Session Summaries from SETAC Vancouver
View free session recordings from the SETAC North America 35th Annual Meeting in Vancouver, BC.
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- Bioavailability and Bioaccessibility: Critical Tools for Risk Management Decisions
Spencer Williams, Baylor University, and Glenn Hoeger, ARCADIS
Bioavailability and bioaccessibility are among the few remaining tools available to incorporate site characterization data into increasingly formulaic human health risk assessment and risk-based corrective action methodologies. Toxicity reference doses and carcinogenic slope factors used in human health risk assessment are derived from studies using highly soluble and, therefore, bioavailable forms of chemicals. Literature has reported that the relative bioavailability (RBA) of chemicals in environmental media (soil and sediment) is generally lower compared to the bioavailability of the same chemicals used in toxicity studies. Bioavailability is the measure of chemical absorption by receptors species based on in vivo studies, while bioaccessibility is the measure of a chemical’s solubility under exposure conditions using in vitro extraction procedures. Bioavailability testing can be expensive and increase the complexity of projects due to the use of animal models. Bioaccessibility studies are simple in vitro extract tests, but results must be correlated to in vivo studies if they are to be used in risk assessment. The purpose of this session is to provide practical applications of site-specific bioaccessibilty and bioavailability investigations in human health risk assessments, as well as calculation of site-specific risk-based cleanup levels and remedial decision-making.
Eight platform presentations were delivered in the session with four presentations addressing bioavailability and bioaccessibility of metals (principally arsenic), three presentations evaluating bioavailability of complex organic compounds (polycyclic aromatic hydrocarbons [PAHs]) and one presentation summarizing regulatory outlook for incorporating bioavailability into future risk management decisions. Presentations concerning arsenic bioavailability included two studies of paired in vivo amd in vitro analyses in pigs and rats. These presentations demonstrated that reliable site-specific RBA factors can be derived for arsenic from in vitro analyses in the presence of appropriate in vivo data. Presentations concerning bioavailability and bioaccessibility of PAHs demonstrated a greater variety of approaches to characterize site-specific RBAs compared to arsenic and lead. Two of the studies involved in vivo approaches in mice and rats providing direct measures of RBAs for PAHs in soil. The results of these studies can be easily applied to human health risk assessments. Overall, relatively consistent estimates of RBAs for PAHs were presented for all three different approaches. Finally, the importance of applying bioavailability evaluations to remedial decision-making was summarized from a regulatory perspective. The economic impacts from the application of bioavailability in the decision-making process are considered to enhance the numbers of sites that can be remediated without driving up the overall costs.
The bioavailability and bioaccessibility session was very well attended with over one hundred attendees for several presentations. The key points for the eight presentations included:
- In vitro bioaccessibility studies must be correlated to in vivo bioavailability studies to make RBA estimates for application in risk assessment
- In vitro bioaccessiblity results for arsenic can be used along with other speciation data to help characterize the bioavailability of arsenic in different soil types
- RBA of metals and PAHs in soil are all less than 100 percent with chemical source and speciation of metals have the greatest impact on the degree of how well a chemical may be absorbed from soil
- Bioavailability and bioaccessibility analyses represent a means to expand number of sites addressed for remediation in the future without significantly increasing costs
Authors’ contact information: Sp_Williams@baylor.edu and Glenn.Hoeger@arcadis-us.com
- Emerging Contaminants in the Marine Environment: Presence, Effects, Regulation
Robert M Burgess, Mark G Cantwell, Kay T Ho, USEPA ORD/NHEERL Atlantic Ecology Division, Marja H. Lamoree, Pim Leonards, VU University Amsterdam Institute of Environmental Studies
For the last decade, emerging contaminants (ECs) in freshwater environments have been studied intensively. As a result of this research, the presence and effects of some new use pesticides, pharmaceuticals, personal care products, and nanomaterials are much better understood. However, the presence and effects of ECs in the marine environment has not been as well investigated and much more research needs to be performed to address their presence and effects. Further, the development of science to support the regulations of ECs in the marine environment is in its infancy. To address these gaps in our understanding, a platform and poster session titled "Emerging Contaminants in the Marine Environment: Presence, Effects, Regulation’ was convened at SETAC Vancouver in November 2014. The goal of the session was to provide the audience with an up-to-date overview of aspects of the scientific issues associated with presence, effects and regulation of ECs in the marine environment.
