Workshops

It is well known that analytical results need to be comparable in time and space and that traceability is the best way to achieve this goal. Per the internationally accepted definition, “Traceability is the property of the result of a measurement or the value of a standard whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties.”

Workshop presenters will provide updates on international metrology systems in chemical measurements and proper understanding of the terminology related to comparability, traceability, and uncertainty of analytical results.

Topics covered include the following presentations and practical examples:

• Chemical metrology and international systems supporting comparable measurements;

• Production, characterisation, certification, and use of reference materials;

• Calibration in chemical measurement, evaluating measurement uncertainty of results, and quality control; and

• Metrological traceability of mercury measurements in air, biological, and environmental samples.

Participants will then discuss both sections and the potential causes for disagreements.

Mercury is one of the least concentrated elements in the oceans. Concentrations are in the low-picomolar range (generally < 2pM). Low concentrations, in addition to different collection procedures, storage/preservation methods, and analytical techniques, have resulted in poor reproducibility of oceanographic mercury measurements between various laboratories. Sound analytical methods are needed to understand and interpret global mercury trends. To evaluate analytical performance we organized three international intercalibration exercises for total mercury and total methylmercury determination in seawater collected during the 2013 Dutch GEOTRACES MEDBlack cruise (GA04_leg2 - Black Sea), the 2014 French GEOTRACES GEOVIDE (GA01 - North Atlantic Ocean, and the 2015 GEOTRACES TransArcII (GN04 – Arctic Ocean). Each laboratory received a single sample bottle that had undergone the same cleaning procedure prior to sampling and each sample was preserved in the same manner. The 2013 exercise was intended as a broader screening with a maximum number (25) of participating laboratories.

Results indicated substantial disagreement between the participating laboratories, for both total mercury and methylmercury determinations. For the 2014 exercise we could only invite the 10 laboratories from the 2013 exercise, intercomparability of this second exercise was considerably better. For the 2015 exercise we invited again a larger panel of laboratories, and received results from 24 laboratories. Results indicated again substantial disagreement between the participating laboratories for both target species. The results call for more thorough investigation and efforts to obtain better intercalibration. Consequently, we organized the 2017 GEOTRACES Hg species intercalibration cruise June 12-23, 2017 in the Mediterranean Sea, hosted at the Mediterranean Institute of Oceanography.

We invite participants of all GEOTRACES intercalibration exercises and cruises, as well as scientists interested in marine mercury and low-level measurements to this workshop.

For the remainder of the workshop, participants will discuss both sections and the potential causes for disagreements. Followed by discussions on possible future developments needed to achieve traceable mercury measurements.

A revisitation and discussion of best practices to accurately measure mercury species in the atmosphere using commonly-deployed monitoring equipment. The workshop is designed for the experienced measurement specialist and will serve two primary purposes. The first is to discuss and revisit the Standard Operating Protocols, promulgated after a 2008 gathering of mercury measurement experts, for the operation of Tekran mercury speciation equipment deployed throughout the National Atmospheric Deposition Program's (NADP) Atmospheric Mercury Network (AMNet).

Discussions will center on lessons learned and insights gained, with respect to data collection and data reduction protocols, after nearly eight years of collective experience in deploying and operating the monitoring instrumentation. The second focus of the workshop is the summary and discussion of recently-documented artifacts in the measurement of Gaseous Elemental Mercury (GEM), Gaseous Oxidized Mercury (GOM), and Particulate-Bound Mercury (PBM).

Specific discussions will focus on identifying ambient conditions and chemical/physical parameters associated with observed measurement artifacts; attempts to bound the range of uncertainty in the measurement of atmospheric mercury species; and efforts to mitigate the measurement biases and artifacts and/or to correct ambient data.

Mercury and its compounds can enter the human body with contaminated air, food, and water. Certain exposure pathways are important for exposure to different types of mercury. For example, the main pathway of exposure to mercury vapor is inhalation, while exposure to methylmercury occurs through consumption of contaminated food. Many environmental monitoring data are necessary to model and calculate an internal dose, which is critical to assess health risks of mercury, and predict possible health impacts. Human biomonitoring (HBM), which involves measuring concentrations of different forms of mercury in human tissues, is a simple and reliable method to assess exposure to mercury from all sources.

