Special Sessions

The fate of mercury and its interaction with selenium in biota is undeniably a cutting-edge research area, as evidenced by the number of research groups delving into it and the burgeoning publication of high-impact articles on the subject. The discovery of HgSe bioinert nanoparticles in marine mammal tissues initially, and more recently in fish and seabirds, robustly supports the hypothesis of selenium species playing a crucial role in mercury detoxification. However, several questions remain unresolved. For instance, which selenium species are involved in these processes? What is the impact of dietary selenium (species) on the fate of mercury in farmed animals, such as those in aquaculture? Furthermore, what analytical strategies should be employed to track the fate and interaction of mercury, particularly its interaction with selenium, in biological systems, among other inquiries? The use of complementary approaches is essential to address these critical questions effectively.

The impact and outcomes of this session are primarily focused on advancing our currently limited understanding of the interaction between mercury and selenium in living organisms. This research aims to contribute to a better comprehension of such mechanisms in both marine and freshwater systems, thereby setting the foundation for future guidelines for fish consumers in various exposure conditions, ranging from European consumers to the Amazon riverine population. Moreover, these efforts will provide policymakers with robust datasets to support their decisions. Furthermore, this session will foster the development of new collaborations among attendees, driven by the discussions facilitated through the proposed oral and poster presentations.

Mercury pollution, a global environmental concern, poses significant threats to both ecosystems and human health. The Asian region, with countries like China, India, Bangladesh, Thailand, Indonesia, Vietnam, and the Philippines, is especially susceptible to this pollution due to its rapid industrialization, land-use changes, extensive artisanal and small-scale gold mining, and increasing coal-fired power production. This session aims to bring to light the exceptional challenges and impacts of both legacy and current mercury pollution in this region and inspire meaningful action towards a healthier and safer mercury-free future.

We anticipate that this unique session will offer significant perspective and aid in the worldwide endeavours to combat mercury contamination while simultaneously addressing the particular concerns of the Asian region.

Mercury poses many challenges for the oil and gas industry along the entire value chain, including corrosion issues, the potential for worker exposure, the generation of mercury rich waste products and potentially environmental release. This session will focus on how the industry is dealing with these issues, what has been learnt most recently in terms of managing mercury and understanding where there is potential for release to the environment.

Bioconcentration, bioaccumulation, and biomagnification of mercury (Hg) and methylmercury (MeHg) in marine food webs serves as a crucial link between environmental Hg cycling and the risks to humans associated with the consumption of MeHg-contaminated seafood. Exposure and bioaccumulation of Hg species is also a likely stressor for marine and terrestrial organisms, with the potential of threatening wildlife populations – especially for high trophic levels species – although clear causal relationships are still lacking.

Hg levels in marine organisms are affected by several factors including Hg speciation, growth dynamics and physiology of individual organisms, feeding habits and interactions, as well as ecosystem structure. Some of these factors can change during an organism’s life cycle, and others can be highly dynamic in time/space, with their natural range of variability further amplified by climate change. To unravel the most important mechanisms driving bioconcentration, bioaccumulation, and biomagnification, it is essential to integrate expertise from field observations, laboratory experiments, and model development. However, bridging these interdisciplinary boundaries can often be challenging due to the very different methodological approaches. In this interdisciplinary special session, our objective is to bring together Hg specialists from various fields to share expertise and discuss insights on the bioaccumulation of Hg and MeHg. By combining our knowledge through collaboration, we aim to gain new perspectives on this critical process.

Our understanding of the biogeochemical cycling of mercury in the Southern Hemisphere (SH) and the tropics is still poor compared to the advances in mercury research in the Northern Hemisphere (NH). There remains a considerable scope for advancing the field of mercury science in the SH and to establish and maintain collaborative networks to promote environmental mercury monitoring and comparative and integrative research.

This session seeks to emphasize the natural and anthropogenic differences between hemispheres that limit the application of NH data in understanding the mercury cycle in the SH. This session intends to bridge this knowledge gap by inviting presentations and fostering discussions on mercury research in the SH and tropical regions.

