our relative view of chemical versus “other” stressors and their interactions. Research efforts in understanding exposure is less extensive than research conducted to understand effects. Simple life history traits, such as food consumption rates, daily foraging ranges and even life span data, are not available for many species. In many cases, ecological aspects of how sublethal effects influences animal, plant or environment interactions are largely unknown, and the term “ecological” in ecological risk assessment has largely inferred “toxicological effects to non-human species from environmental releases.” Understanding population-level consequences from chemical exposures has and continues to be an area of focus within the ERAIG, and insights on new approaches and data are encouraged.
Improving exposure estimates for ecological receptors also continues to be a focus area. Individual-based models that allow for individual choices, which can influence exposure in a heterogeneous landscape, have shown excellent results with highly vagile species. However, many of these models have limited utility for sessile or species that do not move much within the landscape. Still, understanding effects on wildlife from non-oral exposures (e.g., dermal, inhalation) remain a challenge, as do lapses in empirical data for many life history attributes described in the preceding paragraph. Work has advanced in areas defining tissue-specific concentration toxicity benchmarks that reduce the need to model exposures. Spatially explicit models have also been developed for fish that consider habitat and sediment concentrations of organics in predicting body burdens.
The ERAIG has also been engaged with many other interest groups collaborating in workshops, Focused Topic Meetings (FTM) and other projects of shared concern. The ERAIG has been involved with helping to design ERA training modules that have been used to help provide information to others regarding ERA conduct and goals. Examples include modules developed specific to the African geo-region, general modules for teachers and even for the U.S. Congress during deliberations on the Frank R. Lautenberg Chemical Safety for the 21st Century Act. Short courses for Brazil and Israel are also being discussed. ERIAG was engaged in the Risk Assessment of Chemical Mixtures SETAC North America Focused Topic Meeting in September 2017 and the Environmental Risk Assessment of Per- and Poly-Fluorinated Alkyl Substances (PFAS) SETAC North America Focused Topic Meeting in August 2019 to discuss the state of the science on the risk assessment of PFAS. This meeting included experts from academia, government and industry from around the world to learn about recent advances, understand how various jurisdictions are interpreting the science, and identify key research needs to develop a roadmap on how best to proceed. Working with the Wildlife Toxicology Global Interest Group, another workshop is being planned, titled “Wildlife Ecotoxicology in the 21st Century: Integrating Advancements in Ecology, Toxicology and Conservation into Risk Assessment Workshop,” where goals include bringing the latest science to the forefront while also outlining data requirements needed to advance the science further.
These events are brief examples of efforts occurring within the ERAIG; many more projects within subcommittees are also underway. All happen through engaged efforts of our members, and the ERAIG is actively seeking and encouraging participation from all interested within the SETAC membership. The ERAIG is particularly interested in encouraging student participation to help bring in new ideas and enthusiasm to the group. Most in-person meetings occur during the North America and Europe annual meetings and are open to all. Individuals who participate in specific projects meet based on their specific schedules and demands of the project or subcommittee. Please feel free to contact Mark Johnson or Lyle Burgoon if you have any questions or requests.