The Minamata Convention requires identification of population groups at risk of mercury exposure and the adverse health impacts, globally and at a national level, especially of population groups living in potentially contaminated sites. UNEP and WHO recognize mercury HBM as the most effective approach for identification of exposed population groups, and the basis for advising governments on risk reduction measures. HBM is necessary to evaluate how effective these measures are and to adjust them, if necessary. Moreover, at the individual level, mercury HBM allows providing advice to individuals on how to reduce exposure to mercury. Hence, mercury HBM is critical to identifying population groups at risks, predicting potential health effects, developing recommendations on targeted risk reduction measures at national, local and individuals’ levels, and to evaluate their effectiveness.

To be able to implement mercury HBM globally national monitoring programs should be developed and implemented, including the development of approaches to identify target population groups, estimation of a sampling size and adoption of standard procedures for sampling and mercury analysis; strengthening of capacities of national analytical laboratories, to ensure their quality and reliability. At all steps of the development and implementation of national monitoring programs, ethical and cultural aspects of HBM must be taken into account.

The workshop will allow discussion of the following topics:

1. The role of mercury HBM in identification of population groups at risks;

2. Challenges and benefits of developing and implementing national mercury HBM programs;

3. Building national capacities to perform mercury HBM studies/surveys;

4. The use of mercury HBM to assess effectiveness of risk reduction measures; and

5. The role of WHO and other international organizations in supporting national and regional HBM efforts

Our understanding of the biogeochemical cycling of mercury in marine systems remains hampered by uncertainties and limitations of experimental data and an inadequate understanding of individual processes. However, it is a rapidly evolving field; new potential methylators are identified, there is a new focus on the availability of distinctive mercury pools for aquatic processes, and we are learning more about how different drivers caused by, for example, land use and global warming can impact the loading and cycling of mercury in marine systems. In this workshop, we want to bring scientist working with model and experimentally based research together for a creative and inspiring discussion. We want to address the processes where the largest uncertainties are found when focusing on the ecosystem and global scale and discuss how we best move forward to close these gaps.

To inspire the discussion, Anne Sorensen (Stockholm University, Sweden) will start by introducing major gaps in our knowledge of the marine biogeochemical cycle. She will focus on limits in our current understanding that becomes apparent when introducing experimental data into a biogeochemical modeling framework. This will be followed by short overview talks focused on some of the biogeochemical processes identified as key processes to address in future research. State of the art methods and uncertainties related to these will be presented together with a summary of emerging techniques that are likely to improve our estimates in the future. The selected processes include Hg redox chemistry (Alexandre Poulain, University of Ottawa, Canada), the availability of mercury for methylating bacteria (Jeffra Schaefer, Rutgers University, USA) and methylating/demethylation rates (Sofi Jonsson, University of Connecticut, USA). Each talk will be followed by a discussion.

Mercury contamination by point sources (e.g., mining, industry) occurs globally. Assessment and management of these sites can benefit from the substantial body of research into Hg cycling in the environment, risks posed to humans and wildlife, and methods for remediation. This workshop will cover identification of potential Hg-contaminated sites, characterization of the nature and extent of contamination, development of conceptual site models of Hg transport and fate, assessment of potential risks to human health and the environment, and risk management and remediation. Actual examples of site assessment and management will be discussed. Particular attention will be paid to areas where research is needed to better assess Hg behavior, risks, and remedial options. The target audience includes managers of sites with identified or potential mercury issues, graduate students interested in applied environmental science, and researchers curious to see how scientific findings are used in decision-making and to learn what additional research is needed in the context of practical problems.

Specific topics include:

• Types of Hg-contaminated sites

• Pertinent regulations

• Site investigations

• Conceptual site models

• Ecological and human health risk assessments

• Management options including implementation of remediation measures

The Mercury Game is a negotiation simulation designed to teach people about the role of science in international environmental policy making.

Despite decades of scientific work on issues such as ozone depletion, climate change, and toxic chemicals, effectively communicating scientific uncertainty remains a major challenge in all environmental treaty negotiations.

Strategies for incorporating scientific information into policy include developing scientific assessments, setting up subsidiary bodies to treaty negotiations, and framing the information in an appropriate manner. How scientific information is perceived has been, and will remain, a key challenge facing all international environmental treaty-drafting efforts.

This mercury game is a role-play simulation aimed at scientists, students, and decision makers. Playing the game will help participants explore the consequences of representing scientific uncertainty in various ways in a policy context. The game focuses on the credibility of various sources of technical information, strategies for representing risk and uncertainty, and the balance between scientific and political considerations. Ultimately, the role play should help to make clear how scientific information can be favorably employed in an environmental treaty making process. The results of the game will be used in a doctoral research project on the relationship between science and policy in international environmental negotiations.