The session consisted of eight platform presentations and 13 posters. Four of the platform presentations addressed the presence of ECs in the marine environment and included investigations of pharmaceuticals in the receiving waters around Auckland, New Zealand, sunscreen-related chemicals in the surface waters at beaches in the United States Virgin Islands National Park, and two studies focused on coastal sediment loadings of benzotriazoles along the northeast of the United States and pharmaceuticals, personal care products, and perfluoroalkyl substances in Elliott Bay, Puget Sound, Washington (USA). The next two platform presentations examined the accumulation of ECs and legacy contaminants by seabirds in northwestern Canada and in sharks and teleost fish in the southeastern United States. Next, the effects of sea lice pesticides, used in salmon aquaculture in northeastern Canada, was discussed. The final platform presentation provided an overview of the European Union’s Marine Strategy Framework Directive (MSFD) which includes the regulation of ECs. The 13 posters covered both laboratory- and field-based research related to several ECs including bisphenol S, alternative fuels, microplastics, siloxanes, polybrominated diphenyl ethers, perfluoroalkyl acids, and nanomaterials in marine environments ranging from the rivers discharging into the Black Sea to the coastal waters of Japan and South Korea.
The platform and poster sessions were well attended and there was a good exchange of questions and answers between the audience and the presenters. While the session was successful, it demonstrated that despite the excellent, ongoing research, much more work needs to be performed for the scientific community to properly assess the risks associated with ECs in the marine environment. For example, more efforts need to focus on prioritizing which ECs to monitoring for and regulate in the marine environment. Encouraged by the progress made in the session, the organizers of this session look forward to an equally successful session at the SETAC Europe 25th Annual Meeting in Barcelona, Spain, in May 2015.
Authors’ contact information: Burgess.Robert@epa.gov, Cantwell.Mark@epa.gov and Ho.Kay@epa.gov, email@example.com
- Evolutionary, Multigenerational and Epigenetic Effects of Pollutants (WATCH RECORDINGS)
Karel De Schamphelaere, Joe Shaw, Marie-Agnès Coutellec
The aim of this special symposium, organized by the evolutionary and multi-generational considerations in ecotoxicology and risk assessment of chemicals working group (EVOGENERATE) and sponsored by the SETAC Ecological Risk Assessment Advisory Group, was to promote a constructive tripartite discussion between academia, regulators and industry on multigenerational effects of pollutants as emerging issues in ecotoxicology, risk assessment and management. These effects include transgenerational, epigenetic and evolutionary effects. The session was organized around scientific presentations by invited speakers (Paul Klerks, Marie-Agnès Coutellec, Kaley Major, Elias Oziolor, Jessica Head, Tim Verslycke) which paved the way for a 30-minute final debate involving session chairs, speakers and the audience.
In order to guide the final discussion, the chairs started the session with a set of questions to be addressed during the debate. The speakers had received these questions prior to the conference and tried to address these during their talks. The questions and the answers that originated from the session included:
Question 1: Should we care about multigenerational effects of chemicals?
The answer to this question from the public was almost unanimously “yes.” Indeed, decades of data provide several excellent examples of the occurrence of multigenerational effects. In particular, a large and still growing number of laboratory studies highlight evolutionary potential (e.g. genetic adaptation). However, adaptation appears to be more difficult to demonstrate or evaluate in the field, probably in part due to lower environmental concentrations. Yet, a recent meta-analysis of evolutionary responses to PCB revealed some evidence that genetic adaptation may sometimes occur below regulatory limits (water quality criteria).
In the more specific case of transgenerational effects (e.g., epigenetic effects), the answer was also “yes.” However, the temporal disconnection between exposure (e.g. in early life or first generation) and effects (e.g., later in life or in subsequent unexposed generations) hampers our current ability to estimate effective concentrations in the field. Yet, some laboratory standard tests already exist that consider multi-generational effects (e.g., 2-generation mysid test), which could be extended to transgenerational effect testing.
Question 2: Are such effects desirable or undesirable (e.g., adaptation versus loss of genetic diversity), and are they relevant for regulation?
The possible issue here is that, while genetic adaptation can in itself be positive, it may also entail some evolutionary cost, by reducing genetic diversity and may thus lower the potential for natural populations to adapt to further environmental change including climatic and global changes. It was mentioned that such loss of genetic diversity might be triggered by environmental pollutants via natural (directional) selection as well as via random genetic drift as a result of pollutant-induced demographic reduction. It was also mentioned that, while population decline induced by chemicals may be followed by recovery in terms of numbers (when the chemical pressure is alleviated), the loss of genetic diversity may be an irreversible process. As population recovery ability is becoming an increasingly important regulatory protection goal, it was proposed that genetic diversity indices could become relevant as population descriptors in this context (see widespread use of genetics in conservation ecology).