Accurate, verified atmospheric measurements are critical to understanding the mercury biogeochemical cycle. Unfortunately, the commercially available oxidized mercury instrumentation is merely qualitative, and no commercial instruments are available for routine, multi-point calibration of elemental nor oxidized mercury. New methods to fill these gaps are being developed and deployed by research groups around the world.

Presentations for this session will discuss new techniques for measuring and verifying atmospheric elemental and oxidized mercury, including laboratory studies, field deployments, and metrological analyses. We will prioritize submissions that focus on new technologies, rather than existing techniques that are already known to be deeply flawed (e.g., KCl denuder-based oxidized mercury measurements). We will also prioritize submissions that include traceable verification of measurement results.
This special session will target the atmospheric mercury community, including those researching atmospheric mercury, those developing gas-phase mercury measurement and validation methods, and government entities that need to monitor atmospheric mercury.

The outcome of this special session will be movement of the atmospheric mercury community towards more accurate and better verified atmospheric mercury measurements. Attendees will gain information about new methods that are becoming available and be able to build collaborations to accelerate method development and adoption.

This session aims to bring together scientists to discuss the latest results using advanced microbial and geoscience-associated techniques to explore mercury transformation by microorganisms in various environments, including the reduction and methylation of mercury and the methylmercury degradation. Symposium talks will focus on the processes and drivers of microbial mercury transformation and associated communities based on combined approaches of high-throughput meta-omic analyses, isotope tracer and ecological modelling to identify community composition and metabolisms linked to mercury biogeochemistry. We also welcome presentations on element biogeochemical cycles potentially associated with mercury biotransformation in environments. The target audience includes all researches who are concerned with mercury environmental processes, which are fundamental to understanding mercury biogeochemical cycles.

Through communications in this session, we aim to attract more attention from mercury and related researchers worldwide. The outcome of our special session will advance our understanding of mercury biogeochemical cycles across ecosystems, and the new results will benefit improved prediction and risk control of mercury accumulation in environments.

Statistical and machine learning techniques and models are increasingly being adopted and improved for Hg science. In combination with chemical transport models (CTMs) and global biogeochemical cycle models, which have been developed for global Hg cycling and utilized in the Hg community for decades and explicitly represent key processes, modeling and data analysis that applies techniques from statistics and machine learning offers the potential to improve model performance and leverage global observation networks. This session focuses on recent advances in statistical/machine learning approaches as applied to Hg atmospheric processes and global biogeochemical cycling, including model development and methodology, innovative integration with observations, application of these models to quantify the impacts of natural and anthropogenic perturbations on global Hg behavior, and future perspectives of model development. The key scientific questions of this session are as follows:

What types of statistical and machine learning approaches have been applied to better understand global Hg cycling? How can measurement information using advanced quantitative techniques (e.g., isotopes, improved knowledge of atmospheric chemistry) be incorporated into process-based and machine learning models? How can data from global Hg observation networks be better leveraged using CTMs and statistical/machine learning approaches? What advances in modeling and quantitative techniques can assist in better quantifying the impacts of natural and anthropogenic perturbations on global Hg cycling? How can we combine approaches from statistical/machine models with CTMs to improve our understanding of global Hg behavior?

Mercury is a highly volatile substance that travels long distances in the atmosphere and remains in the environment for a very long time, so global information is important for analyzing the pollution situation and taking action. With the signing of the Minamata Convention on Mercury in 2013 and its entry into force in 2017, international cooperation projects for capacity building, technical cooperation, and the formation of monitoring networks to survey and monitor mercury levels in the environment have become active, and new surveys and monitoring are being promoted even in areas with little existing data, called “gaps”.

The objective of this session is to present the ongoing collaboration of the international community in mercury measurement and analysis.