Question 3: How should we quantify multigenerational effects of chemicals so that results are useful for risk assessment and risk management?
This question was addressed by several speakers and the discussion at the end focused on several aspects related to this question. First, besides selection experiments, which are perfectly suited for the assessment of evolutionary responses to particular substances, quantitative genetics can be used to estimate heritability of tolerance and response traits. These designs (mostly suitable in the laboratory) can help shed light on evolutionary and adaptation potential to chemical stressors as well on a population’s potential to face future stressors. Parameters that quantify such (potential) responses (e.g. selection strength, heritability) could be of broad value for ecological risk assessment, as they are population-level parameters that might be complementary to other parameters already in use in this area of risk assessment (e.g., population growth rate).
Second, while the availability of a high quality reference genome for a species (i.e., assembled and annotated, as in model species) indisputably facilitates the estimation of genetic effects, methods currently exist that do not require prior genomic information. Indeed, emerging Next Generation Sequencing-based methods (NGS) such as RADseq and RNAseq increase the power of Quantitative Trait Loci (QTL) mapping, Genome Scanning and Genome-Wide Association Studies, and allow mapping tolerance traits, testing micro-evolutionary hypotheses at the genome scale, as well as investigating molecular toxicity pathways at the transcriptome level (gene expression) in virtually any species of ecological or ecotoxicological importance. Such tools are expected to greatly enhance the genetic monitoring of populations as well as the estimation of extinction risks in the future. Specific tools can probably also be designed for a quick assessment of the status of a population regarding an evolved chemical-induced resistance (e.g., genotyping and allele frequency estimation at a resistance gene).
Third, there seemed to be a consensus among the audience that whenever a tool, a parameter, or a method show promise for application of evolutionary and multigenerational principles in risk assessment and management, its validation (through reproducibility testing, ring-testing, etc.) is an important consideration. Validation of methods is a prerequisite for use in risk assessment and management.
At the end of the debate, after having addressed the above question, a final discussion addressed the next steps to take for the future. This led to the idea that what really counts for ERA from a regulatory point of view is population decline and extinction. Therefore, the question that academia, industry and regulators need to tackle most primarily in the near future is how multigenerational and evolutionary principles (including genetics and epigenetics, as well as emerging technologies) can help to further refine population risk assessment.
If you want to be kept up-to-date on what’s going on in SETAC around these multigenerational and evolutionary considerations in risk assessment, of if you have a keen interest to contribute or share ideas to incorporate these considerations in risk assessment, let us know. You can find us at our EVOGENERATE working group website. You can also become a member of our workgroup and subscribe to our mailing list by sending a simple email request to the current workgroup chair. Everyone is welcome! Also, please visit the SETAC Live Learning Center for the recordings to experience first-hand this session.
Author’s contact information Karel.DeSchamphelaere@UGent.be
- Occurrence, Fate and Effects of Contaminants in National Parks, Wildlife Refuges and Other Protected Habitats (WATCH RECORDINGS)
Kelly Smalling, U.S. Geological Survey, and Colleen Flanagan Pritz, National Park Service
National Park Service lands, Wildlife Refuges and other protected areas host a variety of threatened and endangered species and sensitive ecosystems. Results of recent studies highlight the need to assess the occurrence and distribution of contaminants within protected ecosystems and evaluate their potential effects on native species. In order to address these concerns a session at the SETAC North America 35th Annual Meeting in Vancouver, Canada, focused on the occurrence and effects of a variety of legacy and emerging contaminants in protected areas on three continents (North America, Africa and Antarctica). The ultimate goal of the session was to encourage increased discussions among multidisciplinary and multinational scientists on the proactive and reactive management of chemical contamination and effects in sensitive park and refuge ecosystems. Speakers hailed from from the United States, Australia and South Africa.
The primary sources of contaminants to remote or protected lands include atmospheric transport from outside park boundaries, industrial activities such as oil and gas development within protected areas, wastewater treatment plants, coal transport by train, and commercial and household chemical use in close proximity to parks, as well as perturbations (such as dredging or storms) that re-suspend and mobilize contaminated sediments. Protected areas receive increased levels of scrutiny from resource managers. Presentations in the session demonstrated the benefits of using science to identify and document the sources of contaminants and their potential effects on wildlife and human health. These studies also serve to increase awareness of contaminants in, ironically, some of the most celebrated pristine ecosystems worldwide.