Name:          Igor Živković (principal contact)
Affiliation: Jožef Stefan institute, Ljubljana, Slovenia
Email:          igor.zivkovic@ijs.si

Name:         Akane Yamakawa
Affiliation: National Institute of Environmental Studies, Japan
Email:          yamakawa.akane@nies.go.jp

Name:         Koichi Haraguchi
Affiliation: National Institute for Minamata Disease
Email:         KOICHI_HARAGUCHI@env.go.jp

Name:          Milena Horvat
Affiliation: Jožef Stefan institute, Ljubljana, Slovenia
Email:          Milena.horvat@ijs.si

Ensuring the reliable comparison of measurement results holds critical importance in the effective evaluation of the Minamata Convention. This demands a thorough application of metrology principles, which form the scientific bedrock of contemporary quality standards. Accurate and traceable determination of mercury levels in the air, water, soil, and living organisms is indispensable for monitoring pollution, evaluating the risks posed by human and ecological exposure, and devising efficient strategies to combat these challenges. To establish trust and global comparability in environmental mercury data, international organizations have set forth guidelines and offered certified reference materials as well as regular organization of interlaboratory studies. Nevertheless, the measurement of mercury concentrations is inherently intricate, given the existence of multiple sources of error and variability.

Interlaboratory exercises and proficiency testing programs for the analysis of mercury in environmental samples play a central role in assuring the precision and reliability of data used in environmental monitoring and regulatory compliance. These programs empower laboratories to assess their analytical capabilities, pinpoint potential sources of error, and enhance their methodologies. Furthermore, the outcomes of proficiency testing and collaborative initiatives involving various laboratories serve to boost confidence in the accuracy of mercury measurements, thereby facilitating well-informed decision-making and the safeguarding of ecosystems and human health, particularly for the effectiveness evaluation of Minamata Convention.

Uncertainties in mercury measurements can be rooted in factors such as the collection and preparation of samples, instrument calibration, and data analysis. In addition, the complexities associated with the behavior, speciation, and transformation of different mercury species are influenced by a range of factors, including natural sources, human-induced sources, and microbial processes. The intricate nature of mercury behavior and transformation within diverse environmental contexts adds to the complexity of analyzing mercury speciation. Metrological considerations, such as standardization and traceability to international standards, matrix effects, precise quantification of various mercury species, proper sample handling, and the evaluation of analytical techniques, have a substantial impact on data quality, comparability, and the integration of data from various sources.

Present uncertainties in models describing the transport and transformation of mercury in the environment primarily arise from the intricacies of the mercury biogeochemical cycle across the various compartments of the environment. Progress in metrological practices and standards will contribute to the reduction of these uncertainties, an improved comprehension of mercury’s behavior within ecosystems, and the facilitation of the development of more effective strategies for managing and mitigating the impact of mercury pollution on the environment and human health.

The principal objective of this presentation is to highlight the latest advancements in traceable mercury measurements on a global scale. This session is intended for experts specializing in mercury analysis and speciation, modelers, and other individuals reliant on measurement results. Additionally, it caters to national metrology institutes, standardization bodies/agencies, and manufacturers of instrumentation.

The topics involve the following:

• ensuring the traceability and reliability of mercury analysis and speciation in environmental samples (air, soil, sediments, water) and biological samples (humans, food, animals, aquatic biota, and plant samples) (up to 3 talks);
• validating stability and interspecies conversion in low air levels, integrating into uncertainty evaluation. Establishing traceability and reliability in measuring mercury analysis and speciation in the gas phase. Developing traceable primary standards and assessing measurement uncertainty. Comparing methods for generating mercury gas standards at relevant concentrations (up to 3 talks);
• disagreement between measured and model-predicted reactive mercury in air: is it measurement uncertainty or inaccurate modelling approaches? (1-2 talks);
• discussing international programs requiring traceable mercury measurements in environmental and biological samples (NIES, ERM, IAEA and NIST) (up to 2 talks);
• sharing field experiences and requirements from user groups, including researchers and industries. (1 talk from industry);
• addressing traceability in bulk and compound-specific isotope signature measurement methods (1 talk);
• exploring perspectives from instrument producers on securing metrology support for mercury analysis and special progress on standardized methods to harmonize the measurement of Hg (1-2 talks);
• Measurement uncertainties and human exposure assessment models (1 talk, posters).

 

We plan 12 speakers and a number of posters, which constitute two session each with one Keynote speech. We shall combine presentations from key metrological institutions worldwide, the participants of dedicated projects, leading research institutions world-wide in the area of mercury speciation analysis, instrument producers, reference materials producers, participants from standardization bodies as well as users of analytical results, such as environmental modelers and risk assessors.