The session showcased state-of-the-art science on the different types and sources of contaminants present in protected areas, as well as potential effects on fish and wildlife. Presentations spanned a range of contaminants from legacy, regulated compounds such as DDT to control malaria outbreaks in South Africa to emerging contaminants including personal care products in wastewater from research stations in Antarctica, one of “the last untouched wilderness areas on earth.” Results of three, large-scale, reconnaissance studies were also presented to document the presence of contaminants in fish, dragonfly larvae and water from more than 50 national parks across the United States, understand the role contaminants may play in the decline of the Pacific lamprey, a subsistence fish for tribal people, and highlight the use biological indicators to determine estrogenic endocrine disruption in smallmouth bass throughout the Northeast. Other presentations focused on the potential sources of contaminants to protected areas including event-based exposures like hurricanes, oil and gas activities on refuges, and increased coal transport by train throughout the Pacific Northwest.
The platform session was a success and in addition to the well-attended talks, the session also included seven posters displayed during Thursday’s poster session. This session brought together a diverse group of scientists and facilitated broad discussions that bridged the gap between the science on and the management of protected areas. Parks and protected areas across the globe continue to be at risk to contaminants due to both internal and external threats. Through creative, collaborative efforts such as international coordination and crowd-sourced data collection, this body of work is expected to grow in the future. Management-driven research by academic institutions and government agencies is ongoing. Continued research is critical for understanding how to minimize contaminants and protect human and wildlife health in these ecosystems for future generations.
Authors’ contact information: firstname.lastname@example.org and email@example.com
- Assessing Contaminant Effects in Multi-stress Ecosystems
David Ostrach, Ostrach Consulting, and Larry Kapustka, LK Consultancy
The 16 presentations explored a wide range of issues that potentially confound understanding environmental consequences due to varying combinations of biological, chemical and physical stressors (e.g., salinity, selenium, seasonality and pulse exposures). Problems in coastal waters, marine reefs, urban environments and inland waterways were examined with assessment endpoints ranging from single species or community responses (e.g., salmon, benthic invertebrates, community structure and ecological functions) to integrative endpoints inferred from water quality metrics. Innovative experimental designs (Wijeveld, Dafforn, Meador, Marshall, Spromberg, Kupsco and Melwani), new applications of analytical techniques (Foran, Birrer, Landis and Whitehead) and application of regulatory issues (Kahuba, Saban, Morrison, Silva and Schiff). These presentations originated from North America, Europe and Australasia. Though clearly not a new challenge in environmental assessment and management, this collection of presentations represented advances in study design and execution that can be used effectively in other settings to unravel the complexity inherent in dealing with multiple stressors that have markedly different characteristics, operate on different components of the ecological system, have different modes of action and fluctuate in terms of intensity or magnitude across spatial and temporal scales. We encourage you to download the SETAC Vancouver abstract book for more details on presentations 268–275 and 361–368.
Author’s contact information: firstname.lastname@example.org and email@example.com
- Temporal Trends of Persistent Organic Chemicals in the Environment and Biota
Bommanna Loganathan, Murray State University, and Kenneth Sajwan, Savannah State University
The session “Temporal Trends of Persistent Organic Chemicals (POCs) in the Environment and Biota” discussed past, present and future trends of persistent chemicals in the environment and biota on the global scale. Environmental pollution by these man-made chemicals has been a global issue for more than half a century. Exposure to certain POCs may result in environmental and health effects in wildlife and humans. Since POCs are prevalent in air, water, soil and tissues of organisms throughout the world, trend monitoring studies are essential to make clear the behavior and fate of these compounds and to protect our environment and living resources. Behavior and fate of POCs vary with the ecosystems – terrestrial, atmosphere, aquatic (freshwater and marine), arctic and antarctic – that turn out to be a sink for these chemicals.
This session comprised eight platform and five poster presentations. Each presenter provided the audience with valuable take-home messages that included current findings as well as questions, which need to be addressed in the future. In general, the session covered salient aspects of the temporal trends of classical (PCBs, chlorinated pesticides) and emerging (brominated and perfluorinated compounds) POCs. For example, Lohmann presented interesting time trends of persistent organic pollutants (POPs) across the oceans, and the new data is very valuable for evaluating the risk of POCs to the open ocean biota. New data on temporal trends of classical (PCBs, chlorinated pesticides, dioxins and furans) and emerging pollutants (PBDEs and perfluorinated compounds) in the Great Lakes, Coastal (Savannah, Georgia, Sarasota Bay, Florida, and British Columbia), arctic and antarctic biota were presented. The data presented is valuable in understanding the present status and provided insight for possible future trends of POCs in the global environment and biota.
Authors’ contact information: firstname.lastname@example.org and email@example.